GLASS

Abstract

Manufacturing is facilitated while deflection is suppressed, and transmission ability is increased. A glass (10) contains SiO.sub.2: 40% to 60%, B.sub.2O.sub.3: 0.01% to 15%, and Al.sub.2O.sub.3+rare earth oxide: 0% to 20% as expressed in mol % on an oxide basis, and the ratio of the total content of Al.sub.2O.sub.3 and RO to the total content of SiO.sub.2, Al.sub.2O.sub.3, and RO (that is, (Al.sub.2O.sub.3+RO)/(SiO.sub.2+Al.sub.2O.sub.3+RO)) is 0.38 or more.

Claims

1. A glass comprising: SiO.sub.2: 40% to 60%, B.sub.2O.sub.3: 0.01% to 15%, and Al.sub.2O.sub.3+rare earth oxide: 0% to 20%, as expressed in mol % on an oxide basis, wherein a ratio of a total content of Al.sub.2O.sub.3 and RO to a total content of SiO.sub.2, Al.sub.2O.sub.3, and RO, which is a total content of divalent oxides, (that is, (Al.sub.2O.sub.3+RO)/(SiO.sub.2+Al.sub.2O.sub.3+RO)) is 0.38 or more.

2. The glass according to claim 1, comprising: SiO.sub.2: 41% to 59%, B.sub.2O.sub.3: 1% to 12%, Al.sub.2O.sub.3: 5% to 20%, and (Y.sub.2O.sub.3+Gd.sub.2O.sub.3+Ta.sub.2O.sub.5+La.sub.2O.sub.3+Nd.sub.2O.sub.3+Nb.sub.2O.sub.5): 0.5% or more, as expressed in mol % on an oxide basis.

3. The glass according to claim 1, wherein a transmittance of light with a wavelength of 308 nm at a thickness of 0.7 mm is 30% or more.

4. The glass according to claim 1, wherein $0.1\left\{\left({\mathrm{Al}}_2{O}_3+\mathrm{MgO}\right)/\left({\mathrm{SiO}}_2+{\mathrm{Al}}_2{O}_3+B_2{O}_3+\mathrm{MgO}\right)\right\}1,$ $0.3\left(\mathrm{MgO}/{}_{\mathrm{RO}}\right)1,\mathrm{and}$ $0\%{\mathrm{Al}}_2{O}_3+\mathrm{rare}\mathrm{earth}\mathrm{oxide}20\%,$ as expressed in mol % on an oxide basis, wherein RO refers to a total content of divalent oxides contained in the glass.

5. The glass according to claim 1, wherein when a content of an oxide R.sub.xO.sub.y contained in the glass in terms of mol % on an oxide basis is represented by [R.sub.xO.sub.y], a Young's modulus parameter Y calculated by Formula (1) is 0.8 or more, a thermal expansion parameter C calculated by Formula (2) is 1.2 or less, and a liquidus parameter L calculated by Formula (3) is 10.5 or less, $\begin{array}{cc}Y=\left(123-0.54\left[{\mathrm{SiO}}_2\right]+0.3\left[{\mathrm{Al}}_2{O}_3\right]-1.15\left[B_2{O}_3\right]+0.21\left[\mathrm{MgO}\right]-0.2\left[\mathrm{CaO}\right]-0.1\left[\mathrm{SrO}\right]-1.2\left[\mathrm{BaO}\right]+\left[{\mathrm{Li}}_{2}O\right]-2.8\left[K_{2}O\right]+0.05\left[\mathrm{ZnO}\right]+1.46\left[{\mathrm{ZrO}}_2\right]-0.05\left[{\mathrm{TiO}}_2\right]-1.6\left[Y_2{O}_3\right]+1.35\left[{\mathrm{Gd}}_2{O}_3\right]+1.37\left[{\mathrm{La}}_2{O}_3\right]+\left[{\mathrm{Ta}}_2{O}_5\right]\right)/100,& \left(1\right)\end{array}$ $\begin{array}{cc}C=(14.098-0.1245\left[{\mathrm{SiO}}_2\right]-0.131\left[{\mathrm{Al}}_2{O}_3\right]-0.101\left[B_2{O}_3\right]-0.051\left[\mathrm{MgO}\right]+0.013\left[\mathrm{CaO}\right]+0.053\left[\mathrm{SrO}\right]+0.018\left[\mathrm{BaO}\right]+0.041\left[{\mathrm{Li}}_{2}O\right]+0.395\left[{\mathrm{Na}}_{2}O\right]-0.066\left[\mathrm{ZnO}\right]-0.033]{\mathrm{ZrO}}_2]-0.072\left[{\mathrm{TiO}}_2\right]+0.035\left[Y_2{O}_3\right]+0.074\left[{\mathrm{Gd}}_2{O}_3\right]+0.074\left[{\mathrm{La}}_2{O}_3\right]-0.091\left[{\mathrm{Ta}}_2{O}_5\right])/5,\mathrm{and}& \left(2\right)\end{array}$ $\begin{array}{cc}L=\left(-642.5+20.6\left[{\mathrm{SiO}}_2\right]+31.9\left[{\mathrm{Al}}_2{O}_3\right]+2.85\left[B_2{O}_3\right]+11.24\left[\mathrm{MgO}\right]+17.3\left[\mathrm{CaO}\right]+1.75\left[\mathrm{SrO}\right]+31.41\left[\mathrm{BaO}\right]-6.86\left[{\mathrm{Li}}_{2}O\right]+37.96\left[K_{2}O\right]+11.47\left[\mathrm{ZnO}\right]+25.83\left[{\mathrm{ZrO}}_2\right]+41.\left[{\mathrm{TiO}}_2\right]+12.32\left[Y_2{O}_3\right]-1.18\left[{\mathrm{Gd}}_2{O}_3\right]-1.18\left[{\mathrm{La}}_2{O}_3\right]+24.46\left[{\mathrm{Ta}}_2{O}_5\right]\right)/125.& \left(3\right)\end{array}$

6. The glass according to claim 1, which is used as a substrate.

7. The glass according to claim 6, which is used in manufacture of at least one of a fan out wafer level package or a fan out panel level package.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a schematic diagram of a glass according to the present embodiment; and

[0013] FIG. 2 is a schematic diagram for explaining a deflection evaluation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited by the embodiments, and in a case where there are a plurality of embodiments, the present invention includes a combination of the embodiments. In addition, the numerical value includes the range of rounding. Also, the numerical range represented by to means a numerical range including numerical values before and after to as a lower limit value and an upper limit value, and when to is used in the following description, the same meaning is given.

Glass

[0015] FIG. 1 is a schematic diagram of a glass according to the present embodiment. As illustrated in FIG. 1, the glass 10 according to the present embodiment is used as a glass substrate for manufacturing a semiconductor package, and more specifically, is a supporting glass substrate for manufacturing FOWLP or the like. However, the application of the glass 10 is not limited to the manufacture of FOWLP and the like and may be any application, and the glass 10 may be a glass substrate used for supporting a member or may be used for an application other than the support of a member. Note that FOWLP and the like encompass a fan out wafer level package (FOWLP) and a fan out panel level package (FOPLP).

(Composition of Glass)

[0016] Next, a preferred composition of the glass 10 will be described.

SiO.SUB.2

[0017] The glass 10 preferably contains SiO.sub.2 (the content of SiO.sub.2 is higher than 0 mol %). SiO.sub.2 is a component for decreasing the coefficient of linear thermal expansion and is a component for controlling the Young's modulus. In addition, in order to appropriately suppress increases in the melting temperature and the liquidus temperature, the content of SiO.sub.2 is preferably 60% or less. Further, SiO.sub.2 has an effect of improving the acid resistance and the sulfuric acid resistance of glass. In the glass 10, the content of SiO.sub.2 is preferably 40% or more and 60% or less, preferably 41% or more and 59% or less, preferably 42% or more and 58% or less, preferably 43% or more and 57% or less, preferably 43.5% or more and 56% or less, preferably 44% or more and 55% or less, preferably 44.5% or more and 54% or less, preferably 45% or more and 53% or less, preferably 45.5% or more and 52% or less, preferably 46% or more and 51.5% or less, preferably 46.5% or more and 51% or less, preferably 47% or more and 50.5% or less, preferably 47.5% or more and 50% or less, and more preferably 48% or more and 49.5% or less as expressed in mol % on an oxide basis. When the content of SiO.sub.2 falls within this range, manufacturing can be facilitated while deflection is suppressed. Note that the content herein refers to a ratio of the content to the entire glass 10 in terms of mol % on an oxide basis. That is, for example, the content of SiO.sub.2 of 40% or more and 60% or less means that the ratio of the content of SiO.sub.2 to the entire glass 10 in terms of mol % on an oxide basis is 40% or more and 60% or less.

B.sub.2O.sub.3

[0018] B.sub.2O.sub.3 has effects of suppressing devitrification due to crystallization of glass to facilitate manufacturing and controlling the Young's modulus. Thus, the glass 10 need not contain B.sub.2O.sub.3 (the content of B.sub.2O.sub.3 is 0 mol %), but may contain B.sub.203. In the glass 10, the content of B.sub.2O.sub.3 is preferably 0.01% or more and 15% or less, preferably 1% or more and 12% or less, preferably 2% or more and 10% or less, preferably 3% or more and 9% or less, preferably 4% or more and 8% or less, preferably 5% or more and 7% or less, and more preferably 5.5% or more and 6.5% or less as expressed in molo on an oxide basis. When the content of B.sub.2O.sub.3 falls within this range, manufacturing can be facilitated while deflection is suppressed.

Al.sub.2O.sub.3+Rare Earth Oxide

[0019] The glass 10 preferably contains at least one of Al.sub.2O.sub.3 or a rare earth oxide. The rare earth oxide herein may be one kind of rare earth oxide or a plurality of kinds of rare earth oxides. Containing Al.sub.2O.sub.3 and the rare earth oxide increases the Young's modulus. By not excessively reducing the total content of Al.sub.2O.sub.3 and the rare earth oxide, a decrease in the Young's modulus can be appropriately suppressed. In the glass 10, the total content of Al.sub.2O.sub.3 and the rare earth oxide (Al.sub.2O.sub.3+rare earth oxide) is preferably 0% or more and 20% or less, preferably 1% or more and 17% or less, preferably 3% or more and 16% or less, preferably 6% or more and 15% or less, preferably 7% or more and 14% or less, preferably 8% or more and 13% or less, preferably 9% or more and 12.5% or less, and more preferably 10% or more and 12% or less as expressed in mol % on an oxide basis. When the total content of Al.sub.2O.sub.3 and the rare earth oxide falls within this range, the liquidus temperature can be lowered, and thus manufacturing can be facilitated.

[0020] Note that the total content of Al.sub.2O.sub.3 and the rare earth oxide refers to the ratio of the total value of the content of Al.sub.2O.sub.3 and the content of the rare earth oxide to the entire glass 10. In addition, the glass 10 does not necessarily contain both Al.sub.2O.sub.3 and the rare earth oxide. For example, when the rare earth oxide is not contained, the total content of Al.sub.2O.sub.3 and the rare earth oxide refers to the content of Al.sub.2O.sub.3, and when the Al.sub.2O.sub.3 is not contained, it refers to the content of the rare earth oxide. When a plurality of kinds of rare earth oxides are contained, the content of the rare earth oxide refers to the total content of these rare earth oxides.

Parameter A

[0021] The ratio of the total content of Al.sub.2O.sub.3 and RO in the glass 10 to the total content of SiO.sub.2, Al.sub.2O.sub.3, and RO in the glass 10 (that is, (Al.sub.2O.sub.3+RO)/(SiO.sub.2+Al.sub.2O.sub.3+RO)) as expressed in mol % on an oxide basis is defined as the parameter A. The RO herein is the total content of divalent oxides. When a plurality of kinds of divalent oxides are contained, the total content of divalent oxides refers to the total content of these divalent oxides and when one kind of divalent oxide is contained, it refers to the content of the divalent oxide. The parameter A of the glass 10 is preferably 0.38 or more, preferably 0.39 or more and 0.5 or less, preferably 0.395 or more and 0.495 or less, preferably 0.4 or more and 0.49 or less, preferably 0.405 or more and 0.485 or less, preferably 0.41 or more and 0.48 or less, preferably 0.415 or more and 0.475 or less, preferably 0.42 or more and 0.47 or less, preferably 0.425 or more and 0.465 or less, preferably 0.43 or more and 0.46 or less, preferably 0.435 or more and 0.455 or less, and more preferably 0.44 or more and 0.45 or less. When the parameter A falls within this range, the melting temperature of the glass 10 can be lowered, and thus manufacturing can be facilitated.

[0022] Note that the glass 10 does not necessarily contain all of SiO.sub.2, Al.sub.2O.sub.3, and a divalent oxide. For example, when SiO.sub.2 is not contained, SiO.sub.2 in (SiO.sub.2+Al.sub.2O.sub.3+RO) is treated as zero. Similarly, when Al.sub.2O.sub.3 is not contained, Al.sub.2O.sub.3 in (Al.sub.2O.sub.3+RO) and (SiO.sub.2+Al.sub.2O.sub.3+RO) is treated as zero. Similarly, when no divalent oxide is contained, RO in (Al.sub.2O.sub.3+RO) and (SiO.sub.2+Al.sub.2O.sub.3+RO) is treated as zero.

Al.sub.2O.sub.3

[0023] Al.sub.2O.sub.3 has effects of increasing the Young's modulus to suppress deflection and suppressing phase separation of glass. Thus, the glass 10 need not contain Al.sub.2O.sub.3 (the content of Al.sub.2O.sub.3 is 0 mol %), but may contain Al.sub.2O.sub.3. In addition, by adjusting the content of Al.sub.2O.sub.3 to 20% or less, an increase in the liquidus temperature can be suppressed. In the glass 10, the content of Al.sub.2O.sub.3 is preferably 5% or more and 20% or less, preferably 6% or more and 18% or less, preferably 7% or more and 17% or less, preferably 8% or more and 16% or less, preferably 8.5% or more and 15% or less, preferably 9% or more and 14% or less, preferably 9.5% or more and 13% or less, preferably 10% or more and 12% or less, and more preferably 10.5% or more and 11% or less as expressed in mol % on an oxide basis. When the content of Al.sub.2O.sub.3 falls within this range, manufacturing can be facilitated while deflection is suppressed.

MgO

[0024] Since MgO increases the Young's modulus without increasing the density, deflection can be suppressed by increasing the specific modulus. In addition, there is also an effect of reducing the coefficient of linear thermal expansion. On the other hand, by adjusting the content of MgO to 30% or less, the liquidus temperature can be controlled to be low. Thus, the glass 10 need not contain MgO (the content of MgO is 0 mol %), but may contain MgO. In the glass 10, the content of MgO is preferably 1% or more and 30% or less, more preferably 5% or more and 29.5% or less, more preferably 9% or more and 29% or less, more preferably 10% or more and 28.5% or less, more preferably 11% or more and 28% or less, more preferably 12% or more and 27.5% or less, more preferably 13% or more and 27% or less, more preferably 14% or more and 26.5% or less, more preferably 15% or more and 26% or less, more preferably 16% or more and 25.5% or less, more preferably 17% or more and 25% or less, more preferably 18% or more and 24.5% or less, more preferably 19% or more and 24% or less, more preferably 19.5% or more and 23.5% or less, and more preferably 20% or more and 23% or less as expressed in mol % on an oxide basis. When the content of MgO falls within this range, manufacturing can be facilitated while deflection is suppressed.

Cao

[0025] CaO has characteristics of increasing the specific modulus next to MgO in the oxides of the group 2 elements, and not excessively decreasing the coefficient of linear thermal expansion, and further has a characteristic of being less likely to increase the liquidus temperature as compared with MgO. Thus, the glass 10 need not contain Cao (the content of Cao is 0 mol %), but may contain Cao. By adjusting the content of Cao to 10% or less, an increase in the coefficient of linear thermal expansion can be suppressed, and the liquidus temperature can be controlled to be low. In the glass 10, the content of Cao is preferably 0.01% or more and 10% or less, preferably 0.5% or more and 9% or less, preferably 1% or more and 8% or less, preferably 1.5% or more and 7% or less, preferably 1.65% or more and 6% or less, preferably 1.8% or more and 5% or less, and more preferably 2% or more and 4% or less as expressed in mol % on an oxide basis. In addition, the content of CaO may be 0.5% or more and 2% or less, or 1% or more and 1.5% or less. When the content of Cao falls within this range, manufacturing can be facilitated while deflection is suppressed.

SrO

[0026] SrO has effects of improving the meltability of glass and lowering the liquidus temperature. Thus, the glass 10 need not contain SrO (the content of SrO is 0 mol %), but may contain SrO. By adjusting the content of SrO to 10% or less, an increase in the coefficient of linear thermal expansion can be suppressed, and the liquidus temperature can be controlled to be low. In the glass 10, the content of SrO is preferably 0.01% or more and 10% or less, preferably 0.5% or more and 9% or less, preferably 1% or more and 8% or less, preferably 1.5% or more and 7% or less, preferably 1.65% or more and 6% or less, preferably 1.8% or more and 5% or less, and more preferably 2% or more and 4% or less as expressed in mol % on an oxide basis. In addition, the content of SrO may be 0.5% or more and 2% or less, or 1% or more and 1.5% or less. When the content of SrO falls within this range, manufacturing can be facilitated while deflection is suppressed.

BaO

[0027] BaO has effects of improving the meltability of glass and lowering the liquidus temperature. Thus, the glass 10 need not contain Bao (the content of Bao is 0 mol %), but may contain Bao. By adjusting the content of Bao to 10% or less, an increase in the coefficient of linear thermal expansion can be suppressed, and the liquidus temperature can be controlled to be low. In the glass 10, the content of BaO is preferably 0.01% or more and 10% or less, preferably 0.5% or more and 9% or less, preferably 1% or more and 8% or less, preferably 1.5% or more and 7% or less, preferably 1.65% or more and 6% or less, preferably 1.8% or more and 5% or less, and more preferably 2% or more and 4% or less as expressed in mol % on an oxide basis. In addition, the content of BaO may be 0.5% or more and 2% or less, or 1% or more and 1.5% or less. When the content of BaO falls within this range, manufacturing can be facilitated while deflection is suppressed.

[0028] In addition, by lowering the content of Bao, it is possible to suppress occurrence of cloudy defects on the surface caused when the glass is immersed in an acid. Thus, the glass 10 may contain BaO or need not contain BaO. In the glass 10, the content of Bao is preferably 10% or less, preferably 5% or less, preferably 3% or less, preferably 1% or less, preferably 0.8% or less, preferably 0.5% or less, more preferably 0.3% or less, and more preferably 0.1% or less as expressed in mol % on an oxide basis. When the content of BaO falls within this range, cloudy defects can be suppressed, and the sulfuric acid resistance of the glass can be improved.

Li.SUB.2.O

[0029] Among alkali metal oxides, Li.sub.2O has an effect of improving the meltability without decreasing the coefficient of linear thermal expansion. Thus, the glass 10 need not contain Li.sub.2O (the content of Li.sub.2O is 0 mol %), but may contain Li.sub.2O. By adjusting the content of Li.sub.2O to 5% or less, the Young's modulus can be increased, and an increase in the coefficient of linear thermal expansion can be suppressed. In the glass 10, the content of Li.sub.2O is preferably 0.01% or more and 5% or less, more preferably 0.1% or more and 4% or less, more preferably 0.15% or more and 3% or less, more preferably 0.2% or more and 2% or less, more preferably 0.25% or more and 1.5% or less, and more preferably 0.3% or more and 1% or less as expressed in mol % on an oxide basis. When the content of Li.sub.2O falls within this range, manufacturing can be facilitated while deflection is suppressed.

Na.SUB.2.O

[0030] Among alkali metal oxides, Na.sub.2O especially has effects of improving the meltability of glass and lowering the liquidus temperature. Thus, the glass 10 need not contain Na.sub.2O (the content of Na.sub.2O is 0 mol %), but may contain Na.sub.2O. By adjusting the content of Na.sub.2O to 5% or less, the Young's modulus can be increased, and an increase in the coefficient of linear thermal expansion can be suppressed. In the glass 10, the content of Na.sub.2O is preferably 0.01% or more and 5% or less, more preferably 0.1% or more and 4% or less, more preferably 0.15% or more and 3% or less, more preferably 0.2% or more and 2% or less, more preferably 0.25% or more and 1.5% or less, and more preferably 0.3% or more and 1% or less as expressed in mol % on an oxide basis. When the content of Na.sub.2O falls within this range, manufacturing can be facilitated while deflection is suppressed.

K.SUB.2.O

[0031] K.sub.2O has effects of improving the meltability of glass and lowering the liquidus temperature. Thus, the glass 10 need not contain K.sub.2O (the content of K.sub.2O is 0 mol %), but may contain K.sub.2O. By adjusting the content of K.sub.2O to 5% or less, the Young's modulus can be increased, and an increase in the coefficient of linear thermal expansion can be suppressed. In the glass 10, the content of K.sub.2O is preferably 0.01% or more and 5% or less, more preferably 0.1% or more and 4% or less, more preferably 0.15% or more and 3% or less, more preferably 0.2% or more and 2% or less, more preferably 0.25% or more and 1.5% or less, and more preferably 0.3% or more and 1% or less as expressed in mol % on an oxide basis. When the content of K.sub.2O falls within this range, manufacturing can be facilitated while deflection is suppressed.

[0032] The glass 10 may contain an alkali metal component, but preferably does not contain an alkali metal component. In the glass 10, the total content of alkali metal components is preferably 1% or less, more preferably 0.001% or more and 0.1% or less, more preferably 0.003% or more and 0.05% or less, and still more preferably 0.005% or more and 0.01% or less as expressed in mol % on an oxide basis. When the total content of the alkali metal components is small as described above, it is possible to suppress deterioration of properties of a metal or an oxide film provided on a glass surface in a manufacturing process of FOWLP or the like.

[0033] Note that the alkali metal component herein refers to a Group 1 metal such as Li, Na, K, or Rb or an oxide thereof contained in the glass 10.

ZnO

[0034] ZnO has effects of improving the meltability of glass and increasing the Young's modulus. Thus, the glass 10 need not contain ZnO (the content of ZnO is 0 mol %), but may contain ZnO. By adjusting the content of ZnO to 10% or less, an increase in the coefficient of linear thermal expansion can be suppressed, and the liquidus temperature can be controlled. In the glass 10, the content of ZnO is preferably 0.01% or more and 10% or less, more preferably 0.1% or more and 9% or less, more preferably 0.2% or more and 8% or less, more preferably 0.4% or more and 7% or less, more preferably 0.6% or more and 6% or less, more preferably 0.8% or more and 5% or less, and more preferably 1% or more and 4% or less as expressed in mol % on an oxide basis. When the content of ZnO falls within this range, manufacturing can be facilitated while deflection is suppressed.

P.sub.2O.sub.5

[0035] P.sub.2O.sub.5 has effects of improving the meltability of glass and lowering the coefficient of linear thermal expansion. Thus, the glass 10 need not contain P.sub.2O.sub.5 (the content of P.sub.2O.sub.5 is 0 mol %), but may contain P.sub.2O.sub.5. By adjusting the content of P.sub.2O.sub.5 to 5% or less, the Young's modulus can be increased without deteriorating the chemical resistance, and an increase in the coefficient of linear thermal expansion can be suppressed. In the glass 10, the content of P.sub.2O.sub.5 is preferably 0.01% or more and 5% or less, more preferably 0.1% or more and 4% or less, more preferably 0.15% or more and 3% or less, more preferably 0.2% or more and 2% or less, more preferably 0.25% or more and 1.5% or less, and more preferably 0.3% or more and 1% or less as expressed in molo on an oxide basis. When the content of P.sub.2O.sub.5 falls within this range, manufacturing can be facilitated while deflection is suppressed.

ZrO.SUB.2

[0036] ZrO.sub.2 can increase the Young's modulus without relatively decreasing the coefficient of linear thermal expansion. In addition, ZrO.sub.2 has an effect of improving the acid resistance and the sulfuric acid resistance of glass. Thus, the glass 10 need not contain ZrO.sub.2 (the content of ZrO.sub.2 is 0 mol %), but may contain ZrO.sub.2. By adjusting the content of ZrO.sub.2 to 10% or less, the liquidus temperature can be controlled. In the glass 10, the content of ZrO.sub.2 is preferably 0.01% or more and 10% or less, more preferably 0.2% or more and 7% or less, more preferably 0.5% or more and 4% or less, more preferably 0.7% or more and 4% or less, and more preferably 1% or more and 2% or less as expressed in mol % on an oxide basis. When the content of ZrO.sub.2 falls within this range, manufacturing can be facilitated while deflection is suppressed.

TiO.SUB.2

[0037] TiO.sub.2 can increase the Young's modulus without relatively decreasing the coefficient of linear thermal expansion. In addition, TiO.sub.2 has an effect of improving the acid resistance and the sulfuric acid resistance of glass. Thus, the glass 10 need not contain TiO.sub.2 (the content of TiO.sub.2 is 0 mol %), but may contain TiO.sub.2. By adjusting the content of TiO.sub.2 to 10% or less, the liquidus temperature can be controlled. In the glass 10, the content of TiO.sub.2 is preferably 0.01% or more and 10% or less, more preferably 0.2% or more and 7% or less, more preferably 0.5% or more and 4% or less, more preferably 0.7% or more and 4% or less, and more preferably 1% or more and 2% or less as expressed in mol % on an oxide basis. When the content of TiO.sub.2 falls within this range, manufacturing can be facilitated while deflection is suppressed.

Y.sub.2O.sub.3

[0038] Y.sub.2O.sub.3 has effects of improving the meltability of glass and increasing the Young's modulus. Thus, the glass 10 need not contain Y.sub.2O.sub.3 (the content of Y.sub.2O.sub.3 is 0 mol %), but may contain Y.sub.2O.sub.3. By adjusting the content of Y.sub.2O.sub.3 to 7% or less, the coefficient of linear thermal expansion can be controlled. In the glass 10, the content of Y.sub.2O.sub.3 is preferably 0.1% or more and 7% or less, more preferably 0.7% or more and 6% or less, more preferably 1% or more and 5% or less, more preferably 1.5% or more and 4% or less, and more preferably 2% or more and 3% or less as expressed in mol % on an oxide basis. When the content of Y.sub.2O.sub.3 falls within this range, manufacturing can be facilitated while deflection is suppressed.

Gd.sub.2O.sub.3

[0039] Gd.sub.2O.sub.3 has effects of improving the meltability of glass and increasing the Young's modulus. Thus, the glass 10 need not contain Gd.sub.2O.sub.3 (the content of Gd.sub.2O.sub.3 is 0 mol %), but may contain Gd.sub.2O.sub.3. By adjusting the content of Gd.sub.2O.sub.3 to 7% or less, the coefficient of linear thermal expansion can be controlled. In the glass 10, the content of Gd.sub.2O.sub.3 is preferably 0.1% or more and 7% or less, more preferably 0.7% or more and 6% or less, more preferably 1% or more and 5% or less, more preferably 1.5% or more and 4% or less, and more preferably 2% or more and 3% or less as expressed in molo on an oxide basis. When the content of Gd.sub.2O.sub.3 falls within this range, manufacturing can be facilitated while deflection is suppressed.

La.sub.2O.sub.3

[0040] La.sub.2O.sub.3 has effects of improving the meltability of glass and increasing the Young's modulus. Thus, the glass 10 need not contain La.sub.2O.sub.3 (the content of La.sub.2O.sub.3 is 0 mol %), but may contain La.sub.2O.sub.3. By adjusting the content of La.sub.2O.sub.3 to 7% or less, the coefficient of linear thermal expansion can be controlled. In the glass 10, the content of La.sub.2O.sub.3 is preferably 0.1% or more and 7% or less, more preferably 0.7% or more and 6% or less, more preferably 1% or more and 5% or less, more preferably 1.5% or more and 4% or less, and more preferably 2% or more and 3% or less as expressed in mol % on an oxide basis. When the content of La.sub.2O.sub.3 falls within this range, manufacturing can be facilitated while deflection is suppressed.

WO.SUB.3

[0041] WO.sub.3 has effects of improving the meltability of glass and increasing the Young's modulus. Thus, the glass 10 need not contain WO.sub.3 (the content of WO.sub.3 is 0 mol %), but may contain WO.sub.3. By adjusting the content of WO.sub.3 to 7% or less, an increase in the coefficient of linear thermal expansion can be suppressed, and the liquidus temperature can be controlled. In the glass 10, the content of WO.sub.3 is preferably 0.1% or more and 7% or less, more preferably 0.3% or more and 5% or less, more preferably 0.5% or more and 3% or less, more preferably 0.8% or more and 2.5% or less, and more preferably 1% or more and 2% or less as expressed in mol % on an oxide basis. When the content of WO.sub.3 falls within this range, manufacturing can be facilitated while deflection is suppressed.

Ta.sub.2O.sub.5

[0042] Ta.sub.2O.sub.5 has effects of decreasing the coefficient of linear thermal expansion and increasing the Young's modulus. In addition, Ta.sub.2O.sub.5 has an effect of improving the acid resistance and the sulfuric acid resistance of glass. Thus, the glass 10 need not contain Ta.sub.2O.sub.5 (the content of Ta.sub.2O.sub.5 is 0 mol %), but may contain Ta.sub.2O.sub.5. By adjusting the content of Ta.sub.2O.sub.5 to 10% or less, the liquidus temperature can be controlled. In the glass 10, the content of Ta.sub.2O.sub.5 is preferably 0.1% or more and 10% or less, more preferably 0.5% or more and 5% or less, more preferably 1% or more and 4% or less, more preferably 1.5% or more and 3.5% or less, and more preferably 2% or more and 3% or less as expressed in mol % on an oxide basis. When the content of Ta.sub.2O.sub.5 falls within this range, manufacturing can be facilitated while deflection is suppressed.

MnO

[0043] MnO has an effect of increasing the Young's modulus. However, MnO may increase the liquidus temperature, and even a small amount of MnO causes the glass to be colored from dark brown to black. Thus, it is preferable that the glass 10 does not contain MnO. In the glass 10, the content of MnO is preferably 5% or less, preferably 3% or less, preferably 0.1% or less, more preferably 0.001% or more and 0.05% or less, and still more preferably 0.005% or more and 0.01% or less as expressed in mol % on an oxide basis. When the content of MnO falls within this range, a decrease in the light transmittance can be suppressed.

PbO

[0044] PbO has an effect of increasing the Young's modulus, but is an oxide having a high environmental load. Thus, it is preferable that the glass 10 does not contain PbO. In the glass 10, the content of PbO is preferably 0.1% or less, more preferably 0.05% or less, and still more preferably 0.01% or less as expressed in mol % on an oxide basis. When the content of PbO falls within this range, the environmental load can be suppressed.

Fe.sub.2O.sub.3

[0045] The glass 10 preferably does not contain Fe.sub.2O.sub.3. In the glass 10, the content of Fe.sub.2O.sub.3 in outer percentage is preferably 0.1% or less, more preferably 0.001% or more and 0.05% or less, and still more preferably 0.005% or more and 0.01% or less as expressed in mass % on an oxide basis. When the content of Fe.sub.2O.sub.3 is low as described above, a decrease in the light transmittance can be suppressed.

[0046] Note that the content of Fe.sub.2O.sub.3 in outer percentage refers to the ratio of the mass of Fe.sub.2O.sub.3 contained in the glass 10 to the total value of the mass of all the components of the glass 10 excluding Fe.sub.2O.sub.3 on an oxide basis.

Y.sub.2O.sub.3+Gd.sub.2O.sub.3+La.sub.2O.sub.3+Nd.sub.2O.sub.3+Ta.sub.2O.sub.5+Nb.sub.2O.sub.5

[0047] In the glass 10, the total content of Y.sub.2O.sub.3, Gd.sub.2O.sub.3, La.sub.2O.sub.3, Nd.sub.2O.sub.3, Ta.sub.2O.sub.5, and Nb.sub.2O.sub.5 (Y.sub.2O.sub.3+Gd.sub.203+Ta.sub.2O.sub.5+La.sub.2O.sub.3+Nd.sub.2O.sub.3+Nb.sub.2O.sub.5) is preferably 0.5% or more, more preferably 1% or more and 10% or less, more preferably 2% or more and 8% or less, more preferably 3% or more and 7% or less, and more preferably 4% or more and 6% or less as expressed in mol % on an oxide basis. The total content of these components may be 1% or more and 4% or less, or 1.5% or more and 2% or less. When the total content of these components falls within this range, manufacturing can be facilitated while deflection is suppressed.

[0048] Note that the glass 10 need not contain all of the above components, and may include only some of the components. In addition, the glass 10 may contain none of the above components. That is, for example, when Y.sub.2O.sub.3 is not contained, (Y.sub.2O.sub.3) in (Y.sub.2O.sub.3+Gd.sub.2O.sub.3+Ta.sub.2O.sub.5+La.sub.2O.sub.3+Nd.sub.2O.sub.3+Nb.sub.2O.sub.5) is treated as zero, and the same applies to a case where other components are not contained.

(Al.sub.2O.sub.3+MgO)/(SiO.sub.2+Al.sub.2O.sub.3+B.sub.2O.sub.3+MgO)

[0049] In the glass 10, the ratio of the total content of Al.sub.2O.sub.3 and MgO to the total content of SiO.sub.2, Al.sub.2O.sub.3, B.sub.2O.sub.3, and MgO (that is, (Al.sub.2O.sub.3+MgO)/(SiO.sub.2+Al.sub.2O.sub.3+B.sub.2O.sub.3+MgO)) as expressed in mol % on an oxide basis is preferably 0.1 or more and 1 or less, more preferably 0.26 or more and 0.48 or less, more preferably 0.28 or more and 0.46 or less, more preferably 0.3 or more and 0.44 or less, more preferably 0.32 or more and 0.42 or less, and more preferably 0.34 or more and 0.4 or less. When the total content of these components falls within this range, the Young's modulus can be increased to suppress deflection.

[0050] Note that the glass 10 does not necessarily contain all of SiO.sub.2, Al.sub.2O.sub.3, B.sub.2O.sub.3, and MgO. That is, for example, when Al.sub.2O.sub.3 is not contained, (Al.sub.2O.sub.3) in (Al.sub.2O.sub.3+MgO) and (SiO.sub.2+Al.sub.2O.sub.3+B.sub.2O.sub.3+MgO) is treated as zero, and the same applies to a case where other components are not contained.

MgO/RO

[0051] In the glass 10, the ratio of the content of MgO to the total content of divalent oxides (RO), (MgO/RO) as expressed in mol % on an oxide basis is preferably 0.3 or more and 1 or less, more preferably 0.4 or more and 0.9 or less, more preferably 0.45 or more and 0.875 or less, more preferably 0.5 or more and 0.85 or less, more preferably 0.55 or more and 0.825 or less, and more preferably 0.6 or more and 0.8 or less. In addition, the ratio may be 0.75% or more and 0.95% or less, or 0.8% or more and 0.9% or less. When the total content of these components falls within this range, the coefficient of linear thermal expansion can be lowered to suppress deflection.

[0052] Note that the glass 10 does not necessarily contain divalent oxides such as MgO. For example, when MgO is not contained, MgO in (MgO/RO) is treated as zero, and when divalent oxides other than MgO are not contained, the content of the divalent oxides other than MgO in (MgO/RO) is treated as zero.

Value of N

[0053] In the glass 10, the number of oxides present in a content of 0.5% or more, among oxides contained in the glass 10, represented by N, is preferably 5 or more, more preferably 7 or more, more preferably 8 or more, more preferably 9 or more, and more preferably 10 or more. When the number of N is high as described above, the liquidus temperature can be lowered, and thus manufacturing can be facilitated.

[0054] Note that the glass 10 preferably does not contain a sintered body. That is, the glass 10 is preferably a glass that is not a sintered body. Here, the sintered body refers to a member in which a plurality of particles are heated at a temperature lower than the melting point to bond the particles. The porosity of the sintered body is high to some extent because the sintered body includes voids, but the porosity of the glass 10 is low, and is usually 0% because the glass is not a sintered body. However, it is allowable to include an inevitable very small amount of pores. The porosity herein is a so-called true porosity, and refers to a value obtained by dividing a sum of volumes of pores (voids) communicating with the outside and pores (voids) not communicating with the outside by a total volume (apparent volume). The porosity can be measured according to, for example, JIS R 1634:1998 Test methods for density and apparent porosity of fine ceramics.

[0055] In addition, it is preferable that a glass used for the glass 10 is usually an amorphous glass, that is, an amorphous solid. Also, this glass may be a crystallized glass containing crystals on the surface or inside, but an amorphous glass is preferable from the viewpoint of density. Among ceramics, those produced by a sintering method are preferably not used because they have a low transmittance and a high density.

Shape of Glass

[0056] Next, the shape of the glass 10 will be described. As illustrated in FIG. 1, the glass 10 is a plate-like glass substrate including a surface 12 which is a principal surface on one side and a surface 14 which is a principal surface opposite to the surface 12. The surface 14 may be, for example, parallel to the surface 12. The glass 10 may have a disk shape that is circular in plan view, that is, when viewed from a direction orthogonal to the surface 12, but the glass is not limited to the disk shape and may have any shape, and may be a plate of a polygonal shape such as a rectangle. Note that examples of the shape also include shapes in which a cut-out such as a notch or an orientation flat is provided on the outer periphery.

[0057] In addition, the thickness D of the glass 10, that is, the length between the surface 12 and the surface 14 is preferably 0.1 mm or more and 5.0 mm or less, more preferably 0.1 mm or more and 2.0 mm or less, and still more preferably 0.1 mm or more and 0.5 mm or more. By adjusting the thickness D to 0.1 mm or more, it is possible to prevent the glass 10 from becoming too thin and to suppress breakage due to deflection or impact. By adjusting the thickness D to 2.0 mm or less, it is possible to suppress the weight, and by adjusting the thickness D to 0.5 mm or less, it is possible to more suitably suppress the weight.

Properties of Glass

[0058] Next, properties of the glass 10 will be described.

Young's Modulus

[0059] The Young's modulus E of the glass 10 is preferably 80 GPa or more, more preferably 85 GPa or more and 180 GPa or less, more preferably 88 GPa or more and 170 GPa or less, more preferably 90 GPa or more and 160 GPa or less, more preferably 93 GPa or more and 150 GPa or less, more preferably 95 GPa or more and 145 GPa or less, more preferably 97 GPa or more and 140 GPa or less, more preferably 98 GPa or more and 135 GPa or less, and still more preferably 99 GPa or more and 130 GPa or less. By setting the Young's modulus E within this range, deflection can be appropriately suppressed. When the Young's modulus is too high, cutting, grinding, and polishing processing become difficult.

Young's Modulus Parameter

[0060] The Young's modulus parameter Y of the glass 10 calculated from the composition is preferably 0.8 or more, more preferably 0.85 or more and 1.8 or less, more preferably 0.88 or more and 1.7 or less, more preferably 0.9 or more and 1.6 or less, more preferably 0.93 or more and 1.5 or less, more preferably 0.95 or more and 1.45 or less, more preferably 0.97 or more and 1.4 or less, more preferably 0.98 or more and 1.35 or less, and still more preferably 0.99 or more and 1.3 or less. By setting the Young's modulus parameter within this range, deflection can be appropriately suppressed.

[0061] The Young's modulus parameter Y is calculated from Formula (1).

[00001]$\begin{array}{cc}Y=\left(123-0.54\left[{\mathrm{SiO}}_2\right]+0.3\left[{\mathrm{Al}}_2{O}_3\right]-1.15\left[B_2{O}_3\right]+0.21\left[\mathrm{MgO}\right]-0.2\left[\mathrm{CaO}\right]-0.1\left[\mathrm{SrO}\right]-1.2\left[\mathrm{BaO}\right]+\left[{\mathrm{Li}}_{2}O\right]-2.8\left[K_{2}O\right]+0.05\left[\mathrm{ZnO}\right]+1.46\left[{\mathrm{ZrO}}_2\right]-0.05\left[{\mathrm{TiO}}_2\right]+1.6\left[Y_2{O}_3\right]+1.35\left[{\mathrm{Gd}}_2{O}_3\right]+1.37\left[{\mathrm{La}}_2{O}_3\right]+\left[{\mathrm{Ta}}_2{O}_5\right]\right)/100& \left(1\right)\end{array}$

[0062] Note that the content of the oxide R.sub.xO.sub.y (R is an element constituting the oxide, and x and y are any suitable integers) contained in the glass 10 in terms of mol % on an oxide basis is represented by [R.sub.xO.sub.y]. The content herein refers to the ratio of the content of the oxide R.sub.xO.sub.y to the entire glass 10 in terms of mol % on an oxide basis. That is, for example, [SiO.sub.2] in Formula (1) refers to the ratio of the content of SiO.sub.2 to the entire glass 10 in terms of mol % on an oxide basis.

[0063] The glass 10 need not contain all the oxides shown in Formula (1). In Formula (1), the content of the oxide not contained in the glass 10 is treated as zero. In addition, the glass 10 may contain a component other than the oxides shown in Formula (1).

Coefficient of Linear Thermal Expansion

[0064] The coefficient of linear thermal expansion of the glass 10 is preferably 6 ppm/ C. or less, more preferably 3 ppm/ C. or more and 5.9 ppm/ C. or less, more preferably 3.5 ppm/ C. or more and 5.8 ppm/ C. or less, more preferably 4 ppm/ C. or more and 5.7 ppm/ C. or less, more preferably 4.2 ppm/ C. or more and 5.6 ppm/ C. or less, more preferably 4.4 ppm/ C. or more and 5.5 ppm/ C. or less, more preferably 4.6 ppm/ C. or more and 5.4 ppm/ C. or less, and still more preferably 4.8 ppm/ C. or more and 5.3 ppm/ C. or less.

[0065] The coefficient of linear thermal expansion of the glass 10 may also be in the following range. The coefficient of linear thermal expansion of the glass 10 is preferably 6.5 ppm/ C. or less, more preferably 3 ppm/ C. or more and 6.4 ppm/ C. or less, more preferably 3.5 ppm/ C. or more and 6.3 ppm/ C. or less, more preferably 4 ppm/ C. or more and 6.2 ppm/ C. or less, more preferably 4.5 ppm/ C. or more and 6.1 ppm/ C. or less, more preferably 5 ppm/ C. or more and 6 ppm/ C. or less, more preferably 5.5 ppm/ C. or more and 5.9 ppm/ C. or less, more preferably 5.6 ppm/ C. or more and 5.85 ppm/ C. or less, and still more preferably 5.7 ppm/ C. or more and 5.8 ppm/ C. or less.

[0066] In addition, the coefficient of linear thermal expansion of the glass 10 may be in the following range. The coefficient of linear thermal expansion of the glass 10 is preferably 5.0 ppm/ C. or less, more preferably 3.6 ppm/ C. or more and 4.9 ppm/ C. or less, more preferably 3.7 ppm/ C. or more and 4.8 ppm/ C. or less, more preferably 3.8 ppm/ C. or more and 4.7 ppm/ C. or less, more preferably 3.85 ppm/ C. or more and 4.65 ppm/ C. or less, more preferably 3.9 ppm/ C. or more and 4.6 ppm/ C. or less, more preferably 3.95 ppm/ C. or more and 4.55 ppm/ C. or less, more preferably 4 ppm/ C. or more and 4.5 ppm/ C. or less, more preferably 4.1 ppm/ C. or more and 4.45 ppm/ C. or less, and still more preferably 4.2 ppm/ C. or more and 4.4 ppm/ C. or less.

[0067] By setting the coefficient of linear thermal expansion within this range, deflection can be appropriately suppressed. The coefficient of linear thermal expansion is an average coefficient of thermal expansion in the range of 50 C. to 200 C., and is a value measured in accordance with DIN-51045-1 as a standard for thermal expansion measurement. For example, measurement is performed in the range of 30 C. to 300 C. using a dilatometer DIL 402 Expedis Supreme) manufactured by NETZSCH as a measuring apparatus, and an average coefficient of thermal expansion in the range of 50 C. to 200 C. may be employed as the coefficient of linear thermal expansion.

Thermal Expansion Parameter

[0068] The thermal expansion parameter C of the glass 10 calculated from the composition is preferably 1.2 or less, more preferably 0.6 or more and 1.18 or less, more preferably 0.7 or more and 1.16 or less, more preferably 0.8 or more and 1.14 or less, more preferably 0.84 or more and 1.12 or less, more preferably 0.88 or more and 1.1 or less, more preferably 0.92 or more and 1.08 or less, and still more preferably 0.96 or more and 1.06 or less.

[0069] The thermal expansion parameter C of the glass 10 may also be in the following range. The thermal expansion parameter C is preferably 1.3 or less, more preferably 0.6 or more and 1.28 or less, more preferably 0.7 or more and 1.26 or less, more preferably 0.8 or more and 1.24 or less, more preferably 0.9 or more and 1.22 or less, more preferably 1 or more and 1.2 or less, more preferably 1.1 or more and 1.18 or less, more preferably 1.12 or more and 1.17 or less, and still more preferably 1.14 or more and 1.16 or less.

[0070] In addition, the thermal expansion parameter C of the glass 10 may be in the following range. The thermal expansion parameter C is preferably 1.0 or less, more preferably 0.72 or more and 0.98 or less, more preferably 0.74 or more and 0.96 or less, more preferably 0.76 or more and 0.94 or less, more preferably 0.77 or more and 0.93 or less, more preferably 0.78 or more and 0.92 or less, more preferably 0.79 or more and 0.91 or less, more preferably 0.8 or more and 0.9 or less, more preferably 0.82 or more and 0.89 or less, and still more preferably 0.84 or more and 0.88 or less.

[0071] By setting the thermal expansion parameter C within this range, the coefficient of linear thermal expansion can be kept low, and deflection can be appropriately suppressed.

[0072] The thermal expansion parameter C is calculated from Formula (2).

[00002]$\begin{array}{cc}C=\left(14.098-0.1245\left[{\mathrm{SiO}}_2\right]-0.131\left[{\mathrm{Al}}_2{O}_3\right]-0.101\left[B_2{O}_3\right]-0.051\left[\mathrm{MgO}\right]+0.013\left[\mathrm{CaO}\right]+0.53\left[\mathrm{SrO}\right]+0.018\left[\mathrm{BaO}\right]+0.041\left[{\mathrm{Li}}_{2}O\right]+0.395\left[{\mathrm{Na}}_{2}O\right]-0.066\left[\mathrm{ZnO}\right]-0.033\left[{\mathrm{ZrO}}_2\right]-0.072\left[{\mathrm{TiO}}_2\right]+0.035\left[Y_2{O}_3\right]+0.074\left[{\mathrm{Gd}}_2{O}_3\right]+0.074\left[{\mathrm{La}}_2{O}_3\right]-0.091\left[{\mathrm{Ta}}_2{O}_5\right]\right)/5& \left(2\right)\end{array}$

[0073] The glass 10 need not contain all the oxides shown in Formula (2). In Formula (2), the content of the oxide not contained in the glass 10 is treated as zero. In addition, the glass 10 may contain a component other than the oxides shown in Formula (2).

Liquidus Temperature

[0074] The liquidus temperature T.sub.L of the glass 10 is preferably 1300 C. or lower, more preferably 800 C. or higher and 1290 C. or lower, more preferably 825 C. or higher and 1280 C. or lower, more preferably 850 C. or higher and 1270 C. or lower, more preferably 875 C. or higher and 1260 C. or lower, more preferably 900 C. or higher and 1250 C. or lower, more preferably 925 C. or higher and 1240 C. or lower, more preferably 950 C. or higher and 1230 C. or lower, more preferably 975 C. or higher and 1220 C. or lower, more preferably 1000 C. or higher and 1210 C. or lower, and still more preferably 1200 C. or lower. By setting the liquidus temperature within this range, manufacturing can be facilitated. The liquidus temperature can be evaluated by placing glass particles, which pass through a sieve with a mesh width of 4.0 mm and do not pass through a sieve with a mesh width of 2.3 mm, on a platinum dish, then holding the glass particles for 1 hour in an electric furnace set at a predetermined temperature, and measuring the temperature at which crystals are precipitated.

Liquidus Parameter

[0075] The liquidus parameter L of the glass 10 calculated from the composition is preferably 10.5 or less, more preferably 6.4 or more and 10.4 or less, more preferably 7.2 or more and 10.3 or less, more preferably 7.6 or more and 10.2 or less, more preferably 7.7 or more and 10.1 or less, more preferably 7.8 or more and 10 or less, more preferably 7.9 or more and 9.9 or less, and still more preferably 8 or more and 9.8 or less. is still more preferred. By setting the liquidus parameter L within this range, the liquidus temperature can be kept low, and thus manufacturing can be facilitated.

[0076] The liquidus parameter L is calculated from Formula (3).

[00003]$\begin{array}{cc}L=\left(-642.5+20.6\left[{\mathrm{SiO}}_2\right]+31.9\left[{\mathrm{Al}}_2{O}_3\right]+2.85\left[B_2{O}_3\right]+11.24\left[\mathrm{MgO}\right]+17.3\left[\mathrm{CaO}\right]+1.75\left[\mathrm{SrO}\right]+31.41\left[\mathrm{BaO}\right]-6.86\left[{\mathrm{Li}}_{2}O\right]+37.96\left[K_{2}O\right]+11.47\left[\mathrm{ZnO}\right]+25.83\left[{\mathrm{ZrO}}_2\right]+41.\left[{\mathrm{TiO}}_2\right]+12.32\left[Y_2{O}_3\right]-1.18\left[{\mathrm{Gd}}_2{O}_3\right]-1.18\left[{\mathrm{La}}_2{O}_3\right]+24.46\left[{\mathrm{Ta}}_2{O}_5\right]\right)/125& \left(3\right)\end{array}$

[0077] The glass 10 need not contain all the oxides shown in Formula (3). In Formula (3), the content of the oxide not contained in the glass 10 is treated as zero. In addition, the glass 10 may contain a component other than the oxides shown in Formula (3).

Melting Temperature T.sub.2, Working Temperature T.sub.3, Molding Temperature T.sub.4

[0078] The melting temperature T.sub.2 of the glass 10 is preferably 1000 C. or higher and 1550 C. or lower, more preferably 1100 C. or higher and 1500 C. or lower, more preferably 1150 C. or higher and 1450 C. or lower, more preferably 1200 C. or higher and 1400 C. or lower, and more preferably 1250 C. or higher and 1350 C. or lower. The melting temperature T.sub.2 refers to a temperature at which the viscosity n is 102 dPa.Math.s. When the melting temperature T.sub.2 is relatively low as described above, melting can be facilitated.

[0079] The working temperature T.sub.3 of the glass 10 is preferably 1000 C. or higher and 1400 C. or lower, more preferably 1050 C. or higher and 1350 C. or lower, more preferably 1080 C. or higher and 1300 C. or lower, more preferably 1100 C. or higher and 1250 C. or lower, and more preferably 1130 C. or higher and 1200 C. or lower. The working temperature T.sub.3 refers to a temperature at which the viscosity n is 103 dPa.Math.s. When the working temperature T.sub.3 is relatively low as described above, molding can be easily performed.

[0080] The molding temperature T.sub.4 of the glass 10 is preferably 900 C. or higher and 1250 C. or lower, more preferably 950 C. or higher and 1200 C. or lower, more preferably 1000 C. or higher and 1150 C. or lower, and more preferably 1030 C. or higher and 1100 C. or lower. The molding temperature T.sub.4 refers to a temperature at which the viscosity is 104 dPa.Math.s. When the molding temperature T.sub.4 is relatively low as described above, molding can be easily performed.

[0081] Note that the melting temperature T.sub.2, the working temperature T.sub.3, and the molding temperature T.sub.4 can be measured by an inner cylinder rotation method or the like.

Glass Transition Temperature

[0082] The glass transition temperature of the glass 10 is preferably 600 C. or higher and 850 C. or lower, more preferably 620 C. or higher and 800 C. or lower, more preferably 640 C. or higher and 780 C. or lower, more preferably 660 C. or higher and 760 C. or lower, more preferably 680 C. or higher and 740 C. or lower, more preferably 690 C. or higher and 730 C. or lower, and still more preferably 695 C. or higher and 720 C. or lower. The glass transition temperature can be measured in accordance with the method defined in JIS R3103-3:2001 Viscosity and viscometric fixed temperature of glass-Part 3: Determination of dilatometric transformation temperature.

Density

[0083] The density of the glass 10 is preferably 2.6 g/cm.sup.3 or more and 3.6 g/cm.sup.3 or less, more preferably 2.7 g/cm.sup.3 or more and 3.4 g/cm.sup.3 or less, more preferably 2.75 g/cm.sup.3 or more and 3.35 g/cm.sup.3 or less, more preferably 2.8 g/cm.sup.3 or more and 3.3 g/cm.sup.3 or less, more preferably 2.85 g/cm.sup.3 or more and 3.25 g/cm.sup.3 or less, and still more preferably 2.9 g/cm.sup.3 or more and 3.2 g/cm.sup.3 or less.

Liquidus Viscosity

[0084] The liquidus viscosity log .sub.L (dPa.Math.s) of the glass 10 is preferably 2 or more and 7 or less, more preferably 2.2 or more and 6.5 or less, more preferably 2.4 or more and 6 or less, more preferably 2.6 or more and 5.5 or less, more preferably 2.8 or more and 5 or less, more preferably 2.9 or more and 4.5 or less, and more preferably 3 or more and 4.2 or less. The liquidus viscosity refers to the viscosity of the glass 10 at the liquidus temperature. When the liquidus viscosity is relatively high as described above, manufacturing can be facilitated. Note that the liquidus viscosity can be determined by measuring a temperature-viscosity curve according to an inner cylinder rotation method or the like and calculating the viscosity at the liquidus temperature.

Fracture Toughness Value

[0085] The fracture toughness value K.sub.IC of the glass 10 is preferably 0.5 MPa.Math.m.sup.0.5 or more and 2 MPa.Math.m.sup.0.5 or less, more preferably 0.7 MPa.Math.m.sup.0.5 or more and 1.5 MPa.Math.m.sup.0.5 or less, more preferably 0.8 MPa.Math.m.sup.0.5 or more and 1.4 MPa.Math.m.sup.0.5 or less, and still more preferably 0.9 MPa.Math.m.sup.0.5 or more and 1.3 MPa.Math.m.sup.0.5 or less. When the fracture toughness value K.sub.IC falls within this range, breakage of the glass 10 can be suppressed. Note that the fracture toughness value K.sub.IC can be measured using a single-edge-precracked-beam method (SEPB method) as defined in, for example, JIS R1607:2015 Testing methods for fracture toughness of fine ceramics at room temperature.

Transmittance of Light

[0086] The internal transmittance for light with a wavelength of 308 nm (ultraviolet ray) through the glass 10 having a thickness D of 0.7 mm is preferably 30% or more, more preferably 35% or more, still more preferably 40% or more, still more preferably 45% or more, still more preferably 50% or more, still more preferably 55% or more, and still more preferably 60% or more. When the transmittance for light with a wavelength of 308 nm falls within this range, ultraviolet rays can be appropriately transmitted.

[0087] The internal transmittance for light with a wavelength of 350 nm (ultraviolet ray) through the glass 10 having a thickness D of 0.7 mm is preferably 30% or more, more preferably 40% or more, still more preferably 50% or more, still more preferably 60% or more, still more preferably 70% or more, still more preferably 75% or more, and still more preferably 77% or more. When the transmittance for light with a wavelength of 350 nm falls within this range, ultraviolet rays can be appropriately transmitted.

[0088] The internal transmittance for light with a wavelength of 550 nm (visible light) through the glass 10 having a thickness D of 0.7 mm is preferably 70% or more, more preferably 75% or more, still more preferably 80% or more, still more preferably 85% or more, still more preferably 86% or more, still more preferably 87% or more, and still more preferably 88% or more. When the transmittance for light with a wavelength of 550 nm falls within this range, visible light can be appropriately transmitted.

[0089] The internal transmittance for light with a wavelength of 1064 nm (infrared ray) through the glass 10 having a thickness D of 0.7 mm is preferably 80% or more, more preferably 85% or more, and more preferably 90% or more. When the transmittance for light with a wavelength of 1064 nm falls within this range, infrared rays can be appropriately transmitted.

[0090] Note that the transmittance can be measured by measuring a spectral transmittance curve with a spectrophotometer or the like.

Sulfuric Acid Resistance

[0091] The amount of weight change (amount of weight loss) at the time of exposure of the glass 10 to acid (sulfuric acid) is preferably 0.20 mg/cm.sup.2 or less, preferably 0.10 mg/cm.sup.2 or less, preferably 0.050 mg/cm.sup.2 or less, preferably 0.030 mg/cm.sup.2 or less, preferably 0.020 mg/cm.sup.2 or less, preferably 0.015 mg/cm.sup.2 or less, preferably 0.010 mg/cm.sup.2 or less, preferably 0.008 mg/cm.sup.2 or less, preferably 0.005 mg/cm.sup.2 or less, and more preferably 0.003 mg/cm.sup.2 or less. When the amount of weight change at the time of exposure of the glass 10 to acid is small as described above, the glass 10 can be used in an acid environment. In addition, it can be repeatedly used in the acid treatment step. The amount of weight change at the time of exposure to acid refers to a value obtained by dividing the absolute value of the difference between the weight of the glass 10 after exposure to acid and the weight of the glass 10 before exposure to acid by the surface area of the glass 10 before exposure to acid. The conditions for exposure to acid may be any conditions, but in this case, the glass 10 is immersed in sulfuric acid (H.sub.2SO.sub.4) having a pH of 2 and a temperature of 40 C. for 2 hours.

[0092] In addition, it is preferable that the glass 10 has no change in the light transmission ability of the glass 10 before exposure to acid and after exposure to acid. In the determination of a change in the transmission ability after exposure to acid, at the time of visual observation, a case where no cloudy portion was observed on the surface was evaluated as (no change in the transmission ability), and a case where a cloudy portion was observed was evaluated as (change in the transmission ability). When the change in the transmission ability at the time of exposure of the glass 10 to acid is small as described above, the glass 10 can be used in an acid environment. In addition, it can be repeatedly used in the acid treatment step.

[0093] The state before exposure to acid refers to a state after the glass 10 is weighed and before it is exposed to acid. Then, the state after exposure to acid refers to a state after the glass 10 is weighed and exposed to acid. The conditions for exposure to acid may be any conditions, but in this case, the glass 10 is immersed in sulfuric acid (H.sub.2SO.sub.4) having a pH of 2 and a temperature of 40 C. for 2 hours.

[0094] As described above, the glass 10 according to the present embodiment preferably has high sulfuric acid resistance. When the sulfuric acid resistance of the glass 10 is high, there is an effect that makes the light transmission ability less likely to be impaired even after the glass 10 is exposed to sulfuric acid. In addition, when the sulfuric acid resistance of the glass is high, it is possible to suppress surface deposits at the time of exposure to sulfuric acid. When the glass subjected to the process including sulfuric acid immersion is introduced into the subsequent process, the surface deposits may contaminate the process. By suppressing the surface deposits, it is possible to suppress process contamination.

Sulfuric Acid Resistance Parameter

[0095] The sulfuric acid resistance parameter S of the glass 10 calculated from the BaO content and the amount of weight change at the time of exposure to acid is preferably 3 or less, more preferably 3.5 or less, more preferably 4.0 or less, more preferably 4.5 or less, more preferably 4.7 or less, more preferably 5.0 or less, more preferably 5.3 or less, and still more preferably 5.5 or less.

[0096] By setting the sulfuric acid resistance parameter S within this range, it is possible to suppress occurrence of cloudy defects (cloudy portions) at the time of exposure to acid.

[0097] The sulfuric acid resistance parameter S is calculated from Formula (4).

[00004]$\begin{array}{cc}S=\left[\mathrm{BaO}\right]=3.75{\log }_{10}\left(\mathrm{amount}\mathrm{of}\mathrm{weight}\mathrm{change}\mathrm{at}\mathrm{the}\mathrm{time}\mathrm{of}\mathrm{exposure}\mathrm{to}\mathrm{acid}\right)& \left(4\right)\end{array}$

[0098] Note that the BaO content and the amount of weight change at the time of exposure to acid shown in Formula (4) may be 0.

(Acid Resistance Parameter)

[0099] The acid resistance parameter T of the glass 10 calculated from the composition is preferably 1.0 or more, more preferably 0.5 or more, more preferably 0.0 or more, more preferably 0.15 or more, more preferably 0.3 or more, more preferably 0.5 or more, more preferably 0.65 or more, more preferably 0.8 or more, more preferably 0.9 or more, more preferably 1.0 or more, and still more preferably 1.05 or more. By setting the acid resistance parameter T within this range, it is possible to suppress a weight change at the time of exposure to acid (for example, sulfuric acid).

[0100] The acid resistance parameter T is calculated from Formula (5).

[00005]$\begin{array}{cc}A=0.1\left[{\mathrm{SiO}}_2\right]+0.017\left[{\mathrm{Al}}_2{O}_3\right]+0.025\left[B_2{O}_3\right]+0.044\left[\mathrm{MgO}\right]+0.003\left[\mathrm{CaO}\right]-0.001\left[\mathrm{SrO}\right]-0.001\left[\mathrm{BaO}\right]+0.036\left[{\mathrm{Li}}_{2}O\right]+0.002\left[\mathrm{ZnO}\right]+0.183\left[{\mathrm{ZrO}}_2\right]+0.114\left[{\mathrm{TiO}}_2\right]+0.012\left[Y_2{O}_3\right]-0.06\left[{\mathrm{Gd}}_2{O}_3\right]-0.001\left[{\mathrm{La}}_2{O}_3\right]+0.329\left[{\mathrm{Ta}}_2{O}_5\right]-5.97& \left(5\right)\end{array}$

[0101] Note that the content of the oxide R.sub.xO.sub.y (R is an element constituting the oxide, and x and y are any suitable integers) contained in the glass 10 in terms of mol % on an oxide basis is represented by [R.sub.xO.sub.y]. The content herein refers to the ratio of the content of the oxide R.sub.xO.sub.y to the entire glass 10 in terms of mol % on an oxide basis. That is, for example, [SiO.sub.2] in Formula (5) refers to the ratio of the content of SiO.sub.2 to the entire glass 10 in terms of mol % on an oxide basis.

[0102] The glass 10 need not contain all the oxides shown in Formula (5). In Formula (5), the content of the oxide not contained in the glass 10 is treated as zero. In addition, the glass 10 may contain a component other than the oxides shown in Formula (5).

Method for Manufacturing Glass

[0103] The glass 10 may be manufactured by any method, but is manufactured, for example, by the following method. First, raw materials such as silica sand and soda ash, which are raw materials of the compounds contained in the glass 10, are melted by heating at a predetermined temperature (for example, 1500 C. to 1600 C.). Then, after the melted raw materials (glass) are clarified, a molding step of molding the glass into a plate shape is performed. The molded glass has the composition range of the glass 10 described above on an oxide basis. Then, a slow cooling step is performed on the glass molded in the molding step to manufacture glass 10.

[0104] Note that the method for manufacturing the glass 10 is not limited to the above, and may be any method. For example, the slow cooling step is not essential. In addition, various methods can be adopted as the molding step in manufacturing the glass 10, and examples thereof include a melt casting method, down-draw methods (for example, an overflow down-draw method, a slot down method, a redraw method, and the like), a float method, a roll-out method, and a press method.

[0105] Next, an example of a manufacturing step performed when the glass 10 is used for FOWLP manufacturing will be described. In the FOWLP manufacturing, a plurality of semiconductor chips are bonded onto the glass 10, and the semiconductor chips are covered with an encapsulant to form an element substrate. Then, the glass 10 and the element substrate are separated, and the opposite side of the element substrate from the semiconductor chips is bonded onto, for example, another glass 10. Then, wiring, solder bumps, and the like are formed on the semiconductor chips, and the element substrate and the glass 10 are separated again. Then, the element substrate is cut into pieces for each semiconductor chip, thereby obtaining a semiconductor device.

Effects

[0106] As described above, a glass 10 according to a first aspect of the present disclosure contains, [0107] SiO.sub.2: 40% to 60%,

[0108] B.sub.203: 0.01% to 15%, and [0109] Al.sub.2O.sub.3+rare earth oxide: 0% to 20%, [0110] as expressed in mol % on an oxide basis [0111] a parameter A, which is a ratio of the total content of Al.sub.2O.sub.3 and RO to the total content of SiO.sub.2, Al.sub.2O.sub.3, and RO, being 0.38 or more.

[0112] According to the present disclosure, when the parameter A falls within the above range, the melting temperature of the glass 10 can be lowered, and thus manufacturing can be facilitated. When the contents of other components fall within the above ranges, deflection can be suppressed. Thus, according to the present disclosure, manufacturing can be facilitated while deflection is suppressed.

[0113] In addition, for example, a glass having a high Young's modulus and a low coefficient of thermal expansion for suppressing deflection has a high melting temperature and thus may be difficult to manufacture. On this matter, in the present disclosure, by adopting the above-described composition, an increase in the melting temperature can be suppressed, and thus manufacturing can be facilitated.

[0114] A glass 10 according to a second aspect of the present disclosure is the glass 10 according to the first aspect, and preferably contains [0115] SiO.sub.2: 41% to 59%, [0116] B.sub.2O.sub.3: 1% to 12%, [0117] Al.sub.2O.sub.3: 5% to 20%, and [0118] (Y.sub.2O.sub.3+Gd.sub.2O.sub.3+Ta.sub.2O.sub.5+La.sub.2O.sub.3+Nd.sub.2O.sub.3+Nb.sub.2O.sub.5): 0.5% or more, [0119] as expressed in mol % on an oxide basis. By adjusting the content of each component within this range, manufacturing can be facilitated while deflection is suppressed.

[0120] A glass 10 according to a third aspect of the present disclosure is the glass 10 according to the first aspect or the second aspect, preferably has a transmittance of light with a wavelength of 308 nm at a thickness of 0.7 mm of 30% or more. When the transmittance falls within this range, ultraviolet rays can be appropriately transmitted.

[0121] A glass 10 according to a fourth aspect of the present disclosure is the glass 10 according to any one of the first to third aspects, and preferably satisfies

[00006]$0.1\left\{\left({\mathrm{Al}}_2{O}_3+\mathrm{MgO}\right)/\left({\mathrm{SiO}}_2+{\mathrm{Al}}_2{O}_3+B_2{O}_3+\mathrm{MgO}\right)\right\}1.,$$0.3\left(\mathrm{MgO}/{}_{\mathrm{RO}}\right)1,\mathrm{and}$$0\%{\mathrm{Al}}_2{O}_3+\mathrm{rare}\mathrm{earth}\mathrm{oxide}20\%,$ [0122] as expressed in mol % on an oxide basis. As a result, since the Young's modulus can be increased, the coefficient of linear thermal expansion can be decreased, and the liquidus temperature can be decreased, manufacturing can be facilitated while deflection is suppressed.

[0123] A glass 10 according to a fifth aspect of the present disclosure is the glass 10 according to any one of the first to fourth aspects, and preferably has a Young's modulus parameter Y calculated by Formula (1) of 0.8 or more, a thermal expansion parameter C calculated by Formula (2) of 1.2 or less, and a liquidus parameter L calculated by Formula (3) of 10.5 or less. As a result, since the Young's modulus can be increased, the coefficient of linear thermal expansion can be decreased, and the liquidus temperature can be decreased, manufacturing can be facilitated while deflection is suppressed.

[0124] A glass 10 according to a sixth aspect of the present disclosure is the glass 10 according to any one of the first to fifth aspects, and is preferably used as a substrate. The glass 10 of the present disclosure is suitably used for a substrate.

[0125] A glass 10 according to a seventh aspect of the present disclosure is the glass 10 according to the sixth aspect, and is preferably used in manufacture of at least one of a fan out wafer level package or a fan out panel level package. The glass 10 is suitably used for these applications.

EXAMPLES

[0126] Next, examples will be described. Tables 1 to 117 are tables showing properties of the glass of each example. Note that the embodiment may be changed as long as the effects of the invention are obtained.

TABLE-US-00001 TABLE 1 (mol %) Example 1 Example 2 Example 3 Example 4 SiO.sub.2 48 49 50 49 Al.sub.2O.sub.3 12 12 12 13 B.sub.2O.sub.3 7 7 7 7 MgO 22 22 22 23 CaO 2 2 2 2 SrO 2 2 2 2 BaO 2 2 2 2 Li.sub.2O 1 Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 1 1 1 Gd.sub.2O.sub.3 1 1 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14 14 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 1 0 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.44 0.46 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.37 0.39 MgO/RO 0.79 0.79 0.79 0.79 N 12 11 10 9 Young's modulus E (GPa) 101 98 96 95 Coefficient of thermal expansion (ppm/ C.) 4.95 4.76 4.52 4.41 Liquidus temperature TL ( C.) 1155 1150 1185 1215 Young's modulus parameter Y 1.00 0.98 0.96 0.96 Liquidus parameter L 9.3 9.6 9.7 9.8 Thermal expansion parameter C 0.99 0.95 0.91 0.90 Glass transition point ( C.) 697 725 724 722 Density (g/cm.sup.3) 2.90 2.89 2.78 2.72 Liquidus viscosity log .sub.L (dPa .Math. s) 3.17 3.32 3.15 2.9 K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 85 85 85 85 Transmittance (%) @550 nm, 0.7 mmt 90 90 90 90 Transmittance (%) @1064 nm, 0.7 mmt 85 85 85 85 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Sulfuric acid resistance (amount of weight loss (mg/cm.sup.2)) 0.095 Sulfuric acid resistance (transmission ability) x Sulfuric acid resistance parameter S 1.83 Acid resistance parameter T 0.51 0.58 0.74 0.68 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 5 Example 6 Example 7 Example 8 SiO.sub.2 48 48 48 48 Al.sub.2O.sub.3 12 11 10 12 B.sub.2O.sub.3 7 7 7 7 MgO 22 22 22 20 CaO 2 3 3 3 SrO 3 3 3 3 BaO 2 3 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 1 1 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 1 Al.sub.2O.sub.3 + rare earth oxide 14 12 11 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 1 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.47 0.46 0.46 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.37 0.37 MgO/RO 0.76 0.71 0.71 0.69 N 10 10 11 10 Young's modulus E (GPa) 99 96 97 98 Coefficient of thermal expansion (ppm/ C.) 4.9 5.01 4.96 5 Liquidus temperature TL ( C.) 1155 1175 1165 1155 Young's modulus parameter Y 0.99 0.95 0.96 0.97 Liquidus parameter L 9.5 9.6 9.5 9.7 Thermal expansion parameter C 0.98 1.01 1.01 1.01 Glass transition point ( C.) 718 710 708 718 Density (g/cm.sup.3) 2.87 2.85 2.97 2.90 Liquidus viscosity log .sub.L (dPa .Math. s) 3.27 3.08 3.17 3.14 K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 85 85 85 85 Transmittance (%) @550 nm, 0.7 mmt 90 90 90 90 Transmittance (%) @1064 nm, 0.7 mmt 85 85 85 85 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Sulfuric acid resistance (amount of weight loss (mg/cm.sup.2)) 0.091 0.095 Sulfuric acid resistance (transmission ability) x x Sulfuric acid resistance parameter S 1.90 0.83 Acid resistance parameter T 0.55 0.52 0.83 0.46 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00002 TABLE 2 (mol %) Example 9 Example 10 Example 11 Example 12 SiO.sub.2 47 48 48 48 Al.sub.2O.sub.3 12 11 11 12 B.sub.2O.sub.3 9 7 7 7 MgO 22 22 22 22 CaO 2 3 3 3 SrO 2 3 3 3 BaO 2 3 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 TiO.sub.2 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14 13 13 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.47 0.47 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.38 0.38 MgO/RO 0.79 0.71 0.71 0.71 N 10 9 9 8 Young's modulus E (GPa) 98 98 96.6 96.6 Coefficient of thermal expansion (ppm/ C.) 4.68 5.14 5.22 5.08 Liquidus temperature TL ( C.) 1130 1155 1170 1175 Young's modulus parameter Y 0.97 0.97 0.96 0.96 Liquidus parameter L 9.4 9.3 9.4 9.4 Thermal expansion parameter C 0.96 1.03 1.02 1.01 Glass transition point ( C.) 717 709 710 709 Density (g/cm.sup.3) 2.82 2.91 2.89 2.88 Liquidus viscosity log .sub.L (dPa .Math. s) 3.23 3.08 2.5< 2.5< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 85 85 85 85 Transmittance (%) @550 nm, 0.7 mmt 90 90 90 90 Transmittance (%) @1064 nm, 0.7 mmt 85 85 85 85 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Sulfuric acid resistance (amount of weight loss (mg/cm.sup.2)) 0.181 0.171 0.281 Sulfuric acid resistance (transmission ability) x x x Sulfuric acid resistance parameter S 0.22 0.12 0.93 Acid resistance parameter T 0.50 0.42 0.35 0.25 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 13 Example 14 Example 15 Example 16 SiO.sub.2 51 52 50 48 Al.sub.2O.sub.3 12 11 10 11 B.sub.2O.sub.3 5 3 6 7 MgO 20 22 22 22 CaO 3 3 2 2 SrO 3 3 2 2 BaO 3 2 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 15 13 12 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 3 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.44 0.44 0.46 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.38 0.36 0.38 MgO/RO 0.69 0.73 0.73 0.73 N 8 10 10 10 Young's modulus E (GPa) 98.9 100.5 97 96.4 Coefficient of thermal expansion (ppm/ C.) 5.04 4.97 5.06 5.21 Liquidus temperature TL ( C.) 1185 1210 1190 1150 Young's modulus parameter Y 0.98 1.01 0.96 0.96 Liquidus parameter L 9.7 10.0 9.8 9.8 Thermal expansion parameter C 1.00 0.99 1.00 1.00 Glass transition point ( C.) 724 731 722 722 Density (g/cm.sup.3) 2.94 2.91 2.91 2.92 Liquidus viscosity log .sub.L (dPa .Math. s) 2.5< 2.94 2.84 3.09 K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 85 85 85 85 Transmittance (%) @550 nm, 0.7 mmt 90 90 90 90 Transmittance (%) @1064 nm, 0.7 mmt 85 85 85 85 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Sulfuric acid resistance (amount of weight loss (mg/cm.sup.2)) 0.224 0.047 0.096 Sulfuric acid resistance (transmission ability) x x x Sulfuric acid resistance parameter S 0.56 0.98 0.18 Acid resistance parameter T 0.43 0.83 0.69 0.53 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00003 TABLE 3 (mol %) Example 17 Example 18 Example 19 Example 20 SiO.sub.2 49 52 52 52 Al.sub.2O.sub.3 11 11 11 11 B.sub.2O.sub.3 7 5 5 5 MgO 19 18 19 18 CaO 3 2 2 3 SrO 3 3 3 3 BaO 3 4 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 3 3 3 3 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14 14 14 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 3 3 3 3 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.42 0.42 0.42 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.34 0.34 0.34 MgO/RO 0.68 0.67 0.70 0.67 N 10 10 10 10 Young's modulus E (GPa) 98 97 98 97 Coefficient of thermal expansion (ppm/ C.) 5.4 5.16 4.87 4.96 Liquidus temperature TL ( C.) 1110 1230 1155 1165 Young's modulus parameter Y 0.97 0.97 0.98 0.98 Liquidus parameter L 9.6 10.1 10.0 10.0 Thermal expansion parameter C 1.03 1.00 0.99 1.00 Glass transition point ( C.) 720 732 732 731 Density (g/cm.sup.3) 2.98 2.99 2.94 2.93 Liquidus viscosity log .sub.L (dPa .Math. s) 2.5< 2.3< 2.5< 2.5< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 85 85 85 85 Transmittance (%) @550 nm, 0.7 mmt 90 90 90 90 Transmittance (%) @1064 nm, 0.7 mmt 85 85 85 85 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Sulfuric acid resistance (amount of weight loss (mg/cm.sup.2)) 0.082 0.056 Sulfuric acid resistance (transmission ability) x x Sulfuric acid resistance parameter S 1.07 0.69 Acid resistance parameter T 0.51 0.71 0.76 0.72 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 21 Example 22 Example 23 Example 24 SiO.sub.2 50 50 48 48 Al.sub.2O.sub.3 11 11 11 11 B.sub.2O.sub.3 5 5 5 5 MgO 17 15 17 17 CaO 3 4 4 4 SrO 4 4 4 4 BaO 4 5 5 5 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 4 4 4 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 15 15 15 15 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 4 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.46 0.46 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.32 0.35 0.35 MgO/RO 0.61 0.54 0.57 0.57 N 10 10 10 11 Young's modulus E (GPa) 98 98 100 98 Coefficient of thermal expansion (ppm/ C.) 5.11 5.48 5.79 5.73 Liquidus temperature TL ( C.) 1235 1275 1295 1295 Young's modulus parameter Y 0.99 0.97 0.99 0.98 Liquidus parameter L 10.0 10.2 10.0 9.8 Thermal expansion parameter C 1.08 1.11 1.14 1.16 Glass transition point ( C.) 725 725 721 720 Density (g/cm.sup.3) 3.06 3.11 3.13 3.19 Liquidus viscosity log .sub.L (dPa .Math. s) 2.3< 1.8< 1.7< 1.7< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Transmittance (%) @1064 nm, 0.7 mmt 85 85 85 85 T.sub.2 ( C.) <1300 <1300 <1300 <1300 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Sulfuric acid resistance (amount of weight loss (mg/cm.sup.2)) Sulfuric acid resistance (transmission ability) Sulfuric acid resistance parameter S Acid resistance parameter T 0.48 0.40 0.28 0.26 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00004 TABLE 4 (mol %) Example 25 Example 26 Example 27 Example 28 SiO.sub.2 50 50 50.6 47.9 Al.sub.2O.sub.3 7 11 8 8 B.sub.2O.sub.3 3 5 3 3 MgO 16 12 16.4 19.1 CaO 5 4 4 5 SrO 4 4 4 4 BaO 4 5 3 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 8 5 5 P.sub.2O.sub.5 ZrO.sub.2 1.2 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 0.8 7 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 4 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 7.8 18 12.0 10.0 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 0.8 7 4 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.42 0.44 0.48 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.30 0.29 0.31 0.35 MgO/RO 0.43 0.48 0.51 0.51 N 11 10 11 11 Young's modulus E (GPa) 96 100 99 99 Coefficient of thermal expansion (ppm/ C.) 5.50 5.69 5.81 5.78 Liquidus temperature TL ( C.) 1185 1295 1185 1225 Young's modulus parameter Y 0.95 1.01 1.00 0.99 Liquidus parameter L 9.5 10.2 9.1 9.5 Thermal expansion parameter C 1.11 1.16 1.16 1.16 Glass transition point ( C.) 675 736 698 688 Density (g/cm.sup.3) 3.12 3.25 3.32 3.22 Liquidus viscosity log .sub.L (dPa .Math. s) 2.5< 1.7< 2.64 2.2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.89 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 34.5 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 84.2 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 89.3 88 Transmittance (%) @1064 nm, 0.7 mmt 85 85 89.5 85 T.sub.2 ( C.) <1300 <1300 <1300 <1300 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Sulfuric acid resistance (amount of weight loss (mg/cm.sup.2)) 0.165 Sulfuric acid resistance (transmission ability) x Sulfuric acid resistance parameter S 0.07 Acid resistance parameter T 0.34 0.30 0.38 0.26 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 29 Example 30 Example 31 Example 32 SiO.sub.2 48.2 49.1 49.3 48 Al.sub.2O.sub.3 8 8 8 11 B.sub.2O.sub.3 3 3 3.1 5 MgO 19.8 23.9 24.7 17 CaO 4 4 3 2 SrO 4 4 3 6 BaO 4 4 3 2 Li.sub.2O 3 Na.sub.2O K.sub.2O ZnO 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 4 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 2 4 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 10.0 10.0 12.0 15 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.47 0.46 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.38 0.38 0.35 MgO/RO 0.54 0.67 0.73 0.63 N 11 10 10 11 Young's modulus E (GPa) 99 99 102 104 Coefficient of thermal expansion (ppm/ C.) 5.85 5.93 6.00 5.82 Liquidus temperature TL ( C.) 1225 1290 1290 1225 Young's modulus parameter Y 0.98 0.99 1.03 1.06 Liquidus parameter L 9.3 9.3 9.0 8.8 Thermal expansion parameter C 1.16 1.16 1.16 1.17 Glass transition point ( C.) 688 707 720 644 Density (g/cm.sup.3) 3.22 3.13 3.25 3.06 Liquidus viscosity log .sub.L (dPa .Math. s) 2.2< 1.7< 1.7< 2.28 K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.94 Transmittance (%) @308 nm, 0.7 mmt 30 30 30 39.4 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 87.9 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 89.8 Transmittance (%) @1064 nm, 0.7 mmt 85 85 85 90.1 T.sub.2 ( C.) <1300 1279 <1300 <1300 T.sub.3 ( C.) <1200 1152 <1200 <1200 T.sub.4 ( C.) <1100 1063 <1100 <1100 Sulfuric acid resistance (amount of weight loss (mg/cm.sup.2)) 0.169 Sulfuric acid resistance (transmission ability) x Sulfuric acid resistance parameter S 0.90 Acid resistance parameter T 0.29 0.55 0.60 0.39 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00005 TABLE 5 (mol %) Example 33 Example 34 Example 35 Example 36 Example 37 SiO.sub.2 48 51 51 52.5 51.4 Al.sub.2O.sub.3 12 13 12 12.5 12.3 B.sub.2O.sub.3 7 7 7 7.5 8 MgO 20 21 21 21.5 21 CaO 3 1 2 1 1.3 SrO 2 1 1 1 1.3 BaO 2 1 1 0.5 0.3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 Y.sub.2O.sub.3 2 3 3 1.5 2.4 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 16 16 15 14 14.7 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 3 3 1.5 2.4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.42 0.42 0.41 0.41 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.36 0.36 0.36 MgO/RO 0.74 0.88 0.84 0.90 0.88 N 11 10 10 10 9 Young's modulus E (GPa) 100 100 100 101 99 Coefficient of thermal expansion (ppm/ C.) 5.25 4.36 4.47 4.30 4.22 Liquidus temperature TL ( C.) 1120 1195 1175 1235 1175 Young's modulus parameter Y 1.01 1.00 1.00 0.97 0.99 Liquidus parameter L 9.4 9.9 9.7 9.8 9.6 Thermal expansion parameter C 1.02 0.87 0.90 0.82 0.86 Glass transition point ( C.) 729 744 739 737 734 Density (g/cm.sup.3) 3.03 2.82 2.82 2.84 2.76 Liquidus viscosity log .sub.L (dPa .Math. s) 3.6 3.15 2.5< 2.5< 2.5< K.sub.IC (MPa .Math. m.sup.0.5) 0.93 0.95 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 34.2 33.8 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 88.8 85.3 80 80 80 Transmittance (%) @550 nm, 0.7 mmt 90.0 90.3 88 88 88 Transmittance (%) @1064 nm, 0.7 mmt 90.2 90.6 90 90 90 T.sub.2 ( C.) 1296 1359 <1400 <1400 <1400 T.sub.3 ( C.) 1168 1213 <1250 <1250 <1250 T.sub.4 ( C.) 1079 1113 <1150 <1150 <1150 Sulfuric acid resistance (amount of weight loss (mg/cm.sup.2)) 0.098 0.019 Sulfuric acid resistance (transmission ability) x x Sulfuric acid resistance parameter S 1.78 5.45 Acid resistance parameter T 0.46 0.83 0.82 0.99 0.88 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 38 Example 39 Example 40 SiO.sub.2 51.2 49 50.8 Al.sub.2O.sub.3 12.1 14 12.9 B.sub.2O.sub.3 8 8 7 MgO 21.4 21.4 22.4 CaO 1.3 1.3 1 SrO 1.3 1.3 1 BaO 0.6 0.6 1 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14.1 16.0 14.9 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2.0 2.0 2.0 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.42 0.44 0.43 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.38 0.38 MgO/RO 0.87 0.87 0.88 N 10 10 10 Young's modulus E (GPa) 97 100 98 Coefficient of thermal expansion (ppm/ C.) 4.21 4.25 4.27 Liquidus temperature TL ( C.) 1185 1205 1205 Young's modulus parameter Y 0.98 1.00 0.99 Liquidus parameter L 9.6 9.7 9.8 Thermal expansion parameter C 0.86 0.86 0.86 Glass transition point ( C.) 732 733 739 Density (g/cm.sup.3) 2.74 2.76 2.75 Liquidus viscosity log .sub.L (dPa .Math. s) 2.5< 2.99 2.5< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 80 80 80 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Transmittance (%) @1064 nm, 0.7 mmt 90 90 90 T.sub.2 ( C.) <1400 1351 <1400 T.sub.3 ( C.) <1250 1204 <1250 T.sub.4 ( C.) <1150 1104 <1150 Sulfuric acid resistance (amount of weight loss (mg/cm.sup.2)) Sulfuric acid resistance (transmission ability) Sulfuric acid resistance parameter S Acid resistance parameter T 0.87 0.68 0.85 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00006 TABLE 6 (mol %) Example 41 Example 42 Example 43 Example 44 SiO.sub.2 50 50 50 50 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 6 6 6 6 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 Gd.sub.2O.sub.3 0.5 1 1.5 La.sub.2O.sub.3 2 1.5 1 0.5 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 0.36 MgO/RO 0.73 0.73 0.73 0.73 N 10 11 11 11 Young's modulus E (GPa) 97 97 97 97 Coefficient of thermal expansion (ppm/ C.) 5.23 5.25 5.26 5.28 Liquidus temperature TL ( C.) 1218 1217 1212 1212 Young's modulus parameter Y 0.95 0.95 0.95 0.95 Liquidus parameter L 9.6 9.6 9.6 9.6 Thermal expansion parameter C 1.02 1.02 1.02 1.02 Glass transition point ( C.) 705 704 703 703 Density (g/cm.sup.3) 2.99 2.99 3.00 3.00 Liquidus viscosity log .sub.L (dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.66 0.83 0.60 0.57 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 45 Example 46 Example 47 SiO.sub.2 50 50 50 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 6 6 6 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 0.5 0.5 Gd.sub.2O.sub.3 2 0.5 La.sub.2O.sub.3 1.5 1 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 MgO/RO 0.73 0.73 0.73 N 10 11 12 Young's modulus E (GPa) 97 97 97 Coefficient of thermal expansion (ppm/ C.) 5.30 5.19 5.21 Liquidus temperature TL ( C.) 1209 1205 1203 Young's modulus parameter Y 0.95 0.96 0.96 Liquidus parameter L 9.6 9.6 9.6 Thermal expansion parameter C 1.02 1.01 1.01 Glass transition point ( C.) 704 705 704 Density (g/cm.sup.3) 3.01 2.97 2.97 Liquidus viscosity log .sub.L (dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.54 0.67 0.64 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00007 TABLE 7 (mol %) Example 48 Example 49 Example 50 Example 51 SiO.sub.2 50 50 50 50 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 6 6 6 6 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 0.5 0.5 1 1 Gd.sub.2O.sub.3 1 1.5 0.5 La.sub.2O.sub.3 0.5 1 0.5 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 0.36 MgO/RO 0.73 0.73 0.73 0.73 N 12 11 11 12 Young's modulus E (GPa) 97 97 97 97 Coefficient of thermal expansion (ppm/ C.) 5.23 5.24 5.15 5.17 Liquidus temperature TL ( C.) 1201 1198 1194 1192 Young's modulus parameter Y 0.96 0.96 0.96 0.96 Liquidus parameter L 9.6 9.6 9.7 9.7 Thermal expansion parameter C 1.01 1.01 1.01 1.01 Glass transition point ( C.) 703 703 705 704 Density (g/cm.sup.3) 2.98 2.98 2.95 2.95 Liquidus viscosity log .sub.L (dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.84 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.61 0.58 0.67 0.64 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 52 Example 53 Example 54 SiO.sub.2 50 50 50 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 6 6 6 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 1 1.5 1.5 Gd.sub.2O.sub.3 1 0.5 La.sub.2O.sub.3 0.5 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 MgO/RO 0.73 0.73 0.73 N 11 11 11 Young's modulus E (GPa) 97 97 97 Coefficient of thermal expansion (ppm/ C.) 5.19 5.11 5.13 Liquidus temperature TL ( C.) 1187 1192 1190 Young's modulus parameter Y 0.96 0.96 0.96 Liquidus parameter L 9.7 9.8 9.8 Thermal expansion parameter C 1.01 1.00 1.00 Glass transition point ( C.) 703 705 704 Density (g/cm.sup.3) 2.96 2.93 2.94 Liquidus viscosity log .sub.L (dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.61 0.68 0.65 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00008 TABLE 8 (mol %) Example 55 Example 56 Example 57 Example 58 SiO.sub.2 48 48 48.0 48 Al.sub.2O.sub.3 9 9 9 9 B.sub.2O.sub.3 5 7 7 7 MgO 22 22 22.0 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1.0 1.0 1 TiO.sub.2 1 1.0 1.0 1 Y.sub.2O.sub.3 2 2.0 2 Gd.sub.2O.sub.3 2 2 2 La.sub.2O.sub.3 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 15 13 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 6 4 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.45 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.36 0.36 0.36 MgO/RO 0.73 0.73 0.73 0.73 N 12 11 11 11 Young's modulus E (GPa) 103 99 99 99 Coefficient of thermal expansion (ppm/ C.) 5.93 5.72 5.50 5.57 Liquidus temperature TL ( C.) 1199 1188 1149 1157 Young's modulus parameter Y 1.03 0.98 0.98 0.98 Liquidus parameter L 9.2 9.0 9.2 9.2 Thermal expansion parameter C 1.16 1.10 1.09 1.09 Glass transition point ( C.) 706 697 699 697 Density (g/cm.sup.3) 3.33 3.20 3.10 3.12 Liquidus viscosity log .sub.L (dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.32 0.35 0.49 0.37 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 59 Example 60 Example 61 SiO.sub.2 48 48 48 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 4 6 6 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 16 14 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 6 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.37 0.37 MgO/RO 0.73 0.73 0.73 N 12 11 11 Young's modulus E (GPa) 104 100 100 Coefficient of thermal expansion (ppm/ C.) 5.89 5.69 5.46 Liquidus temperature TL ( C.) 1225 1210 1170 Young's modulus parameter Y 1.05 0.99 1.00 Liquidus parameter L 9.4 9.2 9.5 Thermal expansion parameter C 1.15 1.10 1.08 Glass transition point ( C.) 716 704 705 Density (g/cm.sup.3) 3.34 3.21 3.11 Liquidus viscosity log .sub.L (dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.32 0.34 0.48 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00009 TABLE 9 (mol %) Example 62 Example 63 Example 64 Example 65 SiO.sub.2 48 48 48 48 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 6 8 8 8 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.45 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.36 0.36 0.36 MgO/RO 0.73 0.73 0.73 0.73 N 11 10 10 10 Young's modulus E (GPa) 100 97 97 97 Coefficient of thermal expansion (ppm/ C.) 5.54 5.26 5.33 5.11 Liquidus temperature TL ( C.) 1174 1190 1186 1148 Young's modulus parameter Y 1.00 0.94 0.94 0.95 Liquidus parameter L 9.5 9.3 9.3 9.5 Thermal expansion parameter C 1.08 1.03 1.03 1.01 Glass transition point ( C.) 704 699 697 699 Density (g/cm.sup.3) 3.13 2.99 3.00 2.91 Liquidus viscosity log .sub.L (dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.37 0.51 0.39 0.54 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1300 <1300 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 66 Example 67 Example 68 SiO.sub.2 48 48 48 Al.sub.2O.sub.3 11 11 11 B.sub.2O.sub.3 5 5 5 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 15 15 15 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.46 0.46 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.38 MgO/RO 0.73 0.73 0.73 N 11 11 11 Young's modulus E (GPa) 101 101 101 Coefficient of thermal expansion (ppm/ C.) 5.66 5.43 5.50 Liquidus temperature TL ( C.) 1233 1193 1196 Young's modulus parameter Y 1.01 1.01 1.01 Liquidus parameter L 9.5 9.7 9.7 Thermal expansion parameter C 1.09 1.07 1.07 Glass transition point ( C.) 707 709 707 Density (g/cm.sup.3) 3.22 3.13 3.14 Liquidus viscosity log .sub.L (dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.33 0.48 0.36 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1300 <1300 <1300 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00010 TABLE 10 (mol %) Example 69 Example 70 Example 71 Example 72 SiO.sub.2 48 48 48 48 Al.sub.2O.sub.3 11 11 12 12 B.sub.2O.sub.3 7 7 4 4 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 16 16 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.46 0.47 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.40 0.40 MgO/RO 0.73 0.73 0.73 0.73 N 10 10 11 11 Young's modulus E (GPa) 98 98 103 103 Coefficient of thermal expansion (ppm/ C.) 5.23 5.30 5.63 5.40 Liquidus temperature TL ( C.) 1190 1186 1262 1231 Young's modulus parameter Y 0.96 0.96 1.02 1.03 Liquidus parameter L 9.5 9.5 9.7 9.9 Thermal expansion parameter C 1.02 1.02 1.08 1.07 Glass transition point ( C.) 700 698 716 718 Density (g/cm.sup.3) 3.00 3.01 3.23 3.14 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.50 0.38 0.33 0.47 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1300 <1400 <1400 <1400 T.sub.3 ( C.) <1200 <1300 <1300 <1300 T.sub.4 ( C.) <1100 <1200 <1200 <1200 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 73 Example 74 Example 75 SiO.sub.2 48 48 48 Al.sub.2O.sub.3 12 12 12 B.sub.2O.sub.3 4 6 6 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 16 14 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.47 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.40 0.39 0.39 MgO/RO 0.73 0.73 0.73 N 11 10 10 Young's modulus E (GPa) 103 99 99 Coefficient of thermal expansion (ppm/ C.) 5.47 5.20 5.27 Liquidus temperature TL ( C.) 1233 1212 1205 Young's modulus parameter Y 1.03 0.97 0.97 Liquidus parameter L 9.9 9.8 9.8 Thermal expansion parameter C 1.07 1.01 1.01 Glass transition point ( C.) 716 705 704 Density (g/cm.sup.3) 3.15 3.01 3.02 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.35 0.50 0.38 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1300 <1400 <1400 T.sub.3 ( C.) <1200 <1300 <1300 T.sub.4 ( C.) <1100 <1200 <1200 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00011 TABLE 11 (mol %) Example 78 Example 77 Example 78 Example 79 SiO.sub.2 48 48 48.0 48.0 Al.sub.2O.sub.3 12 12 13.0 13.0 B.sub.2O.sub.3 6 8 5.0 5.0 MgO 22 22 22.0 22.0 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14 12 15 15 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 0 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.47 0.47 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.39 0.38 0.40 0.40 MgO/RO 0.73 0.73 0.73 0.73 N 10 9 10 10 Young's modulus E (GPa) 99 95 100 100 Coefficient of thermal expansion (ppm/ C.) 5.04 4.84 5.16 5.24 Liquidus temperature TL ( C.) 1168 1185 1239 1233 Young's modulus parameter Y 0.98 0.92 0.99 0.99 Liquidus parameter L 10.0 9.8 10.0 10.0 Thermal expansion parameter C 1.00 0.94 1.01 1.01 Glass transition point ( C.) 705 700 713 711 Density (g/cm.sup.3) 2.93 2.80 3.02 3.03 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.52 0.55 0.49 0.37 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1400 <1300 <1300 <1300 T.sub.3 ( C.) <1300 <1200 <1200 <1200 T.sub.4 ( C.) <1200 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 80 Example 81 Example 82 SiO.sub.2 48.0 48.0 48.0 Al.sub.2O.sub.3 13.0 13.0 9.0 B.sub.2O.sub.3 5.0 7.0 4.0 MgO 22.0 22.0 22.0 CaO 2 2 2 SrO 2 2 2 BaO 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 15 13 15 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 0 6 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.47 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.40 0.39 0.37 MgO/RO 0.73 0.73 0.73 N 10 9 12 Young's modulus E (GPa) 100 97 103 Coefficient of thermal expansion (ppm/ C.) 5.01 4.81 5.91 Liquidus temperature TL ( C.) 1198 1208 1225 Young's modulus parameter Y 0.99 0.94 1.04 Liquidus parameter L 10.2 10.1 9.3 Thermal expansion parameter C 0.99 0.94 1.15 Glass transition point ( C.) 713 705 716 Density (g/cm.sup.3) 2.94 2.81 3.33 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.51 0.54 0.40 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1300 <1300 <1300 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00012 TABLE 12 (mol %) Example 83 Example 84 Example 85 Example 86 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 9 9 9 9 B.sub.2O.sub.3 6 6 6 8 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 13 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 4 4 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 0.35 MgO/RO 0.73 0.73 0.73 0.73 N 11 11 11 10 Young's modulus E (GPa) 99 99 99 96 Coefficient of thermal expansion (ppm/ C.) 5.71 5.48 5.55 5.28 Liquidus temperature TL ( C.) 1211 1174 1173 1194 Young's modulus parameter Y 0.98 0.99 0.99 0.93 Liquidus parameter L 9.2 9.4 9.4 9.2 Thermal expansion parameter C 1.10 1.08 1.08 1.03 Glass transition point ( C.) 703 704 703 698 Density (g/cm.sup.3) 3.20 3.11 3.12 2.98 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.42 0.57 0.45 0.59 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1300 <1300 <1350 <1300 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 87 Example 88 Example 89 SiO.sub.2 49 49 49 Al.sub.2O.sub.3 9 9 10 B.sub.2O.sub.3 8 8 5 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 11 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.35 0.37 MgO/RO 0.73 0.73 0.73 N 10 10 11 Young's modulus E (GPa) 96 96 100 Coefficient of thermal expansion (ppm/ C.) 5.35 5.12 5.68 Liquidus temperature TL ( C.) 1185 1155 1232 Young's modulus parameter Y 0.93 0.94 1.00 Liquidus parameter L 9.2 9.4 9.4 Thermal expansion parameter C 1.03 1.01 1.09 Glass transition point ( C.) 696 698 707 Density (g/cm.sup.3) 2.99 2.90 3.21 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.47 0.62 0.42 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00013 TABLE 13 (mol %) Example 90 Example 91 Example 92 Example 93 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 5 5 7 7 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14 14 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 4 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.45 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.36 0.36 MgO/RO 0.73 0.73 0.73 0.73 N 11 11 10 10 Young's modulus E (GPa) 101 101 97 97 Coefficient of thermal expansion (ppm/ C.) 5.45 5.52 5.25 5.32 Liquidus temperature TL ( C.) 1195 1196 1195 1187 Young's modulus parameter Y 1.00 1.00 0.95 0.95 Liquidus parameter L 9.6 9.6 9.4 9.4 Thermal expansion parameter C 1.08 1.08 1.02 1.02 Glass transition point ( C.) 709 707 700 698 Density (g/cm.sup.3) 3.12 3.13 2.99 3.00 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.56 0.44 0.59 0.47 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 94 Example 95 Example 96 SiO.sub.2 49 49 49 Al.sub.2O.sub.3 10 11 11 B.sub.2O.sub.3 7 4 4 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 15 15 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.46 0.46 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.38 0.38 MgO/RO 0.73 0.73 0.73 N 10 11 11 Young's modulus E (GPa) 97 102 102 Coefficient of thermal expansion (ppm/ C.) 5.09 5.64 5.42 Liquidus temperature TL ( C.) 1159 1258 1223 Young's modulus parameter Y 0.95 1.01 1.02 Liquidus parameter L 9.7 9.6 9.8 Thermal expansion parameter C 1.01 1.09 1.07 Glass transition point ( C.) 700 716 719 Density (g/cm.sup.3) 2.91 3.22 3.13 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.61 0.41 0.55 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00014 TABLE 14 (mol %) Example 97 Example 98 Example 99 Example 100 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 11 11 11 11 B.sub.2O.sub.3 4 6 6 6 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 15 13 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.46 0.46 0.48 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.38 0.38 MgO/RO 0.73 0.73 0.73 0.73 N 11 10 10 10 Young's modulus E (GPa) 102 98 98 98 Coefficient of thermal expansion (ppm/ C.) 5.49 5.21 5.28 5.08 Liquidus temperature TL ( C.) 1223 1213 1205 1171 Young's modulus parameter Y 1.02 0.96 0.96 0.97 Liquidus parameter L 9.8 9.7 9.7 9.9 Thermal expansion parameter C 1.07 1.02 1.02 1.00 Glass transition point ( C.) 716 705 704 705 Density (g/cm.sup.3) 3.14 3.00 3.01 2.92 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.43 0.58 0.46 0.60 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 101 Example 102 Example 103 SiO.sub.2 49 49 49 Al.sub.2O.sub.3 11 12 12 B.sub.2O.sub.3 8 5 5 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 14 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 0 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.46 0.46 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.39 0.39 MgO/RO 0.73 0.73 0.73 N 9 10 10 Young's modulus E (GPa) 94 99 99 Coefficient of thermal expansion (ppm/ C.) 4.85 5.18 5.25 Liquidus temperature TL ( C.) 1189 1237 1227 Young's modulus parameter Y 0.91 0.98 0.98 Liquidus parameter L 9.7 9.9 9.9 Thermal expansion parameter C 0.95 1.01 1.01 Glass transition point ( C.) 699 709 707 Density (g/cm.sup.3) 2.79 3.01 3.03 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.63 0.57 0.45 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00015 TABLE 15 (mol %) Example 104 Example 105 Example 106 Example 107 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 12 12 13 13 B.sub.2O.sub.3 5 7 4 4 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14 12 15 15 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 0 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.46 0.47 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.39 0.38 0.40 0.40 MgO/RO 0.73 0.73 0.73 0.73 N 10 9 10 10 Young's modulus E (GPa) 99 96 100 100 Coefficient of thermal expansion (ppm/ C.) 5.02 4.82 5.15 5.22 Liquidus temperature TL ( C.) 1196 1190 1265 1257 Young's modulus parameter Y 0.98 0.93 0.99 0.99 Liquidus parameter L 10.1 10.0 10.1 10.1 Thermal expansion parameter C 0.99 0.94 1.00 1.00 Glass transition point ( C.) 709 701 722 720 Density (g/cm.sup.3) 2.93 2.80 3.02 3.04 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.60 0.62 0.56 0.45 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 108 Example 109 Example 110 SiO.sub.2 49 49 50 Al.sub.2O.sub.3 13 13 9 B.sub.2O.sub.3 4 6 5 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 15 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 0 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.47 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.40 0.39 0.36 MgO/RO 0.73 0.73 0.73 N 10 9 11 Young's modulus E (GPa) 100 97 100 Coefficient of thermal expansion (ppm/ C.) 4.99 4.79 5.69 Liquidus temperature TL ( C.) 1230 1218 1232 Young's modulus parameter Y 1.00 0.94 0.99 Liquidus parameter L 10.4 10.2 9.3 Thermal expansion parameter C 0.99 0.93 1.09 Glass transition point ( C.) 722 709 706 Density (g/cm.sup.3) 2.94 2.81 3.20 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.59 0.61 0.50 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00016 TABLE 16 (mol %) Example 111 Example 112 Example 113 Example 114 SiO.sub.2 50 50 50 50 Al.sub.2O.sub.3 9 9 9 9 B.sub.2O.sub.3 5 5 7 7 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 11 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 4 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.35 0.35 MgO/RO 0.73 0.73 0.73 0.73 N 11 11 10 10 Young's modulus E (GPa) 100 100 96 96 Coefficient of thermal expansion (ppm/ C.) 5.46 5.54 5.26 5.33 Liquidus temperature TL ( C.) 1205 1207 1204 1198 Young's modulus parameter Y 1.00 0.99 0.94 0.94 Liquidus parameter L 9.5 9.5 9.4 9.4 Thermal expansion parameter C 1.08 1.08 1.02 1.02 Glass transition point ( C.) 708 706 699 697 Density (g/cm.sup.3) 3.11 3.12 2.98 3.00 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.64 0.53 0.67 0.55 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 115 Example 116 Example 117 SiO.sub.2 50 50 50 Al.sub.2O.sub.3 9 10 10 B.sub.2O.sub.3 7 4 4 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 14 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.37 0.37 MgO/RO 0.73 0.73 0.73 N 10 11 11 Young's modulus E (GPa) 96 101 101 Coefficient of thermal expansion (ppm/ C.) 5.11 5.66 5.43 Liquidus temperature TL ( C.) 1185 1257 1227 Young's modulus parameter Y 0.94 1.00 1.01 Liquidus parameter L 9.6 9.5 9.7 Thermal expansion parameter C 1.01 1.09 1.07 Glass transition point ( C.) 699 716 718 Density (g/cm.sup.3) 2.90 3.21 3.12 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.69 0.49 0.64 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00017 TABLE 17 (mol %) Example 118 Example 119 Example 120 Example 121 SiO.sub.2 50 50 50 50 Al.sub.2O.sub.3 10 10 10 11 B.sub.2O.sub.3 4 6 6 5 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14 12 12 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.36 0.36 0.38 MgO/RO 0.73 0.73 0.73 0.73 N 11 10 10 10 Young's modulus E (GPa) 101 97 97 98 Coefficient of thermal expansion (ppm/ C.) 5.50 5.23 5.30 5.20 Liquidus temperature TL ( C.) 1229 1218 1209 1233 Young's modulus parameter Y 1.01 0.95 0.95 0.97 Liquidus parameter L 9.7 9.6 9.6 9.8 Thermal expansion parameter C 1.07 1.02 1.02 1.01 Glass transition point ( C.) 716 705 704 709 Density (g/cm.sup.3) 3.13 2.99 3.01 3.00 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.52 0.66 0.54 0.65 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 122 Example 123 Example 124 SiO.sub.2 50 50 50 Al.sub.2O.sub.3 11 11 11 B.sub.2O.sub.3 5 5 7 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 0 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.37 MgO/RO 0.73 0.73 0.73 N 10 10 9 Young's modulus E (GPa) 98 98 95 Coefficient of thermal expansion (ppm/ C.) 5.27 5.04 4.84 Liquidus temperature TL ( C.) 1224 1201 1201 Young's modulus parameter Y 0.97 0.97 0.92 Liquidus parameter L 9.8 10.0 9.9 Thermal expansion parameter C 1.01 0.99 0.94 Glass transition point ( C.) 707 709 700 Density (g/cm.sup.3) 3.02 2.92 2.79 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.54 0.68 0.70 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00018 TABLE 18 (mol %) Example 125 Example 126 Example 127 Example 128 SiO.sub.2 50 50 50 50 Al.sub.2O.sub.3 12 12 12 12 B.sub.2O.sub.3 4 4 4 6 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14 14 14 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 0 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.46 0.46 0.46 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.39 0.39 0.39 0.38 MgO/RO 0.73 0.73 0.73 0.73 N 10 10 10 9 Young's modulus E (GPa) 99 99 100 96 Coefficient of thermal expansion (ppm/ C.) 5.16 5.24 5.01 4.81 Liquidus temperature TL ( C.) 1265 1254 1236 1211 Young's modulus parameter Y 0.98 0.98 0.99 0.93 Liquidus parameter L 10.1 10.1 10.3 10.1 Thermal expansion parameter C 1.00 1.00 0.99 0.93 Glass transition point ( C.) 718 715 718 705 Density (g/cm.sup.3) 3.01 3.03 2.93 2.80 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.65 0.53 0.67 0.70 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 129 Example 130 Example 131 SiO.sub.2 50 51 51 Al.sub.2O.sub.3 13 9 9 B.sub.2O.sub.3 5 4 4 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 0 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.43 0.43 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.39 0.36 0.36 MgO/RO 0.73 0.73 0.73 N 9 11 11 Young's modulus E (GPa) 97 100 100 Coefficient of thermal expansion (ppm/ C.) 4.77 5.67 5.45 Liquidus temperature TL ( C.) 1233 1253 1222 Young's modulus parameter Y 0.95 1.00 1.00 Liquidus parameter L 10.4 9.4 9.7 Thermal expansion parameter C 0.93 1.09 1.07 Glass transition point ( C.) 713 715 718 Density (g/cm.sup.3) 2.82 3.20 3.11 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.69 0.58 0.72 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00019 TABLE 19 (mol %) Example 132 Example 133 Example 134 Example 135 SiO.sub.2 51 51 51 51 Al.sub.2O.sub.3 9 9 9 9 B.sub.2O.sub.3 4 6 6 6 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 11 11 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.43 0.43 0.43 0.43 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.35 0.35 0.35 MgO/RO 0.73 0.73 0.73 0.73 N 11 10 10 10 Young's modulus E (GPa) 100 96 96 96 Coefficient of thermal expansion (ppm/ C.) 5.52 5.24 5.32 5.09 Liquidus temperature TL ( C.) 1223 1217 1208 1189 Young's modulus parameter Y 1.00 0.95 0.95 0.95 Liquidus parameter L 9.7 9.5 9.5 9.7 Thermal expansion parameter C 1.07 1.02 1.02 1.00 Glass transition point ( C.) 715 704 703 704 Density (g/cm.sup.3) 3.13 2.98 3.00 2.90 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.60 0.74 0.63 0.77 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 136 Example 137 Example 138 SiO.sub.2 51 51 51 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 5 5 5 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 MgO/RO 0.73 0.73 0.73 N 10 10 10 Young's modulus E (GPa) 97 97 97 Coefficient of thermal expansion (ppm/ C.) 5.21 5.28 5.06 Liquidus temperature TL ( C.) 1230 1222 1193 Young's modulus parameter Y 0.96 0.96 0.97 Liquidus parameter L 9.7 9.7 9.9 Thermal expansion parameter C 1.01 1.01 1.00 Glass transition point ( C.) 709 707 709 Density (g/cm.sup.3) 2.99 3.01 2.91 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.74 0.62 0.76 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00020 TABLE 20 (mol %) Example 139 Example 140 Example 141 Example 142 SiO.sub.2 51 51 51 51 Al.sub.2O.sub.3 11 11 11 11 B.sub.2O.sub.3 4 4 4 6 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 13 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 0 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.45 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.38 0.37 MgO/RO 0.73 0.73 0.73 0.73 N 10 10 10 9 Young's modulus E (GPa) 99 99 99 95 Coefficient of thermal expansion (ppm/ C.) 5.18 5.25 5.02 4.82 Liquidus temperature TL ( C.) 1255 1246 1219 1209 Young's modulus parameter Y 0.98 0.97 0.98 0.92 Liquidus parameter L 10.0 10.0 10.2 10.0 Thermal expansion parameter C 1.01 1.01 0.99 0.94 Glass transition point ( C.) 718 716 718 705 Density (g/cm.sup.3) 3.00 3.02 2.92 2.80 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.73 0.61 0.75 0.78 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 143 Example 144 Example 145 SiO.sub.2 51 52 52 Al.sub.2O.sub.3 12 9 9 B.sub.2O.sub.3 5 5 5 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 11 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 0 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.43 0.43 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.35 0.35 MgO/RO 0.73 0.73 0.73 N 9 10 10 Young's modulus E (GPa) 96 97 96 Coefficient of thermal expansion (ppm/ C.) 4.79 5.23 5.30 Liquidus temperature TL ( C.) 1226 1232 1224 Young's modulus parameter Y 0.94 0.95 0.95 Liquidus parameter L 10.3 9.6 9.6 Thermal expansion parameter C 0.93 1.01 1.01 Glass transition point ( C.) 709 708 706 Density (g/cm.sup.3) 2.81 2.98 3.00 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.77 0.82 0.70 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00021 TABLE 21 (mol %) Example 146 Example 147 Example 148 Example 149 SiO.sub.2 52 52 52 52 Al.sub.2O.sub.3 9 10 10 10 B.sub.2O.sub.3 5 4 4 4 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 4 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.43 0.43 0.43 0.43 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.36 0.36 0.36 MgO/RO 0.73 0.73 0.73 0.73 N 10 10 10 10 Young's modulus E (GPa) 97 98 98 98 Coefficient of thermal expansion (ppm/ C.) 5.07 5.20 5.27 5.04 Liquidus temperature TL ( C.) 1202 1256 1247 1221 Young's modulus parameter Y 0.96 0.97 0.97 0.97 Liquidus parameter L 9.9 9.9 9.9 10.1 Thermal expansion parameter C 1.00 1.01 1.01 0.99 Glass transition point ( C.) 708 718 716 718 Density (g/cm.sup.3) 2.90 2.99 3.01 2.92 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.85 0.81 0.69 0.84 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 150 Example 151 Example 152 SiO.sub.2 52 49 49 Al.sub.2O.sub.3 11 10 10 B.sub.2O.sub.3 5 5 5 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 4 2 2 Li.sub.2O 1 2 Na.sub.2O 1 K.sub.2O 2 2 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 0 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 MgO/RO 0.73 0.79 0.79 N 9 13 12 Young's modulus E (GPa) 95 97 99 Coefficient of thermal expansion (ppm/ C.) 4.80 5.85 5.88 Liquidus temperature TL ( C.) 1223 1177 1180 Young's modulus parameter Y 0.93 0.95 0.96 Liquidus parameter L 10.2 9.7 9.6 Thermal expansion parameter C 0.93 1.13 1.06 Glass transition point ( C.) 709 696 696 Density (g/cm.sup.3) 2.80 2.82 2.83 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.86 0.60 0.64 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00022 TABLE 22 (mol %) Example 153 Example 154 Example 155 Example 156 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 5 5 5 5 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 2 3 3 3 Li.sub.2O 2 1 1 2 Na.sub.2O 1 1 K.sub.2O 1 2 1 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 0.37 MgO/RO 0.79 0.76 0.76 0.76 N 13 12 13 12 Young's modulus E (GPa) 101 97 98 101 Coefficient of thermal expansion (ppm/ C.) 5.62 5.87 5.62 5.65 Liquidus temperature TL ( C.) 1178 1179 1177 1180 Young's modulus parameter Y 0.99 0.94 0.97 0.98 Liquidus parameter L 9.3 9.9 9.6 9.6 Thermal expansion parameter C 1.13 1.05 1.13 1.06 Glass transition point ( C.) 696 693 693 693 Density (g/cm.sup.3) 2.83 2.87 2.87 2.88 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.64 0.60 0.60 0.63 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 157 Example 158 Example 159 SiO.sub.2 49 49 49 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 5 5 5 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 2 4 4 Li.sub.2O 2 1 Na.sub.2O 1 1 K.sub.2O 1 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.45 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 MgO/RO 0.76 0.73 0.73 N 12 12 12 Young's modulus E (GPa) 102 96 98 Coefficient of thermal expansion (ppm/ C.) 5.39 5.61 5.64 Liquidus temperature TL ( C.) 1185 1184 1184 Young's modulus parameter Y 1.01 0.95 0.96 Liquidus parameter L 9.3 9.9 9.9 Thermal expansion parameter C 1.14 1.12 1.05 Glass transition point ( C.) 703 699 694 Density (g/cm.sup.3) 2.88 2.90 2.91 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.63 0.56 0.60 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00023 TABLE 23 (mol %) Example 160 Example 161 Example 162 Example 163 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 5 5 6 6 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 2 2 Li.sub.2O 1 2 1 Na.sub.2O 1 2 K.sub.2O 1 2 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 0.37 MgO/RO 0.73 0.73 0.79 0.79 N 12 11 12 12 Young's modulus E (GPa) 100 102 95 96 Coefficient of thermal expansion (ppm/ C.) 5.38 5.41 5.43 5.72 Liquidus temperature TL ( C.) 1189 1191 1170 1170 Young's modulus parameter Y 0.99 1.00 0.96 0.94 Liquidus parameter L 9.6 9.5 9.4 9.7 Thermal expansion parameter C 1.13 1.08 1.18 1.03 Glass transition point ( C.) 704 704 699 693 Density (g/cm.sup.3) 2.91 2.92 2.81 2.82 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.60 0.63 0.59 0.62 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 164 Example 165 Example 166 SiO.sub.2 49 49 49 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 6 6 6 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 2 2 2 Li.sub.2O 1 1 2 Na.sub.2O 1 2 K.sub.2O 1 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 MgO/RO 0.79 0.79 0.79 N 13 12 12 Young's modulus E (GPa) 98 100 101 Coefficient of thermal expansion (ppm/ C.) 5.46 5.21 5.49 Liquidus temperature TL ( C.) 1170 1170 1170 Young's modulus parameter Y 0.97 1.00 0.98 Liquidus parameter L 9.4 9.1 9.3 Thermal expansion parameter C 4.11 1.18 1.03 Glass transition point ( C.) 693 704 693 Density (g/cm.sup.3) 2.82 2.82 2.83 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.62 0.62 0.66 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00024 TABLE 24 (mol %) Example 167 Example 168 Example 169 Example 170 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 6 6 6 6 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 2 3 3 3 Li.sub.2O 2 1 Na.sub.2O 1 1 2 K.sub.2O 1 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 0.37 MgO/RO 0.79 0.76 0.76 0.78 N 12 12 11 12 Young's modulus E (GPa) 102 95 97 98 Coefficient of thermal expansion (ppm/ C.) 5.24 5.46 5.20 5.49 Liquidus temperature TL ( C.) 1170 1172 1172 1171 Young's modulus parameter Y 1.01 0.95 0.98 0.96 Liquidus parameter L 9.0 9.7 9.4 9.6 Thermal expansion parameter C 1.11 1.10 1.18 1.03 Glass transition point ( C.) 704 694 704 689 Density (g/cm.sup.3) 2.83 2.86 2.86 2.87 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.66 0.59 0.59 0.62 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 171 Example 172 Example 173 SiO.sub.2 49 49 49 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 6 6 6 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 3 3 4 Li.sub.2O 1 2 Na.sub.2O 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 MgO/RO 0.76 0.76 0.73 N 12 11 11 Young's modulus E (GPa) 100 102 95 Coefficient of thermal expansion (ppm/ C.) 5.23 5.26 5.48 Liquidus temperature TL ( C.) 1172 1172 1174 Young's modulus parameter Y 0.99 1.00 0.94 Liquidus parameter L 9.3 9.3 9.9 Thermal expansion parameter C 1.11 1.04 1.03 Glass transition point ( C.) 699 699 695 Density (g/cm.sup.3) 2.67 2.88 2.91 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.62 0.66 0.59 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00025 TABLE 25 (mol %) Example 174 Example 175 Example 176 Example 177 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 6 6 7 7 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 4 2 2 Li.sub.2O 1 Na.sub.2O 1 1 2 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.36 0.36 MgO/RO 0.73 0.73 0.79 0.79 N 11 11 12 11 Young's modulus E (GPa) 97 100 95 97 Coefficient of thermal expansion (ppm/ C.) 5.22 5.25 5.30 5.05 Liquidus temperature TL ( C.) 1174 1174 1156 1156 Young's modulus parameter Y 0.96 0.97 0.95 0.98 Liquidus parameter L 9.6 9.6 9.5 9.2 Thermal expansion parameter C 1.10 1.03 1.08 1.16 Glass transition point ( C.) 705 700 694 705 Density (g/cm.sup.3) 2.91 2.92 2.82 2.82 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.59 0.62 0.61 0.61 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 178 Example 179 Example 180 SiO.sub.2 49 49 49 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 7 7 7 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 2 2 2 Li.sub.2O 1 1 Na.sub.2O 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.38 0.36 MgO/RO 0.79 0.79 0.79 N 12 12 11 Young's modulus E (GPa) 98 100 102 Coefficient of thermal expansion (ppm/ C.) 5.33 5.08 5.11 Liquidus temperature TL ( C.) 1156 1157 1156 Young's modulus parameter Y 0.96 0.99 1.00 Liquidus parameter L 9.4 9.1 9.1 Thermal expansion parameter C 1.01 1.09 1.01 Glass transition point ( C.) 689 700 700 Density (g/cm.sup.3) 2.83 2.83 2.84 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.65 0.65 0.68 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00026 TABLE 26 (mol %) Example 181 Example 182 Example 183 Example 184 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 10 10 10 11 B.sub.2O.sub.3 7 7 7 5 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 3 3 3 2 Li.sub.2O 1 Na.sub.2O 1 1 K.sub.2O 1 2 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 0.38 MgO/RO 0.76 0.76 0.76 0.79 N 11 11 11 12 Young's modulus E (GPa) 95 97 100 95 Coefficient of thermal expansion (ppm/ C.) 5.32 5.07 5.10 5.66 Liquidus temperature TL ( C.) 1157 1158 1158 1178 Young's modulus parameter Y 0.94 0.97 0.98 0.95 Liquidus parameter L 9.7 9.4 9.4 10.0 Thermal expansion parameter C 1.00 1.08 1.01 1.09 Glass transition point ( C.) 690 699 696 703 Density (g/cm.sup.3) 2.86 2.86 2.87 2.82 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.61 0.81 0.65 0.58 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 185 Example 186 Example 187 SiO.sub.2 49 49 49 Al.sub.2O.sub.3 11 11 11 B.sub.2O.sub.3 5 5 5 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 2 2 2 Li.sub.2O 1 1 Na.sub.2O 2 1 K.sub.2O 1 2 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 3 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.38 MgO/RO 0.79 0.79 0.79 N 12 12 13 Young's modulus E (GPa) 97 98 99 Coefficient of thermal expansion (ppm/ C.) 5.40 5.69 5.43 Liquidus temperature TL ( C.) 1178 1177 1176 Young's modulus parameter Y 0.98 0.96 0.99 Liquidus parameter L 9.7 9.9 9.6 Thermal expansion parameter C 1.17 1.02 1.10 Glass transition point ( C.) 703 696 696 Density (g/cm.sup.3) 2.82 2.83 2.83 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.58 0.62 0.62 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00027 TABLE 27 (mol %) Example 188 Example 189 Example 190 Example 191 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 11 11 11 11 B.sub.2O.sub.3 5 5 5 5 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 2 2 2 3 Li.sub.2O 1 2 2 Na.sub.2O 2 1 K.sub.2O 1 2 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.38 0.38 MgO/RO 0.79 0.79 0.79 0.76 N 12 12 12 11 Young's modulus E (GPa) 101 102 103 95 Coefficient of thermal expansion (ppm/ C.) 5.17 5.46 5.20 5.68 Liquidus temperature TL ( C.) 1183 1178 1183 1180 Young's modulus parameter Y 1.01 1.00 1.02 0.94 Liquidus parameter L 9.3 9.6 9.3 10.2 Thermal expansion parameter C 1.18 1.03 1.11 1.02 Glass transition point ( C.) 707 696 707 698 Density (g/cm.sup.3) 2.83 2.84 2.84 2.87 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.62 0.65 0.65 0.58 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 192 Example 193 Example 194 SiO.sub.2 49 49 49 Al.sub.2O.sub.3 11 11 11 B.sub.2O.sub.3 5 5 5 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 3 3 3 Li.sub.2O 1 Na.sub.2O 1 2 K.sub.2O 1 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.38 MgO/RO 0.76 0.76 0.76 N 12 11 12 Young's modulus E (GPa) 97 98 99 Coefficient of thermal expansion (ppm/ C.) 5.42 5.17 5.45 Liquidus temperature TL ( C.) 1178 1186 1178 Young's modulus parameter Y 0.96 0.99 0.97 Liquidus parameter L 9.9 9.6 9.9 Thermal expansion parameter C 1.10 1.17 1.02 Glass transition point ( C.) 698 709 693 Density (g/cm.sup.3) 2.87 2.87 2.88 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.58 0.58 0.62 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00028 TABLE 28 (mol %) Example 195 Example 196 Example 197 Example 198 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 11 11 11 11 B.sub.2O.sub.3 5 5 5 5 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 3 3 4 4 Li.sub.2O 1 2 Na.sub.2O 1 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.46 0.46 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.38 0.38 MgO/RO 0.76 0.76 0.73 0.73 N 12 11 11 11 Young's modulus E (GPa) 101 103 97 98 Coefficient of thermal expansion (ppm/ C.) 5.20 5.23 5.44 5.19 Liquidus temperature TL ( C.) 1183 1185 1184 1189 Young's modulus parameter Y 1.00 1.01 0.95 0.98 Liquidus parameter L 9.6 9.5 10.2 9.9 Thermal expansion parameter C 1.10 1.03 1.02 1.10 Glass transition point ( C.) 703 703 699 709 Density (g/cm.sup.3) 2.88 2.89 2.92 2.92 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.62 0.65 0.58 0.58 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 199 Example 200 Example 201 SiO.sub.2 49 49 49 Al.sub.2O.sub.3 11 11 11 B.sub.2O.sub.3 5 6 6 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 4 2 2 Li.sub.2O 1 Na.sub.2O 1 K.sub.2O 2 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.38 MgO/RO 0.73 0.79 0.79 N 11 11 12 Young's modulus E (GPa) 101 95 97 Coefficient of thermal expansion (ppm/ C.) 5.22 5.53 5.27 Liquidus temperature TL ( C.) 1189 1167 1168 Young's modulus parameter Y 0.99 0.94 0.96 Liquidus parameter L 9.8 10.0 9.7 Thermal expansion parameter C 1.03 0.99 1.07 Glass transition point ( C.) 704 699 699 Density (g/cm.sup.3) 2.93 2.83 2.83 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.62 0.61 0.61 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00029 TABLE 29 (mol %) Example 202 Example 203 Example 204 Example 205 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 11 11 11 11 B.sub.2O.sub.3 6 6 6 6 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 2 2 2 2 Li.sub.2O 1 1 2 Na.sub.2O 2 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.38 0.38 MgO/RO 0.79 0.79 0.79 0.79 N 11 12 12 11 Young's modulus E (GPa) 98 99 101 103 Coefficient of thermal expansion (ppm/ C.) 5.01 5.30 5.04 5.07 Liquidus temperature TL ( C.) 1168 1168 1169 1168 Young's modulus parameter Y 0.99 0.97 1.00 1.01 Liquidus parameter L 9.4 9.6 9.3 9.3 Thermal expansion parameter C 1.15 1.00 1.08 1.01 Glass transition point ( C.) 710 693 704 704 Density (g/cm.sup.3) 2.83 2.84 2.84 2.85 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.61 0.64 0.64 0.68 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 206 Example 207 Example 208 SiO.sub.2 49 49 49 Al.sub.2O.sub.3 11 11 11 B.sub.2O.sub.3 6 6 6 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 3 3 3 Li.sub.2O 1 Na.sub.2O 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.38 MgO/RO 0.76 0.76 0.76 N 11 11 11 Young's modulus E (GPa) 97 98 101 Coefficient of thermal expansion (ppm/ C.) 5.29 5.03 5.07 Liquidus temperature TL ( C.) 1169 1170 1170 Young's modulus parameter Y 0.95 0.98 0.99 Liquidus parameter L 10.0 9.6 9.6 Thermal expansion parameter C 1.00 1.07 1.00 Glass transition point ( C.) 695 705 700 Density (g/cm.sup.3) 2.87 2.87 2.88 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.60 0.60 0.64 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00030 TABLE 30 (mol %) Example 209 Example 210 Example 211 Example 212 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 11 11 11 11 B.sub.2O.sub.3 7 7 7 7 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 2 2 2 3 Li.sub.2O 1 Na.sub.2O 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 0.37 MgO/RO 0.79 0.79 0.79 0.76 N 11 11 11 10 Young's modulus E (GPa) 96 98 101 98 Coefficient of thermal expansion (ppm/ C.) 5.14 4.88 4.91 4.90 Liquidus temperature TL ( C.) 1152 1153 1154 1154 Young's modulus parameter Y 0.95 0.98 0.99 0.97 Liquidus parameter L 9.7 9.4 9.4 9.7 Thermal expansion parameter C 0.97 1.05 0.98 0.98 Glass transition point ( C.) 695 705 701 700 Density (g/cm.sup.3) 2.83 2.83 2.84 2.88 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.63 0.63 0.67 0.63 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 213 Example 214 Example 215 SiO.sub.2 49 49 49 Al.sub.2O.sub.3 12 12 12 B.sub.2O.sub.3 5 5 5 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 2 2 2 Li.sub.2O Na.sub.2O 1 2 K.sub.2O 2 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14 14 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.39 0.39 0.39 MgO/RO 0.79 0.79 0.79 N 11 12 11 Young's modulus E (GPa) 96 98 99 Coefficient of thermal expansion (ppm/ C.) 5.49 5.24 4.98 Liquidus temperature TL ( C.) 1185 1181 1188 Young's modulus parameter Y 0.95 0.98 1.01 Liquidus parameter L 10.2 9.9 9.6 Thermal expansion parameter C 0.99 1.07 1.14 Glass transition point ( C.) 702 702 713 Density (g/cm.sup.3) 2.84 2.84 2.84 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.60 0.60 0.60 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00031 TABLE 31 (mol %) Example 216 Example 217 Example 218 Example 219 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 12 12 12 12 B.sub.2O.sub.3 5 5 5 5 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 2 2 2 3 Li.sub.2O 1 1 2 Na.sub.2O 1 K.sub.2O 1 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14 14 14 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.45 0.46 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.39 0.39 0.39 0.39 MgO/RO 0.79 0.79 0.79 0.76 N 12 12 11 11 Young's modulus E (GPa) 100 102 105 98 Coefficient of thermal expansion (ppm/ C.) 5.27 5.01 5.04 5.28 Liquidus temperature TL ( C.) 1183 1185 1189 1186 Young's modulus parameter Y 0.99 1.02 1.03 0.97 Liquidus parameter L 9.9 9.6 9.5 10.2 Thermal expansion parameter C 0.99 1.07 1.00 0.99 Glass transition point ( C.) 695 706 706 698 Density (g/cm.sup.3) 2.85 2.85 2.86 2.88 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.63 0.63 0.67 0.60 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 220 Example 221 Example 222 SiO.sub.2 49 49 49 Al.sub.2O.sub.3 12 12 12 B.sub.2O.sub.3 5 5 6 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 3 3 2 Li.sub.2O 1 Na.sub.2O 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14 14 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.46 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.39 0.39 0.38 MgO/RO 0.76 0.76 0.79 N 11 11 11 Young's modulus E (GPa) 99 102 98 Coefficient of thermal expansion (ppm/ C.) 5.00 5.03 5.11 Liquidus temperature TL ( C.) 1188 1190 1168 Young's modulus parameter Y 0.99 1.00 0.97 Liquidus parameter L 9.9 9.8 10.0 Thermal expansion parameter C 1.07 1.00 0.97 Glass transition point ( C.) 708 703 693 Density (g/cm.sup.3) 2.88 2.89 2.84 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.60 0.63 0.62 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00032 TABLE 32 (mol %) Example 223 Example 224 Example 225 Example 226 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 12 12 12 12 B.sub.2O.sub.3 6 6 6 7 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 2 2 3 2 Li.sub.2O 1 Na.sub.2O 1 K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14 14 14 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.46 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.38 0.38 MgO/RO 0.79 0.79 0.76 0.79 N 11 11 10 10 Young's modulus E (GPa) 99 102 99 99 Coefficient of thermal expansion (ppm/ C.) 4.85 4.88 4.87 4.72 Liquidus temperature TL ( C.) 1168 1168 1170 1151 Young's modulus parameter Y 0.99 1.00 0.98 0.98 Liquidus parameter L 9.7 9.6 9.9 9.7 Thermal expansion parameter C 1.05 0.97 0.97 0.95 Glass transition point ( C.) 710 704 705 705 Density (g/cm.sup.3) 2.84 2.85 2.89 2.84 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.62 0.66 0.62 0.65 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 227 Example 228 Example 229 SiO.sub.2 50 50 50 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 5 5 5 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 2 2 2 Li.sub.2O 1 1 Na.sub.2O 2 1 K.sub.2O 1 2 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.43 0.43 0.43 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 MgO/RO 0.79 0.79 0.79 N 12 12 13 Young's modulus E (GPa) 96 97 98 Coefficient of thermal expansion (ppm/ C.) 5.42 5.70 5.45 Liquidus temperature TL ( C.) 1191 1192 1190 Young's modulus parameter Y 0.97 0.95 0.98 Liquidus parameter L 9.6 9.8 9.5 Thermal expansion parameter C 1.17 1.02 1.10 Glass transition point ( C.) 702 696 696 Density (g/cm.sup.3) 2.81 2.82 2.82 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.66 0.70 0.70 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00033 TABLE 33 (mol %) Example 230 Example 231 Example 232 Example 233 SiO.sub.2 50 50 50 50 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 5 5 5 5 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 2 2 2 3 Li.sub.2O 1 2 2 Na.sub.2O 2 1 1 K.sub.2O 1 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.43 0.43 0.43 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 0.37 MgO/RO 0.79 0.79 0.79 0.76 N 12 12 12 12 Young's modulus E (GPa) 100 101 103 96 Coefficient of thermal expansion (ppm/ C.) 5.19 5.48 5.22 5.44 Liquidus temperature TL ( C.) 1197 1193 1197 1190 Young's modulus parameter Y 1.00 0.99 1.01 0.95 Liquidus parameter L 9.2 9.5 9.2 9.8 Thermal expansion parameter C 1.18 1.03 1.11 1.10 Glass transition point ( C.) 707 696 707 698 Density (g/cm.sup.3) 2.82 2.83 2.83 2.86 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.70 0.74 0.74 0.66 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 234 Example 235 Example 236 SiO.sub.2 50 50 50 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 5 5 5 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 3 3 3 Li.sub.2O 1 1 Na.sub.2O 2 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 MgO/RO 0.76 0.76 0.76 N 11 12 12 Young's modulus E (GPa) 97 98 100 Coefficient of thermal expansion (ppm/ C.) 5.18 5.47 5.21 Liquidus temperature TL ( C.) 1197 1191 1197 Young's modulus parameter Y 0.98 0.96 0.99 Liquidus parameter L 9.5 9.8 9.5 Thermal expansion parameter C 1.18 1.03 1.10 Glass transition point ( C.) 708 693 703 Density (g/cm.sup.3) 2.86 2.87 2.87 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.66 0.70 0.70 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00034 TABLE 34 (mol %) Example 237 Example 238 Example 239 Example 240 SiO.sub.2 50 50 50 50 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 5 5 5 5 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 3 4 4 4 Li.sub.2O 2 1 Na.sub.2O 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 0.37 MgO/RO 0.76 0.73 0.73 0.73 N 11 11 11 11 Young's modulus E (GPa) 103 96 97 100 Coefficient of thermal expansion (ppm/ C.) 5.24 5.46 5.20 5.23 Liquidus temperature TL ( C.) 1198 1195 1200 1202 Young's modulus parameter Y 1.00 0.94 0.97 0.98 Liquidus parameter L 9.4 10.1 9.8 9.7 Thermal expansion parameter C 1.03 1.02 1.10 1.03 Glass transition point ( C.) 703 699 709 703 Density (g/cm.sup.3) 2.88 2.91 2.91 2.92 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.74 0.66 0.66 0.70 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 241 Example 242 Example 243 SiO.sub.2 50 50 50 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 6 6 6 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 2 2 2 Li.sub.2O 1 Na.sub.2O 1 2 K.sub.2O 1 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.43 0.43 0.43 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 MgO/RO 0.79 0.79 0.79 N 12 11 12 Young's modulus E (GPa) 96 97 98 Coefficient of thermal expansion (ppm/ C.) 5.29 5.03 5.32 Liquidus temperature TL ( C.) 1188 1188 1188 Young's modulus parameter Y 0.96 0.98 0.97 Liquidus parameter L 9.6 9.3 9.6 Thermal expansion parameter C 1.07 1.15 1.00 Glass transition point ( C.) 699 709 692 Density (g/cm.sup.3) 2.82 2.82 2.83 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.69 0.69 0.72 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00035 TABLE 35 (mol %) Example 244 Example 245 Example 246 Example 247 SiO.sub.2 50 50 50 50 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 6 6 6 6 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 2 2 3 3 Li.sub.2O 1 2 Na.sub.2O 1 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.43 0.43 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 0.36 MgO/RO 0.79 0.79 0.76 0.78 N 12 11 11 11 Young's modulus E (GPa) 100 102 96 97 Coefficient of thermal expansion (ppm/ C.) 5.06 5.09 5.31 5.05 Liquidus temperature TL ( C.) 1188 1188 1189 1188 Young's modulus parameter Y 0.99 1.00 0.94 0.97 Liquidus parameter L 9.2 9.2 9.9 9.6 Thermal expansion parameter C 1.08 1.01 1.00 1.08 Glass transition point ( C.) 704 704 694 704 Density (g/cm.sup.3) 2.83 2.84 2.86 2.86 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.72 0.76 0.69 0.69 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 248 Example 249 Example 250 SiO.sub.2 50 50 50 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 6 7 7 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 3 2 2 Li.sub.2O 1 Na.sub.2O 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.43 0.43 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 MgO/RO 0.76 0.79 0.79 N 11 11 11 Young's modulus E (GPa) 100 96 97 Coefficient of thermal expansion (ppm/ C.) 5.08 5.16 4.90 Liquidus temperature TL ( C.) 1189 1183 1182 Young's modulus parameter Y 0.98 0.94 0.97 Liquidus parameter L 9.5 9.6 9.3 Thermal expansion parameter C 1.01 0.97 1.05 Glass transition point ( C.) 699 694 705 Density (g/cm.sup.3) 2.88 2.82 2.82 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.72 0.71 0.71 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00036 TABLE 36 (mol %) Example 251 Example 252 Example 253 Example 254 SiO.sub.2 50 50 50 50 Al.sub.2O.sub.3 10 10 11 11 B.sub.2O.sub.3 7 7 5 5 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 2 3 2 2 Li.sub.2O 1 Na.sub.2O 1 K.sub.2O 2 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.43 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.38 0.38 MgO/RO 0.79 0.76 0.79 0.79 N 11 10 11 12 Young's modulus E (GPa) 100 97 95 97 Coefficient of thermal expansion (ppm/ C.) 4.93 4.92 5.51 5.25 Liquidus temperature TL ( C.) 1183 1183 1192 1190 Young's modulus parameter Y 0.98 0.96 0.94 0.97 Liquidus parameter L 9.3 9.6 10.1 9.8 Thermal expansion parameter C 0.98 0.98 0.99 1.07 Glass transition point ( C.) 700 699 703 703 Density (g/cm.sup.3) 2.83 2.87 2.83 2.83 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.75 0.71 0.68 0.68 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 255 Example 256 Example 257 SiO.sub.2 50 50 50 Al.sub.2O.sub.3 11 11 11 B.sub.2O.sub.3 5 5 5 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 2 2 2 Li.sub.2O 1 1 Na.sub.2O 2 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.38 MgO/RO 0.79 0.79 0.79 N 11 12 12 Young's modulus E (GPa) 98 99 101 Coefficient of thermal expansion (ppm/ C.) 5.00 5.28 5.03 Liquidus temperature TL ( C.) 1197 1191 1196 Young's modulus parameter Y 1.00 0.98 1.01 Liquidus parameter L 9.5 9.8 9.5 Thermal expansion parameter C 1.15 1.00 1.07 Glass transition point ( C.) 713 696 707 Density (g/cm.sup.3) 2.83 2.84 2.84 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.68 0.72 0.72 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00037 TABLE 37 (mol %) Example 258 Example 259 Example 260 Example 261 SiO.sub.2 50 50 50 50 Al.sub.2O.sub.3 11 11 11 11 B.sub.2O.sub.3 5 5 5 5 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 2 3 3 3 Li.sub.2O 2 1 Na.sub.2O 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.38 0.38 MgO/RO 0.79 0.76 0.76 0.78 N 11 11 11 11 Young's modulus E (GPa) 104 97 98 101 Coefficient of thermal expansion (ppm/ C.) 5.06 5.28 5.02 5.05 Liquidus temperature TL ( C.) 1198 1191 1197 1197 Young's modulus parameter Y 1.02 0.96 0.99 1.00 Liquidus parameter L 9.4 10.1 9.8 9.7 Thermal expansion parameter C 1.00 0.99 1.07 1.00 Glass transition point ( C.) 707 698 708 703 Density (g/cm.sup.3) 2.85 2.87 2.87 2.89 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.75 0.68 0.68 0.72 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 262 Example 263 Example 264 SiO.sub.2 50 50 50 Al.sub.2O.sub.3 11 11 11 B.sub.2O.sub.3 6 6 6 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 2 2 2 Li.sub.2O 1 Na.sub.2O 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 MgO/RO 0.79 0.79 0.79 N 11 11 11 Young's modulus E (GPa) 97 98 101 Coefficient of thermal expansion (ppm/ C.) 5.12 4.87 4.90 Liquidus temperature TL ( C.) 1186 1186 1187 Young's modulus parameter Y 0.96 0.99 1.00 Liquidus parameter L 9.9 9.6 9.5 Thermal expansion parameter C 0.97 1.05 0.98 Glass transition point ( C.) 699 710 704 Density (g/cm.sup.3) 2.83 2.83 2.84 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.79 0.71 0.74 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00038 TABLE 38 (mol %) Example 265 Example 266 Example 267 Example 268 SiO.sub.2 50 50 50 50 Al.sub.2O.sub.3 11 11 12 12 B.sub.2O.sub.3 6 7 5 5 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 3 2 2 2 Li.sub.2O Na.sub.2O 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 14 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.38 0.38 MgO/RO 0.76 0.79 0.79 0.79 N 10 10 11 11 Young's modulus E (GPa) 98 98 98 99 Coefficient of thermal expansion (ppm/ C.) 4.89 4.74 5.09 4.83 Liquidus temperature TL ( C.) 1187 1181 1197 1200 Young's modulus parameter Y 0.97 0.97 0.97 1.00 Liquidus parameter L 9.8 9.6 10.1 9.8 Thermal expansion parameter C 0.97 0.95 0.96 1.04 Glass transition point ( C.) 704 705 702 713 Density (g/cm.sup.3) 2.88 2.84 2.84 2.84 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.70 0.73 0.70 0.70 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 269 Example 270 Example 271 SiO.sub.2 50 50 50 Al.sub.2O.sub.3 12 12 12 B.sub.2O.sub.3 5 5 6 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 2 3 2 Li.sub.2O 1 Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14 14 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.45 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.38 0.38 MgO/RO 0.79 0.76 0.79 N 11 10 10 Young's modulus E (GPa) 102 99 99 Coefficient of thermal expansion (ppm/ C.) 4.86 4.86 4.70 Liquidus temperature TL ( C.) 1203 1203 1187 Young's modulus parameter Y 1.01 0.99 0.99 Liquidus parameter L 9.7 10.0 9.8 Thermal expansion parameter C 0.97 0.97 0.94 Glass transition point ( C.) 706 708 710 Density (g/cm.sup.3) 2.85 2.89 2.85 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.73 0.70 0.72 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00039 TABLE 39 (mol %) Example 272 Example 273 Example 274 Example 275 SiO.sub.2 51 51 51 51 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 5 5 5 5 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 2 2 2 2 Li.sub.2O 1 1 Na.sub.2O 1 2 1 K.sub.2O 1 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.43 0.43 0.43 0.43 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.38 0.38 0.36 MgO/RO 0.79 0.79 0.79 0.79 N 12 11 12 12 Young's modulus E (GPa) 96 97 98 100 Coefficient of thermal expansion (ppm/ C.) 5.27 5.01 5.30 5.04 Liquidus temperature TL ( C.) 1188 1195 1190 1195 Young's modulus parameter Y 0.96 0.99 0.97 1.00 Liquidus parameter L 9.8 9.4 9.7 9.4 Thermal expansion parameter C 1.07 1.15 1.00 1.08 Glass transition point ( C.) 702 713 696 707 Density (g/cm.sup.3) 2.62 2.82 2.83 2.83 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.76 0.76 0.80 0.80 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 276 Example 277 Example 278 SiO.sub.2 51 51 51 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 5 5 5 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 2 3 3 Li.sub.2O 2 Na.sub.2O 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.43 0.43 0.43 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.38 0.36 MgO/RO 0.79 0.76 0.76 N 11 11 11 Young's modulus E (GPa) 103 96 97 Coefficient of thermal expansion (ppm/ C.) 5.07 5.29 5.03 Liquidus temperature TL ( C.) 1196 1189 1194 Young's modulus parameter Y 1.01 0.95 0.98 Liquidus parameter L 9.3 10.0 9.7 Thermal expansion parameter C 1.01 0.99 1.07 Glass transition point ( C.) 707 698 708 Density (g/cm.sup.3) 2.84 2.87 2.87 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.84 0.76 0.76 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00040 TABLE 40 (mol %) Example 279 Example 280 Example 281 Example 282 SiO.sub.2 51 51 51 51 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 5 6 6 6 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 3 2 2 2 Li.sub.2O 1 1 Na.sub.2O 1 K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.43 0.43 0.43 0.43 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 0.36 MgO/RO 0.76 0.79 0.79 0.79 N 11 11 11 11 Young's modulus E (GPa) 100 96 97 100 Coefficient of thermal expansion (ppm/ C.) 5.06 5.14 4.88 4.91 Liquidus temperature TL ( C.) 1196 1187 1187 1187 Young's modulus parameter Y 0.99 0.95 0.98 0.99 Liquidus parameter L 9.6 9.8 9.5 9.4 Thermal expansion parameter C 1.00 0.97 1.05 0.98 Glass transition point ( C.) 703 699 709 704 Density (g/cm.sup.3) 2.88 2.82 2.82 2.83 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.80 0.79 0.79 0.82 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 283 Example 284 Example 285 SiO.sub.2 51 51 51 Al.sub.2O.sub.3 10 10 11 B.sub.2O.sub.3 6 7 5 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 3 2 2 Li.sub.2O Na.sub.2O K.sub.2O 1 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 12 12 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.43 0.43 0.43 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.38 0.37 MgO/RO 0.76 0.79 0.79 N 10 10 11 Young's modulus E (GPa) 97 97 97 Coefficient of thermal expansion (ppm/ C.) 4.90 4.75 5.11 Liquidus temperature TL ( C.) 1187 1182 1189 Young's modulus parameter Y 0.97 0.97 0.96 Liquidus parameter L 9.7 9.5 10.0 Thermal expansion parameter C 0.97 0.95 0.96 Glass transition point ( C.) 704 705 703 Density (g/cm.sup.3) 2.87 2.83 2.83 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.79 0.81 0.78 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00041 TABLE 41 (mol %) Example 286 Example 287 Example 288 Example 289 SiO.sub.2 51 51 51 51 Al.sub.2O.sub.3 11 11 11 11 B.sub.2O.sub.3 5 5 5 6 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 2 2 3 2 Li.sub.2O 1 Na.sub.2O 1 K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 13 13 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.43 0.43 0.44 0.43 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 0.37 MgO/RO 0.79 0.79 0.76 0.79 N 11 11 10 10 Young's modulus E (GPa) 99 101 99 98 Coefficient of thermal expansion (ppm/ C.) 4.85 4.88 4.87 4.72 Liquidus temperature TL ( C.) 1194 1195 1195 1185 Young's modulus parameter Y 0.99 1.00 0.98 0.98 Liquidus parameter L 9.7 9.6 10.0 9.7 Thermal expansion parameter C 1.04 0.97 0.97 0.94 Glass transition point ( C.) 713 707 708 710 Density (g/cm.sup.3) 2.83 2.84 2.88 2.84 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.78 0.82 0.78 0.81 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 290 Example 291 Example 292 SiO.sub.2 51 50 50 Al.sub.2O.sub.3 12 10 10 B.sub.2O.sub.3 5 6 6 MgO 22 21 21 CaO 2 2 2 SrO 2 2 2 BaO 2 3 3.5 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 2 1.5 TiO.sub.2 1 2 2 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 14 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.43 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.38 0.36 0.36 MgO/RO 0.79 0.75 0.74 N 10 10 10 Young's modulus E (GPa) 100 99 98 Coefficient of thermal expansion (ppm/ C.) 4.69 4.96 5.00 Liquidus temperature TL ( C.) 1201 1195 1190 Young's modulus parameter Y 1.00 0.98 0.97 Liquidus parameter L 10.0 10.0 10.0 Thermal expansion parameter C 0.94 0.99 0.99 Glass transition point ( C.) 713 705 705 Density (g/cm.sup.3) 2.85 2.89 2.90 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.80 0.94 0.85 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00042 TABLE 42 (mol %) Example 293 Example 294 Example 295 Example 296 SiO.sub.2 50 50 50 50 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 6 6 6 6 MgO 21 21 21 21 CaO 2 2 2 2 SrO 2 2 2 2 BaO 3.5 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 2 1 1.5 2 TiO.sub.2 1.5 2 1.5 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 0.36 MgO/RO 0.74 0.72 0.72 0.72 N 10 10 10 10 Young's modulus E (GPa) 99 97 98 98 Coefficient of thermal expansion (ppm/ C.) 5.02 5.04 5.07 5.09 Liquidus temperature TL ( C.) 1194 1190 1189 1193 Young's modulus parameter Y 0.98 0.96 0.96 0.97 Liquidus parameter L 10.0 10.0 10.0 9.9 Thermal expansion parameter C 1.00 1.00 1.00 1.00 Glass transition point ( C.) 705 706 706 705 Density (g/cm.sup.3) 2.91 2.91 2.92 2.93 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.88 0.76 0.79 0.83 Transmittance (%) @1064 nm, 0.7 mmt 80 80< 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 297 Example 298 Example 299 SiO.sub.2 50 50 50 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 6 6 6 MgO 21.5 21.5 21.5 CaO 2 2 2 SrO 2 2 2 BaO 3 3 3.5 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1.5 2 1 TiO.sub.2 2 1.5 2 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 MgO/RO 0.75 0.75 0.74 N 10 10 10 Young's modulus E (GPa) 99 99 98 Coefficient of thermal expansion (ppm/ C.) 4.95 4.97 4.99 Liquidus temperature TL ( C.) 1193 1196 1192 Young's modulus parameter Y 0.98 0.98 0.96 Liquidus parameter L 9.9 9.9 10.0 Thermal expansion parameter C 0.98 0.99 0.99 Glass transition point ( C.) 705 705 705 Density (g/cm.sup.3) 2.88 2.89 2.89 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.87 0.90 0.78 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00043 TABLE 43 (mol %) Example 300 Example 301 Example 302 Example 303 SiO.sub.2 50 50 50 50 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 6 6 6 6 MgO 21.5 21.5 21.5 21.5 CaO 2 2 2 2 SrO 2 2 2 2 BaO 3.5 3.5 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1.5 2 0.5 1 TiO.sub.2 1.5 1 2 1.5 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 0.36 MgO/RO 0.74 0.74 0.73 0.73 N 10 10 10 10 Young's modulus E (GPa) 98 99 97 97 Coefficient of thermal expansion (ppm/ C.) 5.01 5.04 5.03 5.06 Liquidus temperature TL ( C.) 1191 1195 1193 1192 Young's modulus parameter Y 0.97 0.98 0.95 0.98 Liquidus parameter L 9.9 9.8 10.0 9.9 Thermal expansion parameter C 0.99 1.00 0.99 1.00 Glass transition point ( C.) 705 704 705 706 Density (g/cm.sup.3) 2.90 2.91 2.90 2.91 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.81 0.85 0.69 0.72 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 304 Example 305 Example 306 SiO.sub.2 50 50 50 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 6 6 6 MgO 21.5 21.5 22 CaO 2 2 2 SrO 2 2 2 BaO 4 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1.5 2 1 TiO.sub.2 1 0.5 2 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 MgO/RO 0.73 0.73 0.76 N 10 10 10 Young's modulus E (GPa) 98 98 98 Coefficient of thermal expansion (ppm/ C.) 5.08 5.11 4.94 Liquidus temperature TL ( C.) 1189 1197 1192 Young's modulus parameter Y 0.97 0.97 0.97 Liquidus parameter L 9.9 9.8 9.9 Thermal expansion parameter C 1.00 1.01 0.98 Glass transition point ( C.) 705 710 705 Density (g/cm.sup.3) 2.92 2.93 2.88 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.76 0.79 0.80 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00044 TABLE 44 (mol %) Example 307 Example 308 Example 309 Example 310 SiO.sub.2 50 50 50 50 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 6 6 6 6 MgO 22 22 22 22 CaO 2 2 2 2 SrO 2 2 2 2 BaO 3 3 3.5 3.5 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1.5 2 0.5 1 TiO.sub.2 1.5 1 2 1.5 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 0.36 MgO/RO 0.76 0.76 0.75 0.75 N 10 10 10 10 Young's modulus E (GPa) 99 99 97 98 Coefficient of thermal expansion (ppm/ C.) 4.96 4.99 4.98 5.01 Liquidus temperature TL ( C.) 1191 1195 1193 1191 Young's modulus parameter Y 0.98 0.99 0.96 0.97 Liquidus parameter L 9.8 9.8 9.9 9.8 Thermal expansion parameter C 0.99 0.99 0.99 0.99 Glass transition point ( C.) 705 704 705 705 Density (g/cm.sup.3) 2.88 2.89 2.89 2.89 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.84 0.87 0.71 0.74 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 311 Example 312 Example 313 SiO.sub.2 50 50 50 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 6 6 6 MgO 22 22 22 CaO 2 2 2 SrO 2 2 2 BaO 3.5 3.5 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1.5 2 0.5 TiO.sub.2 1 0.5 1.5 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.36 0.36 MgO/RO 0.75 0.75 0.73 N 10 10 10 Young's modulus E (GPa) 98 99 97 Coefficient of thermal expansion (ppm/ C.) 5.03 5.06 5.05 Liquidus temperature TL ( C.) 1189 1196 1192 Young's modulus parameter Y 0.97 0.98 0.95 Liquidus parameter L 9.8 9.7 9.9 Thermal expansion parameter C 1.00 1.00 1.00 Glass transition point ( C.) 704 710 705 Density (g/cm.sup.3) 2.90 2.91 2.90 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.78 0.81 0.65 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00045 TABLE 45 (mol %) Example 314 Example 315 Example 316 Example 317 SiO.sub.2 50 50 50 50 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 6 6 6 6 MgO 22 22.5 22.5 22.5 CaO 2 2 2 2 SrO 2 2 2 2 BaO 4 3 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1.5 0.5 1 1.5 TiO.sub.2 0.5 2 1.5 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.37 0.37 0.37 MgO/RO 0.73 0.76 0.76 0.76 N 10 10 10 10 Young's modulus E (GPa) 98 98 98 99 Coefficient of thermal expansion (ppm/ C.) 5.10 4.93 4.95 4.98 Liquidus temperature TL ( C.) 1190 1193 1192 1190 Young's modulus parameter Y 0.97 0.96 0.97 0.98 Liquidus parameter L 9.7 9.8 9.8 9.7 Thermal expansion parameter C 1.00 0.98 0.98 0.99 Glass transition point ( C.) 710 705 705 704 Density (g/cm.sup.3) 2.92 2.87 2.88 2.89 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.72 0.73 0.77 0.80 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 318 Example 319 Example 320 SiO.sub.2 50 50 50 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 6 6 6 MgO 22.5 22.5 22.5 CaO 2 2 2 SrO 2 2 2 BaO 3 3.5 3.5 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 2 0.5 1 TiO.sub.2 0.5 1.5 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 MgO/RO 0.76 0.75 0.75 N 10 10 10 Young's modulus E (GPa) 99 97 98 Coefficient of thermal expansion (ppm/ C.) 5.01 5.00 5.02 Liquidus temperature TL ( C.) 1197 1193 1190 Young's modulus parameter Y 0.99 0.96 0.97 Liquidus parameter L 9.6 9.8 9.7 Thermal expansion parameter C 0.99 0.99 0.99 Glass transition point ( C.) 709 705 704 Density (g/cm.sup.3) 2.89 2.89 2.90 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30< 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.84 0.67 0.71 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00046 TABLE 46 (mol %) Example 321 Example 322 Example 323 Example 324 SiO.sub.2 50 50 50 50 Al.sub.2O.sub.3 10 10 10 10 B.sub.2O.sub.3 6 6 6 6 MgO 22.5 22.5 22.5 23 CaO 2 2 2 2 SrO 2 2 2 2 BaO 3.5 4 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1.5 0.5 1 0.5 TiO.sub.2 0.5 1 0.5 1.5 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.45 0.45 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 0.37 MgO/RO 0.75 0.74 0.74 0.77 N 10 10 10 10 Young's modulus E (GPa) 98 97 97 98 Coefficient of thermal expansion (ppm/ C.) 5.05 5.06 5.09 4.95 Liquidus temperature TL ( C.) 1191 1191 1191 1194 Young's modulus parameter Y 0.97 0.95 0.96 0.97 Liquidus parameter L 9.7 9.7 9.7 9.7 Thermal expansion parameter C 1.00 1.00 1.00 0.98 Glass transition point ( C.) 709 705 710 705 Density (g/cm.sup.3) 2.90 2.90 2.91 2.87 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.74 0.62 0.65 0.70 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 325 Example 326 Example 327 SiO.sub.2 50 50 50 Al.sub.2O.sub.3 10 10 10 B.sub.2O.sub.3 6 6 6 MgO 23 23 23 CaO 2 2 2 SrO 2 2 2 BaO 3 3 3.5 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1.5 0.5 TiO.sub.2 1 0.5 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.37 MgO/RO 0.77 0.77 0.75 N 10 10 10 Young's modulus E (GPa) 98 99 97 Coefficient of thermal expansion (ppm/ C.) 4.97 5.00 5.01 Liquidus temperature TL ( C.) 1191 1193 1192 Young's modulus parameter Y 0.97 0.98 0.96 Liquidus parameter L 9.6 9.6 9.7 Thermal expansion parameter C 0.99 0.99 0.99 Glass transition point ( C.) 704 709 704 Density (g/cm.sup.3) 2.88 2.89 2.89 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.73 0.77 0.64 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00047 TABLE 47 (mol %) Example 328 Example 329 Example 330 Example 331 SiO.sub.2 50 50 48 48 Al.sub.2O.sub.3 10 10 9 9 B.sub.2O.sub.3 6 6 3 4 MgO 23 23 19 19 CaO 2 2 4 4 SrO 2 2 3 3 BaO 3.5 4 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 6 P.sub.2O.sub.5 ZrO.sub.2 1 0.5 1 1 TiO.sub.2 0.5 0.5 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 12 12 11 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.48 0.48 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.35 0.35 MgO/RO 0.75 0.74 0.53 0.54 N 10 10 11 11 Young's modulus E (GPa) 98 97 99 99 Coefficient of thermal expansion (ppm/ C.) 5.04 5.08 5.50 5.50 Liquidus temperature TL ( C.) 1192 1191 1217 1219 Young's modulus parameter Y 0.97 0.95 0.99 0.99 Liquidus parameter L 9.6 9.6 9.7 9.3 Thermal expansion parameter C 1.00 1.00 1.10 1.10 Glass transition point ( C.) 709 710 719 714 Density (g/cm.sup.3) 2.90 2.91 3.14 3.17 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.67 0.58 0.28 0.28 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 332 Example 333 Example 334 SiO.sub.2 49 48 49 Al.sub.2O.sub.3 9 8 9 B.sub.2O.sub.3 3 4 4 MgO 18 20 18 CaO 5 5 4 SrO 4 3 3 BaO 3 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 5 6 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 11 10 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.48 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.35 0.34 MgO/RO 0.51 0.56 0.53 N 11 11 11 Young's modulus E (GPa) 99 99 98 Coefficient of thermal expansion (ppm/ C.) 5.51 5.51 5.51 Liquidus temperature TL ( C.) 1216 1216 1216 Young's modulus parameter Y 0.98 0.99 0.98 Liquidus parameter L 9.6 9.4 9.4 Thermal expansion parameter C 1.11 1.11 1.08 Glass transition point ( C.) 715 712 711 Density (g/cm.sup.3) 3.09 3.07 3.18 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.34 0.33 0.22 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00048 TABLE 48 (mol %) Example 335 Example 336 Example 337 Example 338 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 9 9 8 8 B.sub.2O.sub.3 3 4 3 4 MgO 18 18 19 20 CaO 5 5 4 4 SrO 3 3 4 3 BaO 4 3 3 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 5 6 4 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 11 11 10 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.47 0.47 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.34 0.34 0.35 MgO/RO 0.51 0.53 0.53 0.57 N 11 11 11 11 Young's modulus E (GPa) 98 98 99 98 Coefficient of thermal expansion (ppm/ C.) 5.51 5.51 5.51 5.51 Liquidus temperature TL ( C.) 1214 1218 1218 1215 Young's modulus parameter Y 0.98 0.98 1.00 0.97 Liquidus parameter L 9.8 9.4 9.4 9.6 Thermal expansion parameter C 1.11 1.10 1.11 1.10 Glass transition point ( C.) 719 714 714 713 Density (g/cm.sup.3) 3.11 3.14 3.11 3.07 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.34 0.34 0.36 0.43 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 339 Example 340 Example 343 SiO.sub.2 47 49 47 Al.sub.2O.sub.3 9 8 9 B.sub.2O.sub.3 4 3 4 MgO 19 19 19 CaO 4 4 4 SrO 4 3 3 BaO 3 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 6 6 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 11 10 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.49 0.47 0.49 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.34 0.35 MgO/RO 0.53 0.53 0.53 N 11 11 11 Young's modulus E (GPa) 100 98 99 Coefficient of thermal expansion (ppm/ C.) 5.51 5.52 5.52 Liquidus temperature TL ( C.) 1219 1214 1216 Young's modulus parameter Y 1.00 0.98 0.99 Liquidus parameter L 9.3 9.6 9.6 Thermal expansion parameter C 1.12 1.11 1.11 Glass transition point ( C.) 712 717 715 Density (g/cm.sup.3) 3.12 3.13 3.14 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.20 0.36 0.20 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00049 TABLE 49 (mol %) Example 342 Example 343 Example 344 Example 345 SiO.sub.2 49 48 48 49 Al.sub.2O.sub.3 8 9 9 9 B.sub.2O.sub.3 4 4 4 4 MgO 19 18 18 18 CaO 4 5 5 4 SrO 3 4 3 4 BaO 3 3 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 5 5 4 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 10 11 11 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.48 0.48 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.34 0.34 0.34 MgO/RO 0.54 0.51 0.51 0.53 N 11 11 11 11 Young's modulus E (GPa) 98 99 98 97 Coefficient of thermal expansion (ppm/ C.) 5.52 5.52 5.53 5.53 Liquidus temperature TL ( C.) 1216 1216 1215 1218 Young's modulus parameter Y 0.98 0.99 0.98 0.97 Liquidus parameter L 9.2 9.5 9.7 9.7 Thermal expansion parameter C 1.10 1.12 1.11 1.11 Glass transition point ( C.) 712 711 715 712 Density (g/cm.sup.3) 3.17 3.09 3.11 3.08 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.36 0.26 0.26 0.35 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 346 Example 347 Example 348 SiO.sub.2 48 49 49 Al.sub.2O.sub.3 8 9 9 B.sub.2O.sub.3 4 4 3 MgO 19 19 19 CaO 4 4 5 SrO 4 3 3 BaO 3 3 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 5 4 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 10 11 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.47 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.35 0.35 MgO/RO 0.53 0.56 0.54 N 11 11 11 Young's modulus E (GPa) 99 99 99 Coefficient of thermal expansion (ppm/ C.) 5.53 5.53 5.53 Liquidus temperature TL ( C.) 1217 1218 1216 Young's modulus parameter Y 0.99 0.98 0.98 Liquidus parameter L 9.3 9.4 9.8 Thermal expansion parameter C 1.12 1.08 1.11 Glass transition point ( C.) 710 711 719 Density (g/cm.sup.3) 3.11 3.16 3.08 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.28 0.26 0.38 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00050 TABLE 50 (mol %) Example 349 Example 350 Example 351 Example 352 SiO.sub.2 48 49 49 49 Al.sub.2O.sub.3 8 8 9 8 B.sub.2O.sub.3 4 4 3 3 MgO 19 18 18 20 CaO 4 5 5 4 SrO 3 4 3 3 BaO 4 3 3 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 5 6 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 10 10 11 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.47 0.47 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.33 0.34 0.35 MgO/RO 0.53 0.51 0.51 0.56 N 11 11 11 11 Young's modulus E (GPa) 98 98 99 99 Coefficient of thermal expansion (ppm/ C.) 5.53 5.54 5.54 5.54 Liquidus temperature TL ( C.) 1214 1211 1220 1217 Young's modulus parameter Y 0.98 0.98 0.99 0.99 Liquidus parameter L 9.5 9.4 9.5 9.6 Thermal expansion parameter C 1.11 1.12 1.10 1.11 Glass transition point ( C.) 713 709 718 717 Density (g/cm.sup.3) 3.13 3.08 3.18 3.10 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.84 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.29 0.34 0.31 0.40 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 353 Example 354 Example 355 SiO.sub.2 49 47 48 Al.sub.2O.sub.3 8 9 9 B.sub.2O.sub.3 4 4 4 MgO 18 20 19 CaO 5 4 5 SrO 3 3 4 BaO 4 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 5 4 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 10 11 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.49 0.48 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.33 0.36 0.35 MgO/RO 0.51 0.56 0.54 N 11 11 11 Young's modulus E (GPa) 97 99 99 Coefficient of thermal expansion (ppm/ C.) 5.54 5.54 5.55 Liquidus temperature TL ( C.) 1210 1220 1219 Young's modulus parameter Y 0.97 0.99 0.99 Liquidus parameter L 9.6 9.6 9.5 Thermal expansion parameter C 1.19 1.11 1.12 Glass transition point ( C.) 713 715 711 Density (g/cm.sup.3) 3.10 3.11 3.06 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8% 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.34 0.24 0.30 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00051 TABLE 51 (mol %) Example 356 Example 357 Example 358 Example 359 SiO.sub.2 48 48 48 48 Al.sub.2O.sub.3 9 9 9 9 B.sub.2O.sub.3 3 4 3 4 MgO 18 19 18 18 CaO 5 5 5 5 SrO 4 3 3 3 BaO 3 4 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 4 6 6 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 11 11 11 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.48 0.48 0.48 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.35 0.35 0.34 MgO/RO 0.50 0.54 0.50 0.51 N 11 11 11 11 Young's modulus E (GPa) 99 98 99 99 Coefficient of thermal expansion (ppm/ C.) 5.55 5.55 5.55 5.58 Liquidus temperature TL ( C.) 1219 1215 1218 1219 Young's modulus parameter Y 1.00 0.98 0.99 0.99 Liquidus parameter L 9.5 9.7 9.8 9.3 Thermal expansion parameter C 1.12 1.11 1.12 1.11 Glass transition point ( C.) 716 715 719 714 Density (g/cm.sup.3) 3.13 3.08 3.14 3.18 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.24 0.30 0.24 0.24 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 360 Example 361 Example 362 SiO.sub.2 49 48 49 Al.sub.2O.sub.3 9 8 9 B.sub.2O.sub.3 3 4 4 MgO 18 20 18 CaO 4 4 4 SrO 4 3 4 BaO 4 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 5 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 11 10 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.48 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.35 0.34 MgO/RO 0.51 0.56 0.53 N 11 11 11 Young's modulus E (GPa) 98 98 98 Coefficient of thermal expansion (ppm/ C.) 5.56 5.56 5.56 Liquidus temperature TL ( C.) 1219 1218 1219 Young's modulus parameter Y 0.98 0.98 0.98 Liquidus parameter L 9.7 9.5 9.3 Thermal expansion parameter C 1.11 1.11 1.11 Glass transition point ( C.) 716 713 711 Density (g/cm.sup.3) 3.12 3.10 3.16 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.33 0.33 0.33 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00052 TABLE 52 (mol %) Example 363 Example 364 Example 365 Example 366 SiO.sub.2 49 49 49 49 Al.sub.2O.sub.3 9 8 8 8 B.sub.2O.sub.3 3 4 3 4 MgO 19 19 18 19 CaO 4 5 5 5 SrO 3 4 4 3 BaO 3 3 3 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 4 6 4 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 11 10 10 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.47 0.47 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.34 0.33 0.34 MgO/RO 0.54 0.54 0.50 0.54 N 11 11 11 11 Young's modulus E (GPa) 99 98 99 97 Coefficient of thermal expansion (ppm/ C.) 5.56 5.56 5.56 5.57 Liquidus temperature TL ( C.) 1219 1217 1214 1211 Young's modulus parameter Y 0.99 0.98 0.99 0.97 Liquidus parameter L 9.4 9.4 9.4 9.6 Thermal expansion parameter C 1.09 1.12 1.13 1.11 Glass transition point ( C.) 717 709 713 713 Density (g/cm.sup.3) 3.19 3.05 3.12 3.07 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.24 0.39 0.32 0.39 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 367 Example 368 Example 369 SiO.sub.2 47 49 47 Al.sub.2O.sub.3 9 8 9 B.sub.2O.sub.3 4 3 4 MgO 18 18 18 CaO 5 5 5 SrO 4 3 3 BaO 3 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 6 6 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 11 10 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.49 0.47 0.49 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.33 0.35 MgO/RO 0.50 0.50 0.50 N 11 11 11 Young's modulus E (GPa) 99 98 99 Coefficient of thermal expansion (ppm/ C.) 5.57 5.57 5.57 Liquidus temperature TL ( C.) 1216 1213 1216 Young's modulus parameter Y 0.99 0.98 0.98 Liquidus parameter L 9.4 9.7 9.6 Thermal expansion parameter C 1.13 1.12 1.12 Glass transition point ( C.) 711 717 715 Density (g/cm.sup.3) 3.12 3.13 3.14 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.16 0.32 0.16 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00053 TABLE 53 (mol %) Example 370 Example 371 Example 372 Example 373 SiO.sub.2 49 48 48 48 Al.sub.2O.sub.3 8 9 9 8 B.sub.2O.sub.3 4 4 3 4 MgO 18 19 19 18 CaO 5 4 5 5 SrO 3 3 3 4 BaO 3 3 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 6 5 6 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 10 11 11 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.48 0.48 0.48 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.33 0.35 0.35 0.33 MgO/RO 0.51 0.54 0.53 0.50 N 11 11 11 11 Young's modulus E (GPa) 98 99 99 98 Coefficient of thermal expansion (ppm/ C.) 5.57 5.58 5.58 5.58 Liquidus temperature TL ( C.) 1215 1218 1219 1215 Young's modulus parameter Y 0.98 0.99 0.99 0.99 Liquidus parameter L 9.2 9.3 9.8 9.3 Thermal expansion parameter C 1.11 1.10 1.12 1.13 Glass transition point ( C.) 712 712 719 709 Density (g/cm.sup.3) 3.17 3.19 3.12 3.11 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.32 0.16 0.28 0.24 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 374 Example 375 Example 376 SiO.sub.2 49 48 49 Al.sub.2O.sub.3 9 8 8 B.sub.2O.sub.3 4 4 4 MgO 18 18 18 CaO 5 5 4 SrO 3 3 5 BaO 3 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 6 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 11 10 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.48 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.33 0.33 MgO/RO 0.53 0.50 0.51 N 11 11 11 Young's modulus E (GPa) 98 98 98 Coefficient of thermal expansion (ppm/ C.) 5.58 5.58 5.58 Liquidus temperature TL ( C.) 1218 1214 1218 Young's modulus parameter Y 0.98 0.97 0.98 Liquidus parameter L 9.4 9.5 9.3 Thermal expansion parameter C 1.10 1.12 1.13 Glass transition point ( C.) 711 713 709 Density (g/cm.sup.3) 3.16 3.13 3.09 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.22 0.24 0.34 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00054 TABLE 54 (mol %) Example 377 Example 378 Example 379 Example 380 SiO.sub.2 49 49 47 49 Al.sub.2O.sub.3 8 8 9 8 B.sub.2O.sub.3 4 3 4 4 MgO 18 19 19 19 CaO 4 5 5 4 SrO 4 4 4 3 BaO 4 3 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 5 5 6 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 10 10 11 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.47 0.49 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.33 0.34 0.35 0.34 MgO/RO 0.51 0.53 0.53 0.54 N 11 11 11 11 Young's modulus E (GPa) 97 99 99 98 Coefficient of thermal 5.59 5.59 5.59 5.59 expansion (ppm/ C.) Liquidus temperature TL ( C.) 1215 1219 1220 1216 Young's modulus parameter Y 0.97 0.99 1.00 0.98 Liquidus parameter L 9.5 9.4 9.4 9.2 Thermal expansion parameter C 1.12 1.13 1.13 1.10 Glass transition point ( C.) 710 713 711 711 Density (g/cm.sup.3) 3.11 3.09 3.10 3.18 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Acid resistance parameter T 0.34 0.36 0.20 0.24 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination (mol %) Example 381 Example 382 Example 383 SiO.sub.2 49 47 49 Al.sub.2O.sub.3 8 9 8 B.sub.2O.sub.3 3 4 4 MgO 19 19 19 CaO 5 5 5 SrO 3 3 3 BaO 4 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 5 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.2 + rare earth oxide 10 11 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 3 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.49 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.35 0.34 MgO/RO 0.53 0.53 0.54 N 11 11 11 Young's modulus E (GPa) 98 99 98 Coefficient of thermal expansion (ppm/ C.) 5.59 5.59 5.60 Liquidus temperature TL ( C.) 1216 1217 1217 Young's modulus parameter Y 0.98 0.98 0.98 Liquidus parameter L 9.7 9.6 9.2 Thermal expansion parameter C 1.12 1.13 1.11 Glass transition point ( C.) 717 715 712 Density (g/cm.sup.3) 3.11 3.11 3.14 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 Acid resistance parameter T 0.36 0.20 0.36 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00055 TABLE 55 Example Example Example Example Example Example Example (mol %) 384 385 386 387 388 389 390 SiO.sub.2 48 48 49 49 49 47 49 Al.sub.2O.sub.3 8 8 9 8 8 9 8 B.sub.2O.sub.3 4 4 3 3 3 4 4 MgO 19 19 18 18 20 20 18 CaO 5 5 5 4 5 5 4 SrO 4 3 3 4 3 3 4 BaO 3 4 3 4 4 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 5 6 6 4 4 6 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 10 10 11 10 10 11 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.48 0.47 0.47 0.47 0.49 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.34 0.34 0.33 0.35 0.36 0.33 MgO/RO 0.53 0.53 0.51 0.50 0.56 0.56 0.51 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 98 98 99 98 98 99 98 Coefficient of thermal expansion (ppm/ C.) 5.61 5.61 5.61 5.62 5.62 5.62 5.62 Liquidus temperature TL ( C.) 1218 1215 1218 1217 1218 1220 1216 Young's modulus parameter Y 0.99 0.98 0.99 0.98 0.98 0.99 0.98 Liquidus parameter L 9.3 9.5 9.5 9.6 9.7 9.6 9.1 Thermal expansion parameter C 1.13 1.13 1.10 1.13 1.12 1.13 1.12 Glass transition point ( C.) 709 713 716 715 717 714 709 Density (g/cm.sup.3) 3.09 3.11 3.20 3.15 3.08 3.09 3.18 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.29 0.29 0.19 0.32 0.41 0.25 0.32 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00056 TABLE 56 Example Example Example Example Example Example Example (mol %) 391 392 393 394 395 396 397 SiO.sub.2 47 49 49 48 49 48 48 Al.sub.2O.sub.3 9 8 8 9 9 8 8 B.sub.2O.sub.3 3 4 3 4 4 4 4 MgO 19 18 19 18 18 18 20 CaO 5 4 5 5 4 4 5 SrO 3 3 3 3 4 4 3 BaO 4 4 3 3 3 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 6 6 6 5 6 4 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 10 10 11 11 10 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.49 0.47 0.47 0.48 0.47 0.48 0.48 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.33 0.34 0.34 0.34 0.33 0.35 MgO/RO 0.51 0.51 0.53 0.51 0.53 0.50 0.56 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 100 97 99 99 98 98 98 Coefficient of thermal expansion (ppm/ C.) 5.62 5.62 5.62 5.63 5.63 5.63 5.63 Liquidus temperature TL ( C.) 1220 1218 1219 1219 1219 1219 1217 Young's modulus parameter Y 1.00 0.97 0.99 0.98 0.98 0.98 0.98 Liquidus parameter L 9.7 9.4 9.3 9.3 9.3 9.4 9.5 Thermal expansion parameter C 1.13 1.11 1.12 1.11 1.11 1.13 1.13 Glass transition point ( C.) 719 713 717 712 710 711 713 Density (g/cm.sup.3) 3.15 3.20 3.18 3.19 3.17 3.14 3.08 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.18 0.32 0.34 0.12 0.21 0.24 0.33 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00057 TABLE 57 Example Example Example Example Example Example Example (mol %) 398 399 400 401 402 403 404 SiO.sub.2 48 48 49 49 47 48 49 Al.sub.2O.sub.3 8 8 8 7 8 9 7 B.sub.2O.sub.3 3 4 4 3 4 4 3 MgO 19 19 18 19 19 19 19 CaO 5 5 5 5 5 5 5 SrO 3 3 3 4 4 3 3 BaO 4 3 3 3 3 3 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 6 6 6 6 5 6 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 10 10 10 9 10 11 9 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.48 0.47 0.47 0.49 0.48 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.34 0.33 0.33 0.35 0.35 0.33 MgO/RO 0.51 0.53 0.51 0.51 0.51 0.54 0.51 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 99 99 98 98 99 99 98 Coefficient of thermal expansion (ppm/ C.) 5.64 5.64 5.64 5.65 5.65 5.65 5.65 Liquidus temperature TL ( C.) 1218 1217 1215 1211 1218 1219 1208 Young's modulus parameter Y 0.99 0.98 0.98 0.99 0.99 0.99 0.98 Liquidus parameter L 9.6 9.2 9.2 9.3 9.2 9.3 9.5 Thermal expansion parameter C 1.13 1.13 1.11 1.14 1.15 1.11 1.13 Glass transition point ( C.) 717 712 710 713 710 712 717 Density (g/cm.sup.3) 3.14 3.18 3.18 3.12 3.12 3.17 3.13 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.26 0.26 0.20 0.35 0.19 0.16 0.35 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00058 TABLE 58 Example Example Example Example Example Example Example (mol %) 405 406 407 408 409 410 411 SiO.sub.2 47 49 49 49 49 48 49 Al.sub.2O.sub.3 8 9 9 8 9 8 7 B.sub.2O.sub.3 4 3 3 4 3 3 3 MgO 19 18 18 19 18 19 20 CaO 5 4 4 5 4 5 5 SrO 3 4 3 3 5 4 4 BaO 4 3 4 3 3 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 6 6 5 5 5 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 2 2 2 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 10 11 11 10 11 10 9 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.49 0.47 0.47 0.47 0.47 0.48 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.34 0.34 0.34 0.34 0.35 0.34 MgO/RO 0.51 0.51 0.51 0.54 0.51 0.51 0.54 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 99 99 99 98 99 99 99 Coefficient of thermal expansion (ppm/ C.) 5.65 5.66 5.66 5.67 5.55 5.76 5.67 Liquidus temperature TL ( C.) 1216 1219 1219 1217 1225 1225 1214 Young's modulus parameter Y 0.98 0.99 0.98 0.98 1.00 0.99 0.99 Liquidus parameter L 9.5 9.3 9.6 9.2 9.5 9.5 9.3 Thermal expansion parameter C 1.14 1.11 1.11 1.11 1.12 1.16 1.14 Glass transition point ( C.) 713 715 717 710 714 714 713 Density (g/cm.sup.3) 3.14 3.21 3.23 3.16 3.10 3.13 3.09 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.19 0.19 0.19 0.24 0.33 0.26 0.39 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00059 TABLE 59 Example Example Example Example Example Example Example (mol %) 412 413 414 415 416 417 418 SiO.sub.2 49 47 49 47 49 47 48 Al.sub.2O.sub.3 9 9 8 8 7 8 9 B.sub.2O.sub.3 3 3 3 4 3 4 3 MgO 19 20 19 19 20 20 20 CaO 4 5 4 4 5 5 5 SrO 4 4 4 4 3 3 4 BaO 4 3 4 4 4 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 4 5 5 6 5 5 4 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 11 10 10 9 10 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.49 0.47 0.49 0.47 0.49 0.48 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.37 0.34 0.35 0.34 0.35 0.36 MgO/RO 0.54 0.54 0.53 0.51 0.54 0.54 0.56 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 98 100 98 98 98 99 100 Coefficient of thermal expansion (ppm/ C.) 5.58 5.64 5.79 5.85 5.68 5.68 5.60 Liquidus temperature TL ( C.) 1225 1225 1225 1225 1212 1220 1225 Young's modulus parameter Y 0.99 1.01 0.98 0.98 0.98 0.98 1.00 Liquidus parameter L 9.7 9.5 9.3 9.1 9.5 9.5 9.5 Thermal expansion parameter C 1.12 1.14 1.15 1.16 1.14 1.14 1.13 Glass transition point ( C.) 716 716 715 711 717 713 715 Density (g/cm.sup.3) 3.09 3.11 3.20 3.23 3.11 3.11 3.07 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.37 0.22 0.33 0.16 0.39 0.23 0.32 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00060 TABLE 60 Example Example Example Example Example Example Example (mol %) 419 420 421 422 423 424 425 SiO.sub.2 49 48 48 48 49 48 47 Al.sub.2O.sub.3 9 9 9 8 8 8 9 B.sub.2O.sub.3 3 3 3 4 3 3 4 MgO 19 20 19 20 20 20 19 CaO 4 5 5 4 4 5 5 SrO 4 3 3 4 4 4 3 BaO 3 3 3 3 4 3 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 5 6 5 4 5 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 2 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 11 11 10 10 10 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.48 0.48 0.48 0.47 0.48 0.49 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.36 0.35 0.35 0.35 0.35 0.35 MgO/RO 0.54 0.56 0.53 0.56 0.56 0.54 0.53 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 99 100 100 99 98 99 99 Coefficient of thermal expansion (ppm/ C.) 5.61 5.63 5.68 5.71 5.66 5.81 5.75 Liquidus temperature TL ( C.) 1225 1225 1220 1225 1225 1225 1225 Young's modulus parameter Y 0.99 1.00 1.00 0.99 0.99 1.00 0.98 Liquidus parameter L 9.3 9.4 9.4 9.0 9.6 9.2 9.4 Thermal expansion parameter C 1.12 1.12 1.12 1.14 1.13 1.16 1.14 Glass transition point ( C.) 716 718 717 709 714 713 715 Density (g/cm.sup.3) 3.17 3.16 3.20 3.16 3.09 3.18 3.19 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.35 0.30 0.14 0.30 0.40 0.28 0.18 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00061 TABLE 61 Example Example Example Example Example Example Example (mol %) 426 427 428 429 430 431 432 SiO.sub.2 48 47 48 49 49 48 48 Al.sub.2O.sub.3 9 9 8 8 8 9 9 B.sub.2O.sub.3 4 3 4 4 3 4 4 MgO 20 18 19 18 18 18 18 CaO 4 5 4 4 5 4 4 SrO 3 4 3 4 4 4 5 BaO 3 4 4 3 4 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 6 6 6 5 5 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 11 10 10 10 11 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.49 0.48 0.47 0.47 0.48 0.48 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.35 0.34 0.33 0.33 0.34 0.34 MgO/RO 0.57 0.49 0.53 0.51 0.50 0.51 0.51 N 11 11 $1 11 11 11 11 Young's modulus E (GPa) 99 99 98 98 98 98 98 Coefficient of thermal expansion (ppm/ C.) 5.53 5.72 5.69 5.69 5.69 5.73 5.57 Liquidus temperature TL ( C.) 1225 1225 1220 1216 1218 1225 1224 Young's modulus parameter Y 0.99 0.99 0.97 0.98 0.98 0.97 0.99 Liquidus parameter L 9.3 9.6 9.3 9.1 9.6 9.4 9.3 Thermal expansion parameter C 1.10 1.15 1.13 1.12 1.14 1.13 1.13 Glass transition point ( C.) 714 716 713 709 714 712 710 Density (g/cm.sup.3) 3.15 3.17 3.21 3.20 3.12 3.20 3.10 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.32 0.14 0.26 0.20 0.32 0.23 0.25 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00062 TABLE 62 Example Example Example Example Example Example Example (mol %) 433 434 435 436 437 438 439 SiO.sub.2 49 49 49 49 48 49 49 Al.sub.2O.sub.3 8 8 8 8 9 7 9 B.sub.2O.sub.3 3 4 4 3 3 3 3 MgO 20 18 18 19 18 19 20 CaO 4 4 5 5 5 4 4 SrO 3 3 4 3 4 5 3 BaO 4 4 3 3 4 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 6 5 6 5 6 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 10 10 10 10 11 9 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.47 0.47 0.47 0.48 0.47 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.33 0.33 0.34 0.35 0.33 0.36 MgO/RO 0.56 0.51 0.51 0.53 0.50 0.51 0.57 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 99 97 98 99 99 98 100 Coefficient of thermal expansion (ppm/ C.) 5.70 5.69 5.69 5.69 5.67 5.70 5.51 Liquidus temperature TL ( C.) 1224 1217 1218 1217 1224 1218 1224 Young's modulus parameter Y 0.98 0.97 0.98 0.99 0.99 0.99 1.00 Liquidus parameter L 9.4 9.4 9.2 9.3 9.7 9.2 9.4 Thermal expansion parameter C 1.12 1.11 1.13 1.12 1.14 1.15 1.09 Glass transition point ( C.) 717 711 709 716 716 713 718 Density (g/cm.sup.3) 3.18 3.21 3.16 3.19 3.13 3.13 3.15 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.38 0.20 0.32 0.22 0.23 0.34 0.40 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00063 TABLE 63 Example Example Example Example Example Example Example (mol %) 440 441 442 443 444 445 446 SiO.sub.2 48 49 48 47 49 48 47 Al.sub.2O.sub.3 8 8 8 8 7 9 9 B.sub.2O.sub.3 4 4 4 4 3 3 4 MgO 19 18 20 19 19 19 19 CaO 4 5 4 4 4 4 4 SrO 4 3 4 5 4 4 4 BaO 4 4 4 3 4 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 5 4 6 6 6 6 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 10 10 10 10 9 11 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.47 0.48 0.49 0.47 0.48 0.49 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.33 0.35 0.35 0.33 0.35 0.35 MgO/RO 0.53 0.51 0.56 0.51 0.51 0.53 0.53 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 98 97 98 99 98 100 99 Coefficient of thermal expansion (ppm/ C.) 5.81 5.70 5.68 5.70 5.70 5.65 5.67 Liquidus temperature TL ( C.) 1224 1220 1224 1224 1214 1224 1224 Young's modulus parameter Y 0.97 0.96 0.98 0.99 0.98 1.00 0.99 Liquidus parameter L 9.2 9.4 9.4 9.1 9.4 9.3 9.1 Thermal expansion parameter C 1.15 1.13 1.14 1.15 1.14 1.13 1.13 Glass transition point ( C.) 711 713 710 709 714 716 712 Density (g/cm.sup.3) 3.20 3.18 3.09 3.14 3.15 3.20 3.20 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.26 0.32 0.32 0.18 0.34 0.25 0.18 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00064 TABLE 64 Example Example Example Example Example Example Example (mol %) 447 448 449 450 451 452 453 SiO.sub.2 48 49 48 47 48 48 48 Al.sub.2O.sub.3 8 9 8 9 8 8 9 B.sub.2O.sub.3 4 3 4 3 3 3 3 MgO 20 18 18 19 20 19 18 CaO 4 4 5 5 5 4 4 SrO 3 4 4 3 3 4 4 BaO 4 4 4 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 5 5 6 5 6 6 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 2 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 10 11 10 11 10 10 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.47 0.48 0.49 0.48 0.48 0.48 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.34 0.33 0.36 0.35 0.35 0.35 MgO/RO 0.56 0.51 0.50 0.51 0.54 0.51 0.50 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 98 98 98 100 99 99 99 Coefficient of thermal expansion (ppm/ C.) 5.71 5.71 5.71 5.78 5.82 5.68 5.76 Liquidus temperature TL ( C.) 1224 1224 1220 1224 1224 1224 1224 Young's modulus parameter Y 0.98 0.98 0.97 0.99 0.99 0.99 0.99 Liquidus parameter L 9.3 9.5 9.5 9.5 9.4 9.5 9.4 Thermal expansion parameter C 1.13 1.13 1.15 1.15 1.15 1.14 1.14 Glass transition point ( C.) 713 716 710 719 717 715 717 Density (g/cm.sup.3) 3.18 3.20 3.12 3.23 3.19 3.15 3.23 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.30 0.31 0.24 0.16 0.28 0.26 0.21 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00065 TABLE 65 Example Example Example Example Example Example Example (mol %) 454 455 456 457 458 459 460 SiO.sub.2 48 48 49 47 49 49 49 Al.sub.2O.sub.3 8 8 9 9 8 8 8 B.sub.2O.sub.3 4 4 3 4 3 4 3 MgO 19 18 19 18 20 19 19 CaO 5 4 4 5 4 4 5 SrO 3 5 3 3 4 3 4 BaO 3 3 4 4 3 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 6 5 6 5 5 4 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 10 10 11 11 10 10 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.48 0.47 0.49 0.47 0.47 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.33 0.35 0.35 0.35 0.34 0.34 MgO/RO 0.53 0.50 0.54 0.50 0.56 0.54 0.53 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 99 98 99 99 99 98 98 Coefficient of thermal expansion (ppm/ C.) 5.71 5.78 5.61 5.72 5.69 5.72 5.71 Liquidus temperature TL ( C.) 1216 1224 1224 1224 1224 1219 1224 Young's modulus parameter Y 0.98 0.98 0.98 0.98 0.99 0.97 0.98 Liquidus parameter L 9.2 9.0 9.6 9.4 9.2 9.4 9.6 Thermal expansion parameter C 1.13 1.15 1.11 1.14 1.13 1.11 1.15 Glass transition point ( C.) 711 709 719 715 714 711 714 Density (g/cm.sup.3) 3.19 3.21 3.18 3.22 3.16 3.19 3.10 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.15 0.21 0.35 0.14 0.38 0.24 0.36 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00066 TABLE 66 Exampla Example Example Example Example Example Example (mol %) 461 462 463 464 465 466 467 SiO.sub.2 48 49 48 49 49 48 49 Al.sub.2O.sub.3 9 7 9 8 8 8 7 B.sub.2O.sub.3 3 3 4 3 3 3 3 MgO 19 20 19 18 18 19 20 CaO 5 4 4 5 4 4 4 SrO 3 5 4 4 5 4 4 BaO 4 3 4 3 3 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 5 4 6 6 6 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 9 11 10 10 10 9 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.47 0.48 0.47 0.47 0.48 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.34 0.35 0.33 0.33 0.35 0.34 MgO/RO 0.53 0.54 0.54 0.50 0.50 0.51 0.54 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 99 98 98 98 98 99 98 Coefficient of thermal expansion (ppm/ C.) 5.73 5.72 5.60 5.72 5.77 5.84 5.72 Liquidus temperature TL ( C.) 1224 1220 1224 1219 1224 1224 1216 Young's modulus parameter Y 0.99 0.99 0.98 0.99 0.99 0.98 0.98 Liquidus parameter L 9.6 9.2 9.6 9.2 9.1 9.3 9.4 Thermal expansion parameter C 1.14 1.15 1.12 1.14 1.15 1.16 1.15 Glass transition point ( C.) 719 713 712 713 713 715 714 Density (g/cm.sup.3) 3.19 3.10 3.09 3.19 3.21 3.23 3.12 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.25 0.38 0.30 0.29 0.29 0.23 0.39 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00067 TABLE 67 Example Example Example Example Example Example Example (mol %) 468 469 470 471 472 473 474 SiO.sub.2 47 49 47 48 48 48 48 Al.sub.2O.sub.3 9 8 8 8 9 8 9 B.sub.2O.sub.3 3 3 4 4 4 3 3 MgO 20 18 19 19 19 20 20 CaO 5 5 5 4 4 5 4 SrO 3 3 4 5 4 4 4 BaO 4 4 4 3 3 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 6 5 5 5 5 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 10 10 10 11 10 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.49 0.47 0.49 0.48 0.48 0.48 0.48 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.33 0.35 0.34 0.35 0.35 0.36 MgO/RO 0.54 0.50 0.51 0.53 0.54 0.54 0.56 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 100 98 98 98 99 99 100 Coefficient of thermal expansion (ppm/ C.) 5.64 5.72 5.77 5.65 5.63 5.66 5.52 Liquidus temperature TL ( C.) 1224 1220 1224 1223 1223 1223 1223 Young's modulus parameter Y 1.00 0.98 0.98 0.99 0.99 1.00 1.01 Liquidus parameter L 9.7 9.5 9.4 9.2 9.2 9.4 9.5 Thermal expansion parameter C 1.14 1.13 1.16 1.14 1.12 1.14 1.11 Glass transition point ( C.) 719 717 710 709 712 713 716 Density (g/cm.sup.3) 3.12 3.21 3.13 3.10 3.16 3.10 3.10 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.22 0.29 0.19 0.28 0.28 0.31 0.32 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00068 TABLE 68 Example Example Example Example Exampla Example Example (mol %) 475 476 477 478 479 480 481 SiO.sub.2 49 49 48 48 48 47 48 Al.sub.2O.sub.3 9 8 8 7 8 9 9 B.sub.2O.sub.3 3 3 4 3 4 4 4 MgO 18 19 18 19 18 19 18 CaO 5 5 5 4 5 4 5 SrO 3 4 4 5 3 3 3 BaO 4 3 3 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 5 6 6 6 6 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 2 2 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 10 10 9 10 11 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.47 0.48 0.48 0.48 0.49 0.48 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.34 0.33 0.34 0.33 0.35 0.34 MgO/RO 0.51 0.53 0.50 0.50 0.50 0.53 0.51 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 98 99 98 98 98 99 98 Coefficient of thermal expansion (ppm/ C.) 5.66 5.74 5.74 5.86 5.74 5.67 5.68 Liquidus temperature TL ( C.) 1223 1223 1219 1223 1220 1223 1223 Young's modulus parameter Y 0.98 0.99 0.98 0.99 0.97 0.98 0.97 Liquidus parameter L 9.6 9.2 9.1 9.2 9.3 9.4 9.5 Thermal expansion parameter C 1.12 1.14 1.15 1.18 1.14 1.12 1.13 Glass transition point ( C.) 719 713 709 714 713 715 715 Density (g/cm.sup.3) 3.19 3.17 3.19 3.17 3.21 3.22 3.18 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.31 0.34 0.22 0.24 0.22 0.18 0.23 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00069 TABLE 69 Example Example Example Example Example Example Example (mol %) 482 483 484 485 486 487 488 SiO.sub.2 48 49 47 47 47 48 47 Al.sub.2O.sub.3 9 8 9 9 8 9 9 B.sub.2O.sub.3 3 3 4 4 4 3 4 MgO 18 19 18 20 19 18 18 CaO 5 4 5 5 4 4 5 SrO 4 3 4 4 4 4 4 BaO 3 4 3 3 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 6 6 4 6 6 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 10 11 11 10 11 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.47 0.49 0.49 0.49 0.48 0.49 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.34 0.35 0.36 0.35 0.35 0.35 MgO/RO 0.50 0.53 0.50 0.56 0.51 0.50 0.50 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 99 98 99 99 98 99 98 Coefficient of thermal expansion (ppm/ C.) 5.70 5.74 5.72 5.61 5.70 5.60 5.69 Liquidus temperature TL ( C.) 1223 1218 1223 1223 1223 1223 1223 Young's modulus parameter Y 1.00 0.98 0.99 1.00 0.98 0.99 0.98 Liquidus parameter L 9.3 9.4 9.2 9.4 9.3 9.7 9.6 Thermal expansion parameter C 1.14 1.12 1.14 1.14 1.15 1.13 1.15 Glass transition point ( C.) 716 717 711 711 711 717 712 Density (g/cm.sup.3) 3.20 3.23 3.20 3.07 3.15 3.16 3.13 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.21 0.22 0.14 0.25 0.18 0.23 0.16 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00070 TABLE 70 Example Example Example Example Example Example Example (mol %) 489 490 491 492 493 494 495 SiO.sub.2 48 48 48 49 48 48 49 Al.sub.2O.sub.3 8 9 8 8 9 8 8 B.sub.2O.sub.3 4 4 4 4 3 4 3 MgO 20 18 18 19 19 19 20 CaO 5 4 5 4 5 4 5 SrO 3 3 4 5 4 3 3 BaO 3 4 4 3 3 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 4 5 4 5 6 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 10 13 10 10 11 10 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 4 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.47 0.48 0.47 0.48 0.48 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.34 0.33 0.34 0.35 0.34 0.35 MgO/RO 0.56 0.55 0.50 0.54 0.53 0.53 0.56 N 11 12 11 11 11 11 11 Young's modulus E (GPa) 99 100 97 98 100 98 99 Coefficient of thermal expansion (ppm/ C.) 5.66 5.75 5.86 5.61 5.57 5.78 5.65 Liquidus temperature TL ( C.) 1223 1214 1223 1223 1223 1219 1223 Young's modulus parameter Y 0.99 1.01 0.97 0.98 1.00 0.97 0.99 Liquidus parameter L 9.2 9.5 9.2 9.3 9.5 9.3 9.3 Thermal expansion parameter C 1.13 1.15 1.16 1.13 1.13 1.13 1.12 Glass transition point ( C.) 712 715 710 709 716 712 716 Density (g/cm.sup.3) 3.15 3.26 3.20 3.07 3.10 3.22 3.15 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.31 0.25 0.22 0.38 0.28 0.14 0.38 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00071 TABLE 71 Example Example Example Example Example Example Example (mol %) 496 497 498 499 500 501 502 SiO.sub.2 47 49 49 49 48 49 49 Al.sub.2O.sub.3 9 8 8 9 9 8 8 B.sub.2O.sub.3 3 3 4 3 3 4 4 MgO 19 20 18 18 18 18 18 CaO 5 5 5 5 5 5 4 SrO 4 4 4 4 3 3 3 BaO 3 3 3 3 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 4 5 5 6 5 4 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 10 10 11 11 10 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.49 0.47 0.47 0.47 0.48 0.47 0.46 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.35 0.33 0.34 0.35 0.33 0.33 MgO/RO 0.51 0.56 0.51 0.51 0.50 0.51 0.55 N 11 11 11 11 11 11 12 Young's modulus E (GPa) 100 99 98 99 99 97 98 Coefficient of thermal expansion (ppm/ C.) 5.62 5.61 5.76 5.66 5.71 5.77 5.77 Liquidus temperature TL ( C.) 1223 1222 1218 1222 1222 1218 1211 Young's modulus parameter Y 1.01 1.00 0.97 0.99 0.98 0.96 1.00 Liquidus parameter L 9.5 9.4 9.2 9.4 9.6 9.4 9.4 Thermal expansion parameter C 1.14 1.13 1.13 1.13 1.13 1.13 1.15 Glass transition point ( C.) 716 713 709 715 719 711 713 Density (g/cm.sup.3) 3.13 3.06 3.17 3.17 3.22 3.19 3.25 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.18 0.40 0.20 0.31 0.21 0.20 0.34 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00072 TABLE 72 Example Example Example Example Example Example Example (mol %) 503 504 505 506 507 508 509 SiO.sub.2 47 48 47 49 49 48 48 Al.sub.2O.sub.3 9 8 8 7 9 9 9 B.sub.2O.sub.3 4 3 4 3 4 4 4 MgO 20 19 19 19 18 19 18 CaO 4 5 5 5 4 4 5 SrO 4 4 4 4 5 3 4 BaO 3 3 3 4 3 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 6 6 5 4 5 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 10 10 9 11 11 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.49 0.48 0.49 0.47 0.47 0.48 0.48 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.35 0.35 0.33 0.34 0.35 0.34 MgO/RO 0.56 0.51 0.51 0.51 0.53 0.54 0.51 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 100 99 99 98 98 98 99 Coefficient of thermal expansion (ppm/ C.) 5.54 5.79 5.80 5.77 5.53 5.63 5.68 Liquidus temperature TL ( C.) 1222 1222 1222 1215 1222 1222 1222 Young's modulus parameter Y 1.00 0.99 0.99 0.98 0.98 0.98 0.98 Liquidus parameter L 9.3 9.2 9.0 9.4 9.4 9.4 9.3 Thermal expansion parameter C 1.12 1.16 1.16 1.16 1.11 1.11 1.13 Glass transition point ( C.) 711 714 710 714 710 715 711 Density (g/cm.sup.3) 3.09 3.20 3.20 3.12 3.07 3.18 3.17 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.24 0.24 0.16 0.34 0.35 0.28 0.23 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00073 TABLE 73 Example Example Example Example Example Example Example (mol %) 510 511 512 513 514 515 516 SiO.sub.2 49 49 48 48 49 47 49 Al.sub.2O.sub.3 8 9 8 9 8 8 8 B.sub.2O.sub.3 3 3 3 3 4 4 4 MgO 18 19 18 18 20 20 18 CaO 5 5 5 4 4 5 4 SrO 4 3 4 3 3 4 5 BaO 4 3 4 4 3 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 5 6 5 5 5 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 2 2 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 10 11 10 13 10 10 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 4 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.47 0.48 0.47 0.47 0.49 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.33 0.35 0.34 0.35 0.35 0.35 0.33 MgO/RO 0.50 0.54 0.49 0.53 0.57 0.54 0.51 N 11 11 11 12 11 11 11 Young's modulus E (GPa) 98 99 98 101 98 99 97 Coefficient of thermal expansion (ppm/ C.) 5.85 5.56 5.89 5.78 5.54 5.67 5.74 Liquidus temperature TL ( C.) 1222 1222 1222 1219 1222 1222 1222 Young's modulus parameter Y 0.97 0.99 0.98 1.02 0.98 0.99 0.98 Liquidus parameter L 9.4 9.5 9.3 9.5 9.2 9.2 9.0 Thermal expansion parameter C 1.16 1.11 1.17 1.16 1.10 1.15 1.14 Glass transition point ( C.) 714 718 714 719 712 709 709 Density (g/cm.sup.3) 3.20 3.15 3.24 3.30 3.14 3.10 3.17 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.29 0.36 0.19 0.23 0.40 0.23 0.31 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00074 TABLE 74 Example Example Example Example Example Example Example (mol %) 517 518 519 520 521 522 523 SiO.sub.2 47 49 48 49 48 49 49 Al.sub.2O.sub.3 9 8 8 8 9 8 8 B.sub.2O.sub.3 4 3 4 3 3 3 3 MgO 18 19 19 18 20 18 18 CaO 4 5 5 5 5 5 4 SrO 4 3 4 4 3 3 5 BaO 4 4 4 3 4 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 5 4 6 4 6 6 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 10 10 10 11 10 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.49 0.47 0.48 0.47 0.48 0.47 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.34 0.34 0.33 0.36 0.33 0.33 MgO/RO 0.50 0.53 0.53 0.50 0.56 0.50 0.50 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 99 98 98 98 99 98 98 Coefficient of thermal expansion (ppm/ C.) 5.62 5.75 5.73 5.79 5.60 5.80 5.61 Liquidus temperature TL ( C.) 1222 1222 1222 1218 1222 1217 1222 Young's modulus parameter Y 0.98 0.98 0.97 0.99 0.99 0.98 0.99 Liquidus parameter L 9.5 9.5 9.5 9.2 9.8 9.5 9.3 Thermal expansion parameter C 1.13 1.14 1.15 1.14 1.12 1.13 1.13 Glass transition point ( C.) 712 717 710 714 719 716 713 Density (g/cm.sup.3) 3.15 3.19 3.09 3.21 3.09 3.23 3.13 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.16 0.34 0.28 0.18 0.32 0.18 0.31 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00075 TABLE 75 Exampla Example Example Example Example Example Example (mol %) 524 525 526 527 528 529 530 SiO.sub.2 48 49 48 49 48 49 48 Al.sub.2O.sub.3 8 7 8 7 9 9 8 B.sub.2O.sub.3 4 3 4 3 3 3 4 MgO 19 18 18 20 19 19 19 CaO 4 4 4 5 4 5 5 SrO 4 5 5 4 3 4 4 BaO 4 4 3 4 4 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 6 6 4 6 4 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 10 9 10 9 11 11 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.47 0.48 0.47 0.48 0.47 0.48 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.32 0.33 0.34 0.35 0.35 0.34 MgO/RO 0.53 0.49 0.50 0.54 0.53 0.54 0.53 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 98 97 98 98 99 99 98 Coefficient of thermal expansion (ppm/ C.) 5.66 5.80 5.63 5.80 5.66 5.53 5.76 Liquidus temperature TL ( C.) 1222 1218 1222 1219 1222 1222 1222 Young's modulus parameter Y 0.98 0.98 0.99 0.98 0.99 1.00 0.98 Liquidus parameter L 9.4 9.3 9.2 9.4 9.5 9.6 9.1 Thermal expansion parameter C 1.13 1.16 1.14 1.16 1.12 1.12 1.15 Glass transition point ( C.) 711 714 709 714 719 715 709 Density (g/cm.sup.3) 3.12 3.16 3.13 3.10 3.22 3.06 3.17 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.28 0.30 0.24 0.39 0.25 0.38 0.26 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00076 TABLE 76 Example Example Example Example Example Example Example (mol %) 531 532 533 534 535 536 537 SiO.sub.2 49 49 49 48 48 48 49 Al.sub.2O.sub.3 7 9 7 8 9 8 8 B.sub.2O.sub.3 3 3 3 4 4 4 3 MgO 19 18 19 18 18 18 19 CaO 5 5 5 4 4 5 4 SrO 4 4 3 4 3 4 4 BaO 3 4 4 4 4 3 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 4 6 6 6 6 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 9 11 9 10 11 10 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.47 0.47 0.48 0.48 0.48 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.33 0.34 0.33 0.33 0.34 0.33 0.34 MgO/RO 0.51 0.51 0.51 0.50 0.51 0.50 0.53 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 98 98 98 98 98 98 98 Coefficient of thermal expansion (ppm/ C.) 5.80 5.63 5.81 5.79 5.61 5.81 5.64 Liquidus temperature TL ( C.) 1216 1222 1215 1222 1222 1219 1222 Young's modulus parameter Y 0.99 0.98 0.98 0.97 0.98 0.98 0.98 Liquidus parameter L 9.1 9.8 9.3 9.2 9.4 9.1 9.6 Thermal expansion parameter C 1.16 1.13 1.15 1.15 1.11 1.15 1.13 Glass transition point ( C.) 713 716 717 711 715 709 715 Density (g/cm.sup.3) 3.19 3.10 3.21 3.22 3.21 3.21 3.12 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.32 0.33 0.32 0.21 0.23 0.10 0.36 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00077 TABLE 77 Example Example Example Example Example Example Example (mol %) 538 539 540 541 542 543 544 SiO.sub.2 48 48 49 48 49 48 49 Al.sub.2O.sub.3 9 8 8 8 8 7 8 B.sub.2O.sub.3 4 4 4 4 3 3 3 MgO 18 18 18 18 19 19 19 CaO 5 5 5 4 4 5 5 SrO 4 3 3 3 4 4 3 BaO 4 4 4 4 3 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 4 6 5 6 6 6 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 10 12 12 10 9 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 4 4 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.48 0.47 0.47 0.47 0.48 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.33 0.33 0.33 0.34 0.34 0.34 MgO/RO 0.51 0.50 0.51 0.53 0.53 0.50 0.53 N 11 11 10 12 11 11 11 Young's modulus E (GPa) 98 98 98 100 99 98 98 Coefficient of thermal expansion (ppm/ C.) 5.65 5.81 5.81 5.81 5.67 5.82 5.82 Liquidus temperature TL ( C.) 1222 1219 1206 1215 1222 1217 1220 Young's modulus parameter Y 0.98 0.97 0.98 1.00 0.99 0.98 0.98 Liquidus parameter L 9.6 9.3 9.1 9.3 9.2 9.4 9.5 Thermal expansion parameter C 1.13 1.14 1.16 1.16 1.13 1.17 1.14 Glass transition point ( C.) 712 711 710 713 714 714 716 Density (g/cm.sup.3) 3.10 3.23 3.27 3.29 3.19 3.16 3.20 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.26 0.10 0.04 0.24 0.34 0.25 0.22 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00078 TABLE 78 Example Example Example Example Example Example Example (mol %) 545 546 547 548 549 550 551 SiO.sub.2 47 48 49 47 47 47 48 Al.sub.2O.sub.3 9 8 8 9 8 9 8 B.sub.2O.sub.3 3 4 3 4 4 3 4 MgO 19 20 19 19 19 18 20 CaO 4 5 4 4 5 4 4 SrO 3 4 3 3 3 3 4 BaO 4 3 4 4 4 4 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 4 4 4 6 6 5 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 2 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 10 12 13 10 13 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 2 4 4 2 4 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.48 0.46 0.48 0.49 0.48 0.48 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.35 0.34 0.35 0.35 0.35 0.35 MgO/RO 0.54 0.56 0.56 0.56 0.51 0.51 0.56 N 12 11 12 12 11 12 11 Young's modulus E (GPa) 102 99 100 101 99 102 99 Coefficient of thermal expansion (ppm/ C.) 5.85 5.63 5.82 5.82 5.81 5.83 5.55 Liquidus temperature TL ( C.) 1221 1221 1218 1217 1221 1220 1221 Young's modulus parameter Y 1.03 0.99 1.01 1.01 0.98 1.02 0.99 Liquidus parameter L 9.5 9.3 9.4 9.4 9.3 9.5 9.3 Thermal expansion parameter C 1.17 1.14 1.16 1.17 1.15 1.17 1.12 Glass transition point ( C.) 719 709 717 715 713 719 709 Density (g/cm.sup.3) 3.31 3.06 3.26 3.27 3.22 3.33 3.08 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.17 0.33 0.36 0.20 0.16 0.13 0.33 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00079 TABLE 79 Example Example Example Example Example Example Example (mol %) 552 553 554 555 556 557 558 SiO.sub.2 49 49 48 49 48 49 48 Al.sub.2O.sub.3 7 9 8 7 8 9 8 B.sub.2O.sub.3 3 3 3 3 3 4 4 MgO 20 18 20 20 18 18 19 CaO 5 4 5 5 5 4 4 SrO 4 3 3 3 4 3 3 BaO 3 4 4 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 6 5 5 6 5 4 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 2 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 9 11 10 9 10 11 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.47 0.48 0.47 0.48 0.47 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.34 0.35 0.34 0.34 0.34 0.34 MgO/RO 0.54 0.51 0.54 0.54 0.49 0.53 0.56 N 11 11 11 11 11 11 12 Young's modulus E (GPa) 98 99 99 98 98 98 100 Coefficient of thermal expansion (ppm/ C.) 5.83 5.59 5.66 5.83 5.73 5.56 5.84 Liquidus temperature TL ( C.) 1218 1221 1221 1219 1221 1221 1214 Young's modulus parameter Y 0.99 0.98 0.99 0.98 0.99 0.97 1.01 Liquidus parameter L 9.1 9.6 9.6 9.3 9.5 9.5 9.3 Thermal expansion parameter C 1.16 1.11 1.14 1.15 1.15 1.10 1.17 Glass transition point ( C.) 713 719 717 717 714 715 713 Density (g/cm.sup.3) 3.17 3.21 3.12 3.19 3.16 3.17 3.26 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.36 0.31 0.31 0.36 0.22 0.33 0.28 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00080 TABLE 80 Example Example Example Example Example Example Example (mol %) 559 560 561 562 563 564 565 SiO.sub.2 48 48 48 49 48 48 49 Al.sub.2O.sub.3 9 8 7 8 9 8 8 B.sub.2O.sub.3 3 3 3 3 4 3 4 MgO 20 18 20 18 18 19 20 CaO 4 4 5 4 4 5 4 SrO 3 3 4 4 4 4 4 BaO 4 4 4 4 4 3 3 Li.sub.2O Na.sub.2O K.sub.2O 5 6 5 6 5 6 4 ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 12 9 10 11 10 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 4 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.47 0.48 0.47 0.48 0.48 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.34 0.35 0.33 0.34 0.35 0.35 MgO/RO 0.56 0.51 0.53 0.50 0.51 0.51 0.57 N 11 12 11 11 11 11 11 Young's modulus E (GPa) 100 101 98 98 98 99 98 Coefficient of thermal expansion (ppm/ C.) 5.53 5.84 5.84 5.84 5.57 5.63 5.51 Liquidus temperature TL ( C.) 1221 1218 1219 1219 1221 1221 1221 Young's modulus parameter Y 0.99 1.02 0.99 0.98 0.98 1.00 0.99 Liquidus parameter L 9.7 9.4 9.4 9.3 9.6 9.4 9.3 Thermal expansion parameter C 1.11 1.17 1.17 1.14 1.12 1.14 1.11 Glass transition point ( C.) 719 718 714 715 712 714 708 Density (g/cm.sup.3) 3.11 3.33 3.13 3.24 3.12 3.12 3.05 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.32 0.21 0.29 0.17 0.26 0.26 0.43 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00081 TABLE 81 Example Example Example Example Example Example Example (mol %) 566 567 568 569 570 571 572 SiO.sub.2 48 48 49 47 49 49 48 Al.sub.2O.sub.3 9 9 7 9 7 7 9 B.sub.2O.sub.3 3 4 3 4 3 3 3 MgO 19 18 19 19 19 19 18 CaO 5 4 4 5 4 4 5 SrO 3 4 5 3 4 5 3 BaO 3 3 3 3 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 6 6 6 6 6 5 4 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 2 2 2 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 11 9 11 9 9 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.48 0.47 0.49 0.47 0.47 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.34 0.33 0.35 0.33 0.33 0.35 MgO/RO 0.53 0.51 0.51 0.53 0.51 0.51 0.53 N 11 11 11 11 11 11 12 Young's modulus E (GPa) 100 99 98 100 98 97 101 Coefficient of thermal expansion (ppm/ C.) 5.61 5.60 5.85 5.62 5.85 5.82 5.86 Liquidus temperature TL ( C.) 1221 1221 1219 1221 1218 1221 1220 Young's modulus parameter Y 1.00 0.99 0.99 0.99 0.98 0.98 1.02 Liquidus parameter L 9.4 9.2 8.9 9.3 9.2 9.3 9.6 Thermal expansion parameter C 1.12 1.12 1.17 1.12 1.16 1.17 1.17 Glass transition point ( C.) 718 712 713 714 714 714 719 Density (g/cm.sup.3) 3.19 3.19 3.21 3.19 3.22 3.14 3.28 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.26 0.23 0.32 0.18 0.32 0.34 0.23 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00082 TABLE 82 Example Example Example Example Example Example Example (mol %) 573 574 576 576 577 578 578 SiO.sub.2 48 49 48 49 48 49 49 Al.sub.2O.sub.3 8 8 8 8 8 7 9 B.sub.2O.sub.3 4 3 3 4 4 3 3 MgO 19 18 19 18 19 19 18 CaO 5 4 5 4 4 5 4 SrO 3 4 3 4 4 4 4 BaO 4 4 4 4 4 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 6 6 5 4 6 6 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 Gd.sub.2O.sub.3 2 2 La.sub.2O.sub.3 2 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 10 10 10 10 10 9 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.47 0.48 0.47 0.47 0.47 0.47 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.33 0.35 0.33 0.34 0.33 0.34 MgO/RO 0.53 0.50 0.51 0.51 0.54 0.51 0.51 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 98 98 99 97 97 98 99 Coefficient of thermal expansion (ppm/ C.) 5.76 5.77 5.86 5.74 5.61 5.88 5.59 Liquidus temperature TL ( C.) 1221 1221 1219 1221 1221 1215 1221 Young's modulus parameter Y 0.97 0.98 0.98 0.97 0.97 0.99 0.99 Liquidus parameter L 9.3 9.3 9.4 9.3 9.5 9.1 9.3 Thermal expansion parameter C 1.14 1.14 1.15 1.14 1.12 1.16 1.11 Glass transition point ( C.) 713 715 717 710 710 714 716 Density (g/cm.sup.3) 3.18 3.22 3.24 3.19 3.08 3.21 3.19 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.26 0.29 0.12 0.31 0.38 0.20 0.31 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00083 TABLE 83 Example Example Example Example Example Example Example (mol %) 580 581 582 583 584 585 586 SiO.sub.2 49 49 49 48 49 49 47 Al.sub.2O.sub.3 7 7 8 8 8 8 8 B.sub.2O.sub.3 3 3 3 4 4 3 4 MgO 20 19 19 19 19 20 18 CaO 4 5 4 4 4 4 5 SrO 4 3 3 4 3 4 4 BaO 4 4 4 3 4 3 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 6 6 6 5 5 6 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 2 2 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 9 9 10 10 10 10 10 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.47 0.47 0.48 0.47 0.47 0.49 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.33 0.34 0.34 0.34 0.35 0.34 MgO/RO 0.54 0.51 0.53 0.53 0.54 0.56 0.49 N 11 11 11 11 11 11 11 Young's modulus E (GPa) 98 98 98 99 98 99 98 Coefficient of thermal expansion (ppm/ C.) 5.88 5.88 5.67 5.69 5.65 5.54 5.75 Liquidus temperature TL ( C.) 1220 1213 1221 1221 1220 1220 1220 Young's modulus parameter Y 0.98 0.97 0.98 0.99 0.97 1.00 0.98 Liquidus parameter L 9.2 9.3 9.4 9.0 9.4 9.4 9.4 Thermal expansion parameter C 1.16 1.15 1.12 1.13 1.11 1.12 1.16 Glass transition point ( C.) 714 716 717 710 713 714 710 Density (g/cm.sup.3) 3.20 3.23 3.21 3.19 3.17 3.09 3.16 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.36 0.20 0.34 0.26 0.36 0.40 0.14 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00084 TABLE 84 Example Example Example Example Example Example Example (mol %) 587 588 589 590 591 592 593 SiO.sub.2 48 49 49 48 48 49 49 Al.sub.2O.sub.3 9 8 7 8 12 11 12 B.sub.2O.sub.3 4 4 3 3 6 6 6 MgO 19 19 20 19 17 17 17 CaO 5 4 5 5 2 2 3 SrO 3 4 4 3 5 5 5 BaO 3 3 3 4 2 2 2 Li.sub.2O Na.sub.2O K.sub.2O ZnO 5 5 5 6 P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 Gd.sub.2O.sub.3 2 2 4 4 La.sub.2O.sub.3 2 2 2 4 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11 10 9 10 20 19 18 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 2 2 2 2 8 8 6 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.48 0.47 0.47 0.48 0.44 0.43 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.34 0.34 0.35 0.35 0.34 0.35 MgO/RO 0.54 0.54 0.54 0.51 0.65 0.65 0.63 N 11 11 11 11 10 10 9 Young's modulus E (GPa) 99 98 98 99 103 102 100 Coefficient of thermal expansion (ppm/ C.) 5.58 5.64 5.90 5.79 5.99 6.08 5.79 Liquidus temperature TL ( C.) 1220 1220 1217 1220 1220 1215 1212 Young's modulus parameter Y 0.99 0.98 0.99 0.98 1.05 1.05 1.02 Liquidus parameter L 9.3 9.1 9.1 9.4 8.5 8.4 8.8 Thermal expansion parameter C 1.11 1.12 1.16 1.15 1.18 1.18 1.13 Glass transition point ( C.) 714 709 714 717 702 703 702 Density (g/cm.sup.3) 3.15 3.15 3.18 3.22 3.47 3.48 3.30 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.28 0.36 0.25 0.24 0.12 0.16 0.14 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00085 TABLE 85 Example Example Example Example Example Example Example (mol %) 594 595 598 597 598 599 600 SiO.sub.2 49 49 48 49 47 49 49 Al.sub.2O.sub.3 11 11 12 12 11 10 12 B.sub.2O.sub.3 6 6 6 6 6 6 6 MgO 17 17 17 17 17 17 17 CaO 2 2 3 3 3 3 4 SrO 5 5 5 5 7 5 5 BaO 2 2 2 2 3 2 2 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 2 2 2 Gd.sub.2O.sub.3 4 2 2 La.sub.2O.sub.3 4 2 2 4 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 17 17 18 16 15 16 16 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 6 6 6 4 4 6 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.43 0.43 0.45 0.44 0.47 0.43 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.34 0.35 0.35 0.35 0.33 0.35 MgO/RO 0.65 0.65 0.63 0.63 0.57 0.63 0.61 N 11 11 11 11 11 11 10 Young's modulus E (GPa) 102 102 102 100 99 101 98 Coefficient of thermal expansion (ppm/ C.) 5.66 5.80 5.80 5.37 5.96 5.80 5.41 Liquidus temperature TL ( C.) 1220 1222 1216 1215 1221 1210 1221 Young's modulus parameter Y 1.03 1.03 1.04 1.01 1.00 1.03 0.99 Liquidus parameter L 8.9 8.9 8.8 9.4 9.1 8.8 9.3 Thermal expansion parameter C 1.13 1.13 1.15 1.08 1.18 1.16 1.09 Glass transition point ( C.) 705 705 703 704 700 704 701 Density (g/cm.sup.3) 3.27 3.31 3.30 3.09 3.19 3.28 3.08 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.38 0.14 0.07 0.40 0.06 0.36 0.22 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00086 TABLE 86 Example Example Example Example Example Example Example (mol %) 601 602 603 604 605 606 607 SiO.sub.2 47 47 49 47 49 47 49 Al.sub.2O.sub.3 12 11 11 12 12 12 12 B.sub.2O.sub.3 6 6 6 6 6 6 6 MgO 17 17 17 17 17 17 17 CaO 2 4 3 3 2 3 3 SrO 5 7 6 6 6 7 6 BaO 3 3 2 3 3 3 2 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 2 2 2 Gd.sub.2O.sub.3 2 2 2 La.sub.2O.sub.3 4 4 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 18 15 17 16 16 16 16 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 6 4 6 4 4 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.47 0.44 0.47 0.45 0.47 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.35 0.34 0.35 0.35 0.35 0.35 MgO/RO 0.63 0.55 0.61 0.59 0.61 0.57 0.61 N 11 10 9 11 10 10 10 Young's modulus E (GPa) 102 98 100 100 98 98 99 Coefficient of thermal expansion (ppm/ C.) 5.82 5.99 5.83 5.78 5.50 5.86 5.50 Liquidus temperature TL ( C.) 1223 1222 1204 1218 1220 1219 1214 Young's modulus parameter Y 1.03 0.98 1.02 1.00 0.98 0.99 1.01 Liquidus parameter L 9.1 9.0 8.6 9.3 9.3 9.1 9.0 Thermal expansion parameter C 1.16 1.19 1.17 1.15 1.10 1.16 1.11 Glass transition point ( C.) 699 697 701 700 698 700 703 Density (g/cm.sup.3) 3.32 3.18 3.28 3.17 3.12 3.17 3.11 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.19 0.12 0.08 0.08 0.21 0.11 0.28 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00087 TABLE 87 Example Example Example Example Example Example Example (mol %) 608 609 610 611 612 613 614 SiO.sub.2 47 47 47 48 48 48 48 Al.sub.2O.sub.3 12 12 12 10 11 10 11 B.sub.2O.sub.3 6 6 6 6 6 6 6 MgO 17 17 17 17 17 17 17 CaO 3 4 4 3 2 4 3 SrO 7 6 7 7 6 7 5 BaO 3 3 3 3 3 3 2 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 2 2 4 Gd.sub.2O.sub.3 2 2 2 2 4 2 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 16 16 16 14 17 14 19 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 4 4 4 6 4 8 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.47 0.47 0.48 0.45 0.45 0.46 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.35 0.35 0.33 0.34 0.33 0.34 MgO/RO 0.57 0.57 0.55 0.57 0.61 0.55 0.63 N 10 10 9 11 10 10 10 Young's modulus E (GPa) 99 96 98 98 100 97 102 Coefficient of thermal expansion (ppm/ C.) 5.91 5.81 5.94 5.98 6.05 6.01 5.97 Liquidus temperature TL ( C.) 1223 1222 1222 1223 1223 1223 1225 Young's modulus parameter Y 1.00 0.99 0.99 0.99 1.01 0.98 1.05 Liquidus parameter L 9.0 9.2 8.9 9.0 8.8 8.9 8.6 Thermal expansion parameter C 1.17 1.15 1.18 1.18 1.18 1.19 1.20 Glass transition point ( C.) 699 697 693 700 700 696 703 Density (g/cm.sup.3) 3.19 3.16 3.18 3.18 3.35 3.17 3.40 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 24 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.04 0.10 0.22 0.14 0.14 0.04 0.11 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00088 TABLE 88 Example Example Example Example Example Example Example (mol %) 615 616 617 618 619 620 621 SiO.sub.2 48 48 48 48 48 48 48 Al.sub.2O.sub.3 11 11 11 11 11 11 11 B.sub.2O.sub.3 6 6 6 6 6 6 6 MgO 17 17 17 17 17 17 17 CaO 3 3 3 3 3 3 4 SrO 6 6 6 7 7 7 6 BaO 3 3 3 2 3 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 4 4 2 2 2 2 2 Gd.sub.2O.sub.3 2 2 2 2 2 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 17 17 15 15 15 15 15 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 6 6 4 4 4 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.45 0.45 0.46 0.46 0.46 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.34 0.34 0.34 0.34 0.34 0.34 MgO/RO 0.59 0.59 0.59 0.59 0.57 0.57 0.57 N 9 9 11 11 10 10 10 Young's modulus E (GPa) 99 99 99 99 97 98 97 Coefficient of thermal expansion (ppm/ C.) 5.84 5.91 5.80 5.79 5.88 5.93 5.83 Liquidus temperature TL ( C.) 1223 1223 1215 1224 1217 1219 1220 Young's modulus parameter Y 1.01 1.01 1.00 1.01 0.98 1.00 0.98 Liquidus parameter L 8.9 8.9 9.2 9.0 9.0 8.9 9.1 Thermal expansion parameter C 1.18 1.18 1.15 1.15 1.16 1.17 1.16 Glass transition point ( C.) 697 698 700 704 700 699 697 Density (g/cm.sup.3) 3.24 3.26 3.16 3.15 3.16 3.18 3.15 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.01 0.11 0.16 0.16 0.02 0.05 0.02 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00089 TABLE 89 Example Example Example Example Example Example Example (mol %) 622 623 624 625 626 627 628 SiO.sub.2 48 49 48 48 48 48 48 Al.sub.2O.sub.3 11 11 11 12 12 12 12 B.sub.2O.sub.3 6 6 6 6 6 6 6 MgO 17 17 17 17 17 17 17 CaO 4 2 4 3 3 3 3 SrO 6 6 7 5 6 6 6 BaO 3 3 3 3 2 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 2 2 2 Gd.sub.2O.sub.3 2 2 2 2 2 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 15 15 15 18 16 16 16 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 4 4 4 4 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.44 0.47 0.45 0.45 0.46 0.46 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.34 0.34 0.35 0.35 0.35 0.35 MgO/RO 0.57 0.61 0.55 0.81 0.81 :0.59 0.53 N 10 11 11 11 10 10 Young's modulus E (GPa) 98 99 97 100 100 98 99 Coefficient of thermal expansion (ppm/ C.) 5.88 5.61 5.96 6.81 5.61 5.69 5.74 Liquidus temperature TL ( C.) 1223 1218 1219 1219 1221 1216 1217 Young's modulus parameter Y 0.99 0,99 0.98 1.00 1.01 0.96 1.00 Liquidus parameter L 9.0 9.2 8.8 9.4 9.2 9.3 9.1 Thermal expansion parameter C 1.16 1,12 1.18 1.11 1.12 1.13 1.13 Glass transition point ( C.) 695 699 694 700 704 700 698 Density (g/cm.sup.3) 3.17 3.14 3.17 3.15 3.13 3.15 3.17 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.06 0.38 0.13 0,18 0.18 0.00 0.06 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00090 TABLE 90 Example Example Example Example Example Example Example (mol %) 629 630 631 632 633 634 635 SiO.sub.2 48 48 48 48 49 49 49 Al.sub.2O.sub.3 12 12 12 12 10 10 10 B.sub.2O.sub.3 6 6 6 6 6 6 6 MgO 17 17 17 17 17 17 17 CaO 3 3 4 4 3 3 3 SrO 7 7 5 6 5 5 5 BaO 2 3 3 3 2 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 4 4 4 Gd.sub.2O.sub.3 2 2 2 2 2 2 La.sub.2O.sub.3 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 16 16 16 18 18 16 16 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 4 4 4 8 6 6 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.47 0.46 0.47 0.43 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.35 0.35 0.35 0.33 0.33 0.33 MgO/RO 0.59 0.57 0.59 0.57 0,63 0.61 0.61 N 10 9 10 9 10 10 10 Young's modulus E (GPa) 98 97 98 97 101 99 99 Coefficient of thermal expansion (ppm/ C.) 5.69 5.83 5.65 5.78 5.98 5.72 5.80 Liquidus temperature TL ( C.) 1223 1217 1224 1220 1221 1224 1224 Young's modulus parameter Y 1.00 0.98 0.98 0.98 1.05 1.01 1.01 Liquidus parameter L 9.0 8.9 9.4 9.1 8.5 9.1 9.1 Thermal expansion parameter C 1.13 1.15 1.12 1.14 1.20 1.18 1.16 Glass transition point ( C.) 703 698 697 693 702 698 699 Density (g/cm.sup.3) 3.13 3.17 3.14 3.15 3.39 3.22 3.23 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.00 0.12 0.00 0.11 0.03 0.20 0.09 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00091 TABLE 91 Example Example Example Example Example Example Example (mol %) 636 637 638 639 640 641 642 SiO.sub.2 49 49 49 49 49 48 49 Al.sub.2O.sub.3 10 10 10 10 10 12 10 B.sub.2O.sub.3 6 6 6 6 6 6 6 MgO 17 17 17 17 17 17 17 CaO 3 3 3 3 3 4 3 SrO 6 6 6 7 7 7 7 BaO 3 3 3 2 3 2 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 4 4 2 2 2 2 2 Gd.sub.2O.sub.3 2 2 2 2 2 La.sub.2O.sub.3 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 16 16 14 14 14 16 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 6 6 4 4 4 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 0.45 0.47 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.33 0.33 0.33 0.33 0.33 0.35 0.33 MgO/RO 0.59 0.59 0.59 0.59 0.57 0.57 0.57 N 9 9 11 11 10 9 10 Young's modulus E (GPa) 99 98 98 98 96 98 97 Coefficient of thermal expansion (ppm/ C.) 5.86 5.93 5.81 5.81 5.89 5.70 5.94 Liquidus temperature TL ( C.) 1219 1219 1212 1221 1213 1223 1217 Young's modulus parameter Y 1.01 1.01 0.99 1.00 0.97 0.99 0.99 Liquidus parameter L 8.8 8.8 9.1 8.9 8.9 8.8 8.8 Thermal expansion parameter C 1.18 1.18 1.15 1.15 1.16 1.15 1.17 Glass transition point ( C.) 696 698 700 703 699 695 699 Density (g/cm.sup.3) 3.23 3.25 3.15 3.14 3.15 3.12 3.17 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 24 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.09 0.03 0.24 0.24 0.06 0.00 0.13 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00092 TABLE 92 Example Example Example Example Example Example Example (mol %) 643 644 645 646 647 648 649 SiO.sub.2 49 49 49 49 49 49 49 Al.sub.2O.sub.3 10 10 10 10 10 10 10 B.sub.2O.sub.3 6 6 6 6 6 6 6 MgO 17 17 17 17 17 17 17 CaO 4 4 4 4 4 4 4 SrO 5 5 5 6 6 6 6 BaO 3 3 3 2 2 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 TiO.sub.2 1 1 Y.sub.2O.sub.3 4 4 2 4 4 2 2 Gd.sub.2O.sub.3 2 2 2 2 2 La.sub.2O.sub.3 2 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 16 16 14 16 16 14 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 6 6 4 6 6 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 0.44 0.45 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.33 0.33 0.33 0.33 0.33 0.33 0.33 MgO/RO 0.59 0.59 0.59 0.59 0,59 0.57 0.57 N 9 11 9 9 10 10 Young's modulus E (GPa) 99 99 98 99 99 97 98 Coefficient of thermal expansion (ppm/ C.) 5.81 5.88 5.76 5.81 5.88 5.84 5.90 Liquidus temperature TL ( C.) 1220 1220 1223 1223 1223 1216 1221 Young's modulus parameter Y 1.00 1.00 0.99 1.02 1.02 0.97 0.99 Liquidus parameter L 8.9 8.9 9.2 8.7 8.7 9.0 8.9 Thermal expansion parameter C 1.17 1.17 1.14 1.18 1.18 1.16 1.16 Glass transition point ( C.) 690 693 697 698 697 696 694 Density (g/cm.sup.3) 3.22 3.24 3.14 3.20 3.22 3.14 3.16 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.09 0.02 0.25 0.09 0.02 0.06 0.13 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00093 TABLE 93 Example Example Example Example Example Example Example (mol %) 650 651 652 653 654 655 656 SiO.sub.2 49 49 49 49 49 49 49 Al.sub.2O.sub.3 10 10 10 11 11 11 11 B.sub.2O.sub.3 6 6 6 6 6 6 6 MgO 17 17 17 17 17 17 17 CaO 4 4 4 2 2 3 3 SrO 7 7 7 6 7 5 5 BaO 2 3 3 3 3 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 TiO.sub.2 1 Y.sub.2O.sub.3 2 2 4 2 2 4 4 Gd.sub.2O.sub.3 2 2 2 2 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14 14 14 15 15 17 17 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 4 4 4 4 6 6 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.46 0.46 0.44 0.45 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.33 0.33 0.33 0.34 0.34 0.34 0.34 MgO/RO 0.57 0.55 0.55 0.61 0.59 0.61 0.61 N 10 9 8 11 10 9 9 Young's modulus E (GPa) 97 96 96 99 98 99 99 Coefficient of thermal expansion (ppm/ C.) 5.84 5.98 5.75 5.68 5.81 5.67 5.75 Liquidus temperature TL ( C.) 1222 1216 1225 1221 1224 1219 1219 Young's modulus parameter Y 0.98 0.97 0.98 0.99 0.99 1.01 1.01 Liquidus parameter L 8.8 8.7 8.9 9.2 8.9 9.0 9.0 Thermal expansion parameter C 1.16 1.18 1.17 1.12 1.14 1.15 1.15 Glass transition point ( C.) 700 692 689 700 699 696 698 Density (g/cm.sup.3) 3.12 3.16 3.07 3.15 3.17 3.22 3.23 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.06 0.05 0.09 0.26 0.14 0.11 0.01 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00094 TABLE 94 Example Example Example Example Exampla Example Example (mol %) 657 658 659 660 661 662 663 SiO.sub.2 49 49 49 49 49 49 49 Al.sub.2O.sub.3 11 11 11 11 11 11 11 B.sub.2O.sub.3 6 6 6 6 6 6 6 MgO 17 17 17 17 17 17 17 CaO 3 3 3 3 3 3 3 SrO 5 6 6 6 6 6 6 BaO 3 2 2 2 3 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 4 4 2 2 4 2 Gd.sub.2O.sub.3 2 2 2 2 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 15 17 17 15 15 15 15 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 6 6 4 4 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.44 0.44 0.44 0.45 0.45 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.34 0.34 0.34 0.34 0.34 0.34 MgO/RO 0.61 0.61 0.61 0.61 0.59 0.59 0.59 N 11 9 9 11 10 9 10 Young's modulus E (GPa) 99 100 100 99 97 97 98 Coefficient of thermal expansion (ppm/ C.) 5.63 5.67 5.74 5.63 5.71 5.48 5.76 Liquidus temperature TL ( C.) 1210 1222 1221 1213 1208 1225 1208 Young's modulus parameter Y 0.99 1.02 1.02 1.00 0.98 0.98 0.99 Liquidus parameter L 9.4 8.8 8.8 9.1 9.2 9.4 9.0 Thermal expansion parameter C 1.11 1.15 1.15 1.12 1.13 1.11 1.14 Glass transition point ( C.) 700 701 702 704 699 698 699 Density (g/cm.sup.3) 3.14 3.20 3.22 3.12 3.14 3.05 3.16 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.26 0.11 0.01 0.26 0.08 0.22 0.15 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00095 TABLE 95 Example Example Example Example Example Example Example (mol %) 664 665 666 667 668 669 670 SiO.sub.2 49 49 49 49 49 49 49 Al.sub.2O.sub.3 11 11 11 11 11 11 11 B.sub.2O.sub.3 6 6 6 6 6 6 6 MgO 17 17 17 17 17 17 17 CaO 3 3 3 3 3 4 4 SrO 7 7 7 7 7 5 5 BaO 2 2 3 3 3 2 2 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 TiO.sub.2 1 1 Y.sub.2O.sub.3 2 2 2 4 2 4 4 Gd.sub.2O.sub.3 2 2 2 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 15 15 15 15 13 17 17 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 4 4 4 2 6 6 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.45 0.45 0.46 0.46 0.46 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.34 0.34 0.34 0.34 0.34 0.34 MgO/RO 0.59 0.59 0.57 0.57 0.57 0.61 0.61 N 10 10 9 8 10 9 9 Young's modulus E (GPa) 97 98 96 97 96 100 100 Coefficient of thermal expansion (ppm/ C.) 5.71 5.76 5.84 5.61 5.50 5.62 5.70 Liquidus temperature TL ( C.) 1215 1218 1210 1225 1217 1224 1224 Young's modulus parameter Y 0.99 1.00 0.98 0.98 0.96 1.02 1.02 Liquidus parameter L 8.9 8.8 8.8 9.1 9.4 8.9 8.9 Thermal expansion parameter C 1.14 1.14 1.15 1.14 1.10 1.14 1.14 Glass transition point ( C.) 703 703 698 696 698 696 698 Density (g/cm.sup.3) 3.12 3.14 3.16 3.06 2.97 3.19 3.20 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.08 0.15 0.04 0.11 0.38 0.11 0.01 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) 41100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00096 TABLE 96 Example Example Example Example Example Example Example (mol %) 671 672 673 674 675 676 677 SiO.sub.2 49 49 49 48 49 49 49 Al.sub.2O.sub.3 11 11 11 11 11 11 11 B.sub.2O.sub.3 6 6 6 6 6 6 6 MgO 17 17 17 17 17 17 17 CaO 4 4 4 3 4 4 4 SrO 5 5 5 7 6 6 6 BaO 2 3 3 3 2 2 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 2 2 2 Gd.sub.2O.sub.3 2 2 2 2 2 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 15 15 15 15 15 15 15 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 4 4 4 4 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.44 0.45 0.45 0.46 0.45 0.45 0.48 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.34 0.34 0.34 0.34 0.34 0.34 MgO/RO 0.61 0.59 0.59 0.57 0,59 0.59 0.57 N 11 10 10 10 10 10 9 Young's modulus E (GPa) 99 97 98 97 98 99 97 Coefficient of thermal expansion (ppm/ C.) 5.58 5.66 5.71 5.80 5.66 5.71 5.79 Liquidus temperature TL ( C.) 1224 1217 1219 1213 1219 1222 1213 Young's modulus parameter Y 1.00 0.97 0.99 0.98 0.99 1.00 0.97 Liquidus parameter L 9.2 9.3 9.2 9.0 9.1 8.9 9.0 Thermal expansion parameter C 1.11 1.12 1.13 1.16 1.13 1.13 1.15 Glass transition point ( C.) 702 697 694 698 701 699 693 Density (g/cm.sup.3) 3.11 3.13 3.14 3.15 3.11 3.13 3.15 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.27 0.08 0.15 0.10 0.08 0.15 0.03 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) 41100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00097 TABLE 97 Example Example Example Example Example Example Example (mol %) 678 679 680 681 682 683 684 SiO.sub.2 49 48 49 49 49 49 49 Al.sub.2O.sub.3 11 11 11 11 12 12 12 B.sub.2O.sub.3 6 6 6 6 6 6 6 MgO 17 17 17 17 17 17 17 CaO 4 4 4 4 2 2 2 SrO 6 6 7 7 5 6 6 BaO 3 3 2 3 3 3 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 4 2 2 2 2 2 2 Gd.sub.2O.sub.3 2 2 2 2 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 15 13 15 13 16 16 16 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 2 4 2 4 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.46 0.46 0.46 0.44 0.45 0.45 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.34 0.34 0.34 0.35 0.35 0.35 MgO/RO 0.57 0.57 0.57 0.55 0.63 0.61 0.61 N 8 10 9 9 11 10 10 Young's modulus E (GPa) 97 96 97 96 99 98 99 Coefficient of thermal expansion (ppm/ C.) 5.57 5.45 5.79 5.58 5.49 5.58 5.63 Liquidus temperature TL ( C.) 1221 1222 1220 1223 1224 1223 1221 Young's modulus parameter Y 0.98 0.96 0.99 0.96 1.00 0.98 1.00 Liquidus parameter L 9.2 9.5 8.7 9.2 9.5 9.3 9.2 Thermal expansion parameter C 1.13 1.09 1.15 1.12 1.08 1.10 1.11 Glass transition point ( C.) 691 696 697 691 700 699 699 Density (g/cm.sup.3) 3.05 2.96 3.13 2.97 3.14 3.14 3.15 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.11 0.38 0.03 0.27 0.28 0.09 0.16 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00098 TABLE 98 Example Example Example Example Example Example Example (mol %) 685 686 687 688 689 690 691 SiO.sub.2 49 49 49 49 49 49 49 Al.sub.2O.sub.3 12 12 12 12 12 12 10 B.sub.2O.sub.3 6 6 6 6 6 6 6 MgO 17 17 17 17 17 17 17 CaO 2 3 3 3 3 3 4 SrO 7 5 5 5 6 6 7 BaO 3 2 3 3 2 2 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 2 2 2 2 Gd.sub.2O.sub.3 2 2 2 2 2 2 La.sub.2O.sub.3 2 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 16 16 16 16 16 16 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 4 4 4 4 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.44 0.45 0.45 0.45 0.45 0.46 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.35 0.35 0.35 0.35 0.35 0.33 MgO/RO 0.59 0.63 0.61 0.61 0.61 0.61 0.55 N 9 11 10 10 10 10 9 Young's modulus E (GPa) 97 100 98 99 98 99 96 Coefficient of thermal expansion (ppm/ C.) 5.71 5.44 5.53 5.58 5.52 5.58 5.90 Liquidus temperature TL ( C.) 1223 1217 1213 1213 1215 1216 1213 Young's modulus parameter Y 0.98 1.01 0.98 0.99 0.99 1.01 0.97 Liquidus parameter L 9.0 9.4 9.4 9.3 9.2 9.0 8.7 Thermal expansion parameter C 1.12 1.08 1.09 1.10 1.10 1.11 1.18 Glass transition point ( C.) 698 704 699 699 703 703 689 Density (g/cm.sup.3) 3.16 3.11 3.12 3.14 3.11 3.12 3.14 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.02 0.28 0.10 0.17 0.10 0.17 0.07 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00099 TABLE 99 Example Example Example Example Example Example Example (mol %) 692 693 694 695 696 697 698 SiO.sub.2 49 49 49 49 49 49 49 Al.sub.2O.sub.3 12 12 12 12 12 12 12 B.sub.2O.sub.3 6 6 6 6 6 6 6 MgO 17 17 17 17 17 17 17 CaO 3 3 3 3 3 4 4 SrO 6 6 7 7 7 5 5 BaO 3 3 2 3 3 2 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 TiO.sub.2 1 1 1 Y.sub.2O.sub.3 2 2 2 2 2 2 2 Gd.sub.2O.sub.3 2 2 2 2 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 16 14 16 14 14 16 16 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 2 4 2 2 4 4 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.46 0.46 0.46 0.46 0.45 0.46 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.35 0.35 0.35 0.35 0.35 0.35 MgO/RO 0.59 0.59 0.59 0.57 0.57 0.61 0.59 N 9 10 9 9 9 10 9 Young's modulus E (GPa) 97 97 97 95 96 98 97 Coefficient of thermal expansion (ppm/ C.) 5.66 5.32 5.66 5.40 5.45 5.48 5.61 Liquidus temperature TL ( C.) 1210 1216 1217 1217 1221 1223 1218 Young's modulus parameter Y 0.98 0.97 0.99 0.95 0.97 0.99 0.98 Liquidus parameter L 9.1 9.6 8.9 9.5 9.3 9.3 9.2 Thermal expansion parameter C 1.12 1.07 1.12 1.08 1.09 1.09 1.11 Glass transition point ( C.) 698 699 701 698 697 701 693 Density (g/cm.sup.3) 3.14 2.95 3.12 2.95 2.97 3.09 3.13 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.02 0.40 0.02 0.21 0.28 0.10 0.01 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00100 TABLE 100 Example Example Example Example Example Example Example (mol %) 699 700 701 702 703 704 705 SiO.sub.2 49 49 49 50 50 50 50 Al.sub.2O.sub.3 12 12 12 10 10 10 10 B.sub.2O.sub.3 6 6 6 6 6 6 6 MgO 17 17 17 21 21 21 21 CaO 4 4 4 2 2 2 2 SrO 6 6 6 2 2 2 2 BaO 2 3 3 4 4 4 4 Li.sub.2O Na.sub.2O K.sub.2O ZnO 1 P.sub.2O.sub.5 1 ZrO.sub.2 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 Y.sub.2O.sub.3 2 2 2 2 2 2 2 Gd.sub.2O.sub.3 2 La.sub.2O.sub.3 WO.sub.3 1 Ta.sub.2O.sub.5 1 Al.sub.2O.sub.3 + rare earth oxide 16 14 14 12 12 12 12 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4 2 2 3 2 2 2 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.46 0.46 0.46 0.44 0.44 0.44 0.44 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.35 0.35 0.36 0.36 0.36 0.36 MgO/RO 0.59 0.57 0.57 0.72 0.72 0.72 0.70 N 9 9 9 11 11 11 11 Young's modulus E (GPa) 98 95 96 98 98 96 97 Coefficient of thermal expansion (ppm/ C.) 5.61 5.35 5.40 5.00 5.06 5.09 5.05 Liquidus temperature TL ( C.) 1220 1221 1225 1194 1189 1189 1187 Young's modulus parameter Y 0.99 0.95 0.96 0.97 0.96 0.96 0.96 Liquidus parameter L 9.0 9.6 9.5 9.9 9.7 9.7 9.8 Thermal expansion parameter C 1.12 1.07 1.08 0.99 1.01 1.01 1.00 Glass transition point ( C.) 697 696 692 705 705 705 705 Density (g/cm.sup.3) 3.11 2.94 2.96 3.01 2.97 2.95 2.94 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.01 0.22 0.29 0.97 0.64 0.64 0.64 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00101 TABLE 101 Example Example Example Example Example Example Example (mol %) 706 707 708 709 710 711 712 SiO.sub.2 51.5 51.5 51.5 51.5 51.5 51.5 51.5 Al.sub.2O.sub.3 12 12.5 12.5 13 13 13 13.5 B.sub.2O.sub.3 8.5 8 8.5 7.5 8 8.5 7 MgO 22 22 21.5 22 21.5 21 22 CaO 1 1 1 1 1 1 1 SrO 1 1 1 1 1 1 1 BaO 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13.5 14 14 14.5 14.5 14.5 15 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + 0.41 0.42 0.41 0.42 0.42 0.41 0.42 Al.sub.2O.sub.3 + RO) (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.37 0.36 0.37 0.37 0.36 0.38 MgO/RO 0.90 0.90 0.90 0.90 0.90 0.89 0.90 N 10 10 10 10 10 10 10 Young's modulus E (GPa) 98 98 98 99 98 98 99 Coefficient of thermal expansion (ppm/ C.) 4.15 4.13 4.11 4.11 4.09 4.06 4.10 Liquidus temperature TL ( C.) 1208 1217 1219 1220 1219 1217 1218 Young's modulus parameter Y 0.97 0.97 0.97 0.98 0.97 0.97 0.99 Liquidus parameter L 9.5 9.7 9.6 9.8 9.7 9.7 9.9 Thermal expansion parameter C 0.83 0.83 0.82 0.83 0.82 0.82 0.82 Glass transition point ( C.) 718 720 720 722 722 722 725 Density (g/cm.sup.3) 2.71 2.72 2.71 2.72 2.72 2.71 2.73 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.9< 0.10< 0.11< 0.12< 0.13< 0.14< 0.15< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.93 0.92 0.91 0.92 0.91 0.90 0.92 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) T.sub.3 ( C.) T.sub.4 ( C.) Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00102 TABLE 102 Example Example Example Example Example Example Example (mol %) 713 714 715 716 717 718 719 SiO.sub.2 51.5 51.5 52 52 52 52 52 Al.sub.2O.sub.3 13.5 13.5 11.5 12 12 12.5 12.5 B.sub.2O.sub.3 7.5 8 8.5 8 8.5 7.5 8 MgO 21.5 21 22 22 21.5 22 21.5 CaO 1 1 1 1 1 1 1 SrO 1 1 1 1 1 1 1 BaO 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 15 15 13 13.5 13.5 14 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + 0.42 0.42 0.41 0.41 0.41 0.42 0.41 Al.sub.2O.sub.3 + RO) (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.36 0.36 0.36 0.37 0.36 MgO/RO 0.90 0.89 0.90 0.90 0.90 0.90 0.90 N 10 10 10 10 10 10 10 Young's modulus E (GPa) 99 98 97 98 97 98 98 Coefficient of thermal expansion (ppm/ C.) 4.07 4.05 4.15 4.14 4.11 4.12 4.10 Liquidus temperature TL ( C.) 1220 1216 1218 1218 1217 1230 1228 Young's modulus parameter Y 0.98 0.97 0.96 0.97 0.96 0.98 0.97 Liquidus parameter L 9.9 9.8 9.5 9.6 9.6 9.7 9.7 Thermal expansion parameter C 0.82 0.81 0.83 0.83 0.82 0.83 0.82 Glass transition point ( C.) 725 725 718 718 718 720 720 Density (g/cm.sup.3) 2.72 2.72 2.71 2.71 2.71 2.72 2.71 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.16< 0.17< 0.18< 0.19< 0.20< 0.21< 0.22< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.91 0.90 0.97 0.97 0.96 0.96 0.95 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) T.sub.3 ( C.) T.sub.4 ( C.) Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00103 TABLE 103 Example Example Example Example Example Example Example (mol %) 720 721 722 723 724 725 726 SiO.sub.2 52 52 52 52 52 52 52 Al.sub.2O.sub.3 12.5 13 13 13 13.5 13.5 13.5 B.sub.2O.sub.3 8.5 7 7.5 8 6.5 7 7.5 MgO 21 22 21.5 23 22 21.5 21 CaO 1 1 1 1 1 1 1 SrO 1 1 1 1 1 1 1 BaO 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14 14.5 14.5 14.5 15 15 15 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + 0.41 0.42 0.42 0.41 0.42 0.42 0.42 Al.sub.2O.sub.3 + RO) (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.37 0.37 0.36 0.38 0.37 0.37 MgO/RO 0.89 0.90 0.90 0.89 0.90 0.90 0.89 N 10 10 10 10 10 10 10 Young's modulus E (GPa) 97 99 98 98 99 99 98 Coefficient of thermal expansion (ppm/ C.) 4.07 4.11 4.08 4.06 4.09 4.06 4.04 Liquidus temperature TL ( C.) 1225 1226 1228 1224 1227 1225 1225 Young's modulus parameter Y 0.96 0.98 0.98 0.97 0.99 0.98 0.98 Liquidus parameter L 9.7 9.8 9.8 9.8 10.0 9.9 9.9 Thermal expansion parameter C 0.82 0.82 0.82 0.81 0.82 0.81 0.81 Glass transition point ( C.) 720 722 722 722 727 725 725 Density (g/cm.sup.3) 2.71 2.72 2.72 2.71 2.73 2.72 2.72 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.23< 0.24< 0.25< 0.26< 0.27< 0.28< 0.29< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 0.94 0.96 0.95 0.94 0.95 0.94 0.93 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) T.sub.3 ( C.) T.sub.4 ( C.) Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00104 TABLE 104 Example Example Example Example Example Example Example (mol %) 727 728 729 730 731 732 733 SiO.sub.2 52.5 52.5 52.5 52.5 52.5 52.5 52.5 Al.sub.2O.sub.3 11.5 11.5 12 12 12 12.5 12.5 B.sub.2O.sub.3 8 8.5 7.5 8 8.5 7 8 MgO 22 21.5 22 21.5 21 22 21 CaO 1 1 1 1 1 1 1 SrO 1 1 1 1 1 1 1 BaO 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13 13.5 13.5 13.5 14 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + 0.41 0.40 0.41 0.41 0.40 0.41 0.41 Al.sub.2O.sub.3 + RO) (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.35 0.36 0.36 0.35 0.37 0.36 MgO/RO 0.90 0.90 0.90 0.90 0.89 0.90 0.89 N 10 10 10 10 10 10 10 Young's modulus E (GPa) 97 97 98 97 97 98 97 Coefficient of thermal expansion (ppm/ C.) 4.15 4.12 4.13 4.10 4.08 4.11 4.06 Liquidus temperature TL ( C.) 1223 1222 1224 1222 1220 1231 1230 Young's modulus parameter Y 0.96 0.96 0.97 0.96 0.96 0.98 0.97 Liquidus parameter L 9.6 9.5 9.7 9.6 9.6 9.8 9.7 Thermal expansion parameter C 0.83 0.82 0.83 0.82 0.82 0.82 0.81 Glass transition point ( C.) 718 718 718 718 718 720 720 Density (g/cm.sup.3) 2.71 2.70 2.71 2.71 2.70 2.72 2.71 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.30< 0.31< 0.32< 0.33< 0.34< 0.35< 0.36< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 1.01 1.00 1.00 0.99 0.98 1.00 0.98 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) T.sub.3 ( C.) T.sub.4 ( C.) Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00105 TABLE 105 Example Example Example Example Example Example Example (mol %) 734 735 736 737 738 739 740 SiO.sub.2 52.5 52.5 52.5 52.5 52.5 53 53 Al.sub.2O.sub.3 13 13 13 13.5 13.5 11.5 11.5 B.sub.2O.sub.3 6.5 7 7.5 6.5 7 7.5 8 MgO 22 21.5 21 21.5 21 22 21.5 CaO 1 1 1 1 1 1 1 SrO 1 1 1 1 1 1 1 BaO 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 1 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14.5 14.5 14.5 15 15 13 13 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + 0.42 0.41 0.41 0.42 0.41 0.40 0.40 Al.sub.2O.sub.3 + RO) (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.37 0.36 0.37 0.37 0.36 0.35 MgO/RO 0.90 0.90 0.89 0.90 0.89 0.90 0.90 N 10 10 10 10 10 10 10 Young's modulus E (GPa) 99 99 98 99 99 97 97 Coefficient of thermal expansion (ppm/ C.) 4.10 4.07 4.05 4.06 4.03 4.14 4.11 Liquidus temperature TL ( C.) 1230 1229 1229 1229 1224 1225 1223 Young's modulus parameter Y 0.99 0.98 0.97 0.99 0.98 0.97 0.96 Liquidus parameter L 9.9 9.9 9.8 10.0 10.0 9.8 9.8 Thermal expansion parameter C 0.82 0.82 0.81 0.81 0.81 0.83 0.82 Glass transition point ( C.) 724 722 722 727 725 718 718 Density (g/cm.sup.3) 2.72 2.72 2.71 2.73 2.72 2.71 2.70 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.37< 0.38< 0.39< 0.40< 0.41< 0.42< 0.43< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 1.00 0.99 0.98 0.98 0.97 1.04 1.04 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) T.sub.3 ( C.) T.sub.4 ( C.) Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00106 TABLE 106 Example Example Example Example Example Example Example (mol %) 741 742 743 744 745 746 747 SiO.sub.2 53 53 53 53 53 53 53 Al.sub.2O.sub.3 11.5 12 12 12 12.5 12.5 12.5 B.sub.2O.sub.3 8.5 7 7.5 8 6.5 7 7.5 MgO 21 22 21.5 21 22 21.5 21 CaO 1 1 1 1 1 1 1 SrO 1 1 1 1 1 1 1 BaO 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 13 13.5 13.5 13.5 14 14 14 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + 0.40 0.41 0.40 0.40 0.41 0.41 0.40 Al.sub.2O.sub.3 + RO) (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.35 0.36 0.36 0.35 0.37 0.36 0.36 MgO/RO 0.89 0.90 0.90 0.89 0,90 0.90 0.89 N 10 10 10 10 10 10 10 Young's modulus E (GPa) 96 98 97 97 99 98 98 Coefficient of thermal expansion (ppm/ C.) 4.09 4.12 4.10 4.07 4.11 4.08 4.05 Liquidus temperature TL ( C.) 1220 1222 1224 1221 1231 1231 1231 Young's modulus parameter Y 0.95 0.97 0.97 0.96 0.98 0.98 0.97 Liquidus parameter L 9.6 9.8 9.7 9.7 9.9 9.8 9.8 Thermal expansion parameter C 0.82 0.82 0.82 0.81 0.82 0.82 0.81 Glass transition point ( C.) 718 719 718 718 722 721 720 Density (g/cm.sup.3) 2.70 2.72 2.71 2.70 2.72 2.72 2.71 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.44< 0.45< 0.46< 0.47< 0.48< 0.49< 0.50< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 1.03 1.04 1.03 1.02 1.04 1.03 1.02 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) T.sub.3 ( C.) T.sub.4 ( C.) Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00107 TABLE 107 Example Example Example Example Example Example Example (mol %) 748 749 750 751 752 753 754 SiO.sub.2 53 53 53 53.5 53.5 53.5 53.5 Al.sub.2O.sub.3 13 13 13.5 11.5 11.5 11.5 12 B.sub.2O.sub.3 6.5 7 6.5 7 7.5 8 6.5 MgO 21.5 21 21 22 21.5 21 22 CaO 1 1 1 1 1 1 1 SrO 1 1 1 1 1 1 1 BaO 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 1 1 Y.sub.2O.sub.3 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 14.5 14.5 15 13 13 13 13.5 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + 0.41 0.41 0.41 0.40 0.40 0.40 0.41 Al.sub.2O.sub.3 + RO) (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.37 0.36 0.37 0.36 0.35 0.35 0.36 MgO/RO 0.90 0.89 0.89 0.90 0.90 0.89 0.90 N 10 10 10 10 10 10 10 Young's modulus E (GPa) 99 98 99 98 97 97 98 Coefficient of thermal expansion (ppm/ C.) 4.06 4.04 4.02 4.13 4.10 4.08 4.11 Liquidus temperature TL ( C.) 1231 1226 1227 1221 1224 1220 1222 Young's modulus parameter Y 0.98 0.98 0.98 0.97 0.96 0.96 0.98 Liquidus parameter L 10.0 9.9 10.0 9.7 9.7 9.6 9.8 Thermal expansion parameter C 0.81 0.81 0.81 0.82 0.82 0.81 0.82 Glass transition point ( C.) 724 722 727 719 718 718 721 Density (g/cm.sup.3) 2.72 2.72 2.72 2.71 2.71 2.70 2.72 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.51< 0.52< 0.53< 0.54< 0.55< 0.56< 0.57< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 Acid resistance parameter T 1.02 1.01 1.01 1.08 1.07 1.06 1.08 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 80 80 T.sub.2 ( C.) T.sub.3 ( C.) T.sub.4 ( C.) Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00108 TABLE 108 Example Example Example Example Example (mol %) 755 756 757 758 759 SiO.sub.2 53.5 53.5 53.5 53.5 53.5 Al.sub.2O.sub.3 12 12 12.5 12.5 13 B.sub.2O.sub.3 7 7.5 6.5 7 6.5 MgO 21.5 21 21.5 21 21 CaO 1 1 1 1 1 SrO 1 1 1 1 1 BaO 0.5 0.5 0.5 0.5 0.5 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 TiO.sub.2 1 1 1 1 1 Y.sub.2O.sub.3 1.5 1.5 1.5 1.5 1.5 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.3 Al.sub.2O.sub.3 + rare earth oxide 13.5 13.5 14 14 14.5 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 1.5 1.5 1.5 1.5 1.5 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.40 0.40 0.41 0.40 0.41 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.36 0.35 0.36 0.36 0.36 MgO/RO 0.90 0.89 0.90 0.89 0.89 N 10 10 10 10 10 Young's modulus E (GPa) 98 97 98 98 98 Coefficient of thermal expansion (ppm/ C.) 4.09 4.06 4.07 4.05 4.03 Liquidus temperature TL ( C.) 1221 1221 1232 1227 1228 Young's modulus parameter Y 0.97 0.96 0.98 0.97 0.98 Liquidus parameter L 9.8 9.8 9.9 9.9 10.0 Thermal expansion parameter C. 0.82 0.81 0.81 0.81 0.81 Glass transition point ( C.) 719 719 723 721 725 Density (g/cm.sup.3) 2.71 2.71 2.72 2.71 2.72 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2< 2< 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.58< 0.59< 0.60< 0.61< 0.62< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 883 88 88 88 88 Acid resistance parameter T 1.07 1.06 1.07 1.06 1.05 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 80 80 T.sub.2 ( C.) T.sub.3 ( C.) T.sub.4 ( C.) Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00109 TABLE 109 Example Example Example Example Example Example Example (mol %) 760 761 762 763 764 765 766 SiO.sub.2 63.2 61.8 43 42.8 65.7 60.7 71.8 Al.sub.2O.sub.3 11.6 10.6 13 8.1 12.1 13.3 6 B.sub.2O.sub.3 1.4 0.9 0.9 MgO 14.9 15.9 8.3 10.8 13.3 CaO 8.7 8.7 10.4 10.7 3.1 SrO 9 BaO 10.1 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 2.4 0.8 TiO.sub.2 8 5.7 Y.sub.2O.sub.3 1.4 1.4 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 MnO 36 32.7 Al.sub.2O.sub.3 + rare earth oxide 13 12 13 8.1 12.1 13.3 6 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + 1.4 1.4 0 0 0 0 0 Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + 0.36 0.36 0.53 0.53 0.34 0.38 0.28 Al.sub.2O.sub.3 + RO) (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + 0.30 0.30 0.23 0.28 0.26 0.30 0.08 Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) MgO/RO 0.63 0.65 0.00 0.20 0.51 0.55 0.00 N 5 6 3 5 5 6 5 Young's modulus E (GPa) 95 94 101 102 90 95 75 Coefficient of thermal expansion 4.39 4.72 4.8 5.2 4 4.3 5.83 (ppm/ C.) Liquidus temperature TL ( C.) 1191 1194 1120 1150 1235 1236 1260 Young's modulus parameter Y 0.96 0.95 1.03 1.07 0.90 0.95 0.72 Liquidus parameter L 10.9 10.6 7.9 7.1 11.2 11.1 11.3 Thermal expansion parameter C 0.82 0.85 1.29 1.36 0.77 0.83 1.01 Glass transition point ( C.) 773 750 Density (g/cm.sup.3) 2.67 2.68 3.24 3.19 2.53 2.99 Liquidus viscosity log .sub.L(dPa .Math. s) 4.27 K.sub.IC (MPa .Math. m.sup.0.5) <0.8 Transmittance (%) @308 nm, 0.7 mmt 30 30 <0.1 <0.1 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 70 70 <0.1 <0.1 70 70 70 Transmittance (%) @550 nm, 0.7 mmt 85 85 <0.1 <0.1 85 85 85 Transmittance (%) @1064 nm, 0.7 mmt 80 80 65 65 80 80 80 T.sub.2 ( C.) 1583 1506 <1400 <1400 1630 1500< 1641 T.sub.3 ( C.) 1342 1294 1341 1413 T.sub.4 ( C.) 1216 1174 1239 1255 Deflection determination x x x Manufacturability determination x x x x Transmission ability determination x x

TABLE-US-00110 TABLE 110 Example Example Example (mol %) 767 768 769 SiO.sub.2 67 52.7 50 Al.sub.2O.sub.3 7.7 12 11 B.sub.2O.sub.3 6.1 MgO 3.6 21.2 15.2 CaO 4 14.1 23.8 SrO 4.7 BaO 7 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 TiO.sub.2 Y.sub.2O.sub.3 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 MnO Al.sub.2O.sub.3 + rare earth oxide 7.7 12 11 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 0 0 0 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.29 0.47 0.50 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.13 0.39 0.34 MgO/RO 0.19 0.60 0.39 N 7 4 4 Young's modulus E (GPa) 76 100 100 Coefficient of thermal expansion (ppm/ C.) 4.83 5.1 6 Liquidus temperature TL ( C.) 1255 1305 1335 Young's modulus parameter Y 0.73 1.00 0.98 Liquidus parameter L 10.7 10.5 10.6 Thermal expansion parameter C. 0.88 1.01 1.19 Glass transition point ( C.) 690 754 745 Density (g/cm.sup.3) 2.77 2.71 2.77 Liquidus viscosity log .sub.L (dPa .Math. s) 2.33 1.94 K.sub.IC (Mpa .Math. m.sup.0.5) <0.8 Transmittance (%) @308 nm, 0.7 mmt 30 30 30 Transmittance (%) @350 nm, 0.7 mmt 70 70 70 Transmittance (%) @550 nm, 0.7 mmt 85 85 85 Transmittance (%) @1064 nm, 0.7 mmt 80 80 80 T.sub.2 ( C.) 1629 1367 1321 T.sub.3 ( C.) 1388 T.sub.4 ( C.) 1225 1146 1091 Deflection determination x Manufacturability determination x x x Transmission ability determination

TABLE-US-00111 TABLE 111 Example Example Example Example Example Example Example Example (mol %) 770 771 772 773 774 775 776 777 SiO.sub.2 48 48.8 49 49.1 50 50 50 50 Al.sub.2O.sub.3 8.7 7.2 10.1 10 10 10 8 8 B.sub.2O.sub.3 6.9 6.8 6.7 6.6 6 6 6 6 MgO 17.7 18.3 18.5 18.3 20 18 22 20 CaO 0.5 2.8 2.2 0.5 2 2 2 2 SrO 0.3 1.9 3.6 1.4 2 2 2 2 BaO 3.5 3.2 1.2 1.1 4 4 4 4 Li.sub.2O 1.3 2.8 1.4 2.8 Na.sub.2O 2.7 0 1.6 K.sub.2O 0.9 0.5 ZnO 4.2 2.1 0.4 P.sub.2O.sub.5 ZrO.sub.2 0.6 1.2 0.8 0.9 1 1 1 1 TiO.sub.2 2.4 1.7 0.4 0.7 3 5 3 5 Y.sub.2O.sub.3 2.5 1.6 2.9 4.1 2 2 2 2 Gd.sub.2O.sub.3 La.sub.2O.sub.3 0.7 1.6 0.7 3.6 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11.9 10.4 13.7 17.7 12.0 12.0 10.0 10.0 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 3.2 3.2 3.6 7.7 2.0 2.0 2.0 2.0 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.42 0.42 0.42 0.39 0.43 0.42 0.43 0.42 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.32 0.31 0.34 0.34 0.35 0.33 0.35 0.33 MgO/RO 0.68 0.65 0.73 0.84 0.71 0.69 0.73 0.71 N 13 13 13 13 10 10 10 10 Young's modulus E (GPa) 97 101 98 106 97 97 97 97 Coefficient of thermal expansion (ppm/ C.) 5.90 5.82 6.00 5.83 5.08 5.17 5.22 4.97 Liquidus temperature TL ( C.) 1135 1135 1145 1095 1155 1185 1185 1155 Young's modulus parameter Y 0.98 1.00 0.99 1.08 0.95 0.95 0.95 0.95 Liquidus parameter L 9.2 8.7 8.8 8.5 10.3 10.8 10.0 10.4 Thermal expansion parameter C 1.25 1.13 1.22 1.12 0.99 0.98 1.02 1.02 Glass transition point ( C.) 720 Density (g/cm.sup.3) 3.01 3.08 2.92 3.21 2.94 2.94 2.95 3.00 Liquidus viscosity log .sub.L(dPa .Math. s) 2.5< 2.5< 3.09 2.5< 3.2* 2.92 2.9* 3.3* K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 0.1 0.1 5 5 0.1 0< 0.1 0< Transmittance (%) @350 nm, 0.7 mmt 75 75 80 80 80 75 80 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 88 Transmittance (%) @1064 nm, 0.7 mmt 88 88 88 88 88 88 88 88 T.sub.2 ( C.) <1350 <1350 <1350 <1350 <1350 1317 <1350 <1350 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 1175 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 1076 <1100 <1100 Sulfuric acid resistance (amount of weight loss (mg/cm.sup.2)) 0.023 0.010 0.017 0.009 Sulfuric acid resistance (transmission ability) x x x x Sulfuric acid resistance parameter S 2.13 3.48 2.62 3.66 Acid resistance parameter T 0.44 0.59 0.41 0.52 0.83 0.96 0.88 1.02 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00112 TABLE 112 Example Example Example Example Example Example Example Example (mol %) 778 779 780 781 782 783 784 785 SiO.sub.2 53 53 50 50 50 50 51 50 Al.sub.2O.sub.3 9 9.5 10 9.33 8 8 8 8 B.sub.2O.sub.3 6 6 6 6 6 6 6 6 MgO 17 17 21 18.7 19 20.5 19.5 20.5 CaO 2 2 2 2 3 4 2.5 4 SrO 2 2 2 2 3 3 3 3 BaO 4 4 4 4 2 0.5 2 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1.5 1 1 2 1 1 1 TiO.sub.2 2 0.5 1 5 5 5 5 5 Y.sub.2O.sub.3 4 4 2 2 2 2 2 2.5 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 1 Al.sub.2O.sub.3 + rare earth oxide 13.0 13.5 12.0 11.3 10.0 10.0 10.0 10.5 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 4.0 4.0 3.0 2.0 2.0 2.0 2.0 2.5 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.39 0.39 0.44 0.42 0.41 0.42 0.41 0.42 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.31 0.31 0.36 0.33 0.33 0.34 0.33 0.34 MgO/RO 0.68 0.68 0.72 0.70 0.70 0.73 0.72 0.75 N 10 10 11 10 10 10 10 9 Young's modulus E (GPa) 97 97 99 96 99 100 97 101 Coefficient of thermal expansion (ppm/ C.) 5.02 4.99 4.98 5.01 5.12 5.05 5.02 5.04 Liquidus temperature TL ( C.) 1145 1175 1175 1155 1235 1185 1140 1155 Young's modulus parameter Y 0.96 0.97 0.97 0.95 0.98 0.99 0.96 1.00 Liquidus parameter L 10.1 9.9 9.9 10.6 10.2 9.9 10.1 9.8 Thermal expansion parameter C 1.00 1.01 0.99 0.99 1.03 1.01 1.00 1.02 Glass transition point ( C.) 721 720 713 715 719 Density (g/cm.sup.3) 3.00 3.00 3.04 2.93 2.94 2.87 2.89 2.88 Liquidus viscosity log .sub.L(dPa .Math. s) 3.4< 3.1< 3.08 3.11 2.5* 2.70 3.2 2.95 K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 30 30 30 0< 0< 0< 0< 0< Transmittance (%) @350 nm, 0.7 mmt 85 85 85 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 90 90 90 88 88 88 88 88 Transmittance (%) @1064 nm, 0.7 mmt 90 90 90 88 88 88 88 88 T.sub.2 ( C.) <1400 <1400 1323 1310 <1350 1286 1304 1285 T.sub.3 ( C.) <1250 <1250 1184 1167 <1200 1150 1162 1150 T.sub.4 ( C.) <1150 <1150 1088 1069 <1100 1056 1065 1057 Sulfuric acid resistance (amount of weight loss (mg/cm.sup.2)) 0.014 0.023 0.011 0.010 0.005 0.009 0.006 0.010 Sulfuric acid resistance (transmission ability) x x x x Sulfuric acid resistance parameter S 2.91 2.12 3.34 3.50 5.33 3.96 6.63 7.17 Acid resistance parameter T 0.89 0.82 0.97 0.98 1.16 1.05 1.10 1.05 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00113 TABLE 113 Example Example Example Example Example Example Example Example (mol %) 786 787 788 789 790 791 792 793 SiO.sub.2 52.6 50.5 52 50 50 50 55 54 Al.sub.2O.sub.3 7.7 7.75 6 6.5 7.5 5.5 6.5 6.5 B.sub.2O.sub.3 3.8 6.25 5.5 4 6 6 3 3 MgO 19.6 15 15 20 18 18 20 18 CaO 2.9 1 3 6 3 3 5 1 SrO 3.8 3 8 3 7 4 3 10 BaO 3 Li.sub.2O Na.sub.2O K.sub.2O ZnO 1 1 P.sub.2O.sub.5 ZrO.sub.2 1.0 0.5 1 1 0.5 1.5 1.5 1 TiO.sub.2 4.8 5 4 5 2 5 1 1 Y.sub.2O.sub.3 3.8 3 3.5 4.5 3 2.5 3 5.5 Gd.sub.2O.sub.3 La.sub.2O.sub.3 3 3 3.5 2 WO.sub.3 Ta.sub.2O.sub.5 1 2 Al.sub.2O.sub.3 + rare earth oxide 11.5 13.8 9.5 11.0 13.5 11.5 11.5 12.0 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 3.8 7.0 5.5 4.5 6.0 6.0 5.0 5.5 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.39 0.38 0.38 0.42 0.42 0.39 0.39 0.40 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.33 0.29 0.27 0.33 0.31 0.30 0.31 0.30 MgO/RO 0.75 0.65 0.58 0.69 0.64 0.69 0.71 0.62 N 9 13 10 9 10 11 10 9 Young's modulus E (GPa) 104 101 107 101 103 105 103 103 Coefficient of thermal expansion (ppm/ C.) 5.10 5.52 5.38 5.60 5.91 5.78 5.43 5.83 Liquidus temperature TL ( C.) 1175 1145 1275 1155 1135 1215 1195 1235 Young's modulus parameter Y 1.03 1.00 1.01 1.04 1.03 1.04 1.04 1.05 Liquidus parameter L 9.9 9.9 9.2 9.8 8.3 9.0 9.1 8.5 Thermal expansion parameter C 1.03 1.08 1.12 1.12 1.19 1.15 1.09 1.19 Glass transition point ( C.) Density (g/cm.sup.3) 2.96 3.34 3.05 3.23 3.22 3.25 3.08 3.16 Liquidus viscosity log .sub.L(dPa .Math. s) 2.98 2< 2.12 2.84 2.95 2.08 2< 2< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 0< 0< 0< 0< 5 0< 30 5 Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 85 75 85 85 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 88 Transmittance (%) @1064 nm, 0.7 mmt 88 88 88 88 88 88 88 88 T.sub.2 ( C.) 1306 <1350 1294 1258 1250 1256 <1300 <1300 T.sub.3 ( C.) 1174 <1200 1163 1139 1130 1117 <1200 <1200 T.sub.4 ( C.) 1082 <1100 1073 1055 1047 1031 <1100 <1100 Sulfuric acid resistance (amount of weight loss (mg/cm.sup.2)) 0.004 0.006 0.001 0.008 0.088 0.016 0.005 0.023 Sulfuric acid resistance (transmission ability) x x Sulfuric acid resistance parameter S 6.33 7.50 8.99 11.25 7.86 6.73 8.63 6.14 Acid resistance parameter T 1.20 1.09 1.51 0.99 0.50 0.99 1.08 0.81 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00114 TABLE 114 Example Example Example Example Example Example Example Example (mol %) 794 795 796 797 798 799 800 801 SiO.sub.2 53 52.6 52.6 52.7 50 50 50 50 Al.sub.2O.sub.3 7 7.7 7.7 8.2 7.1 8 8 8 B.sub.2O.sub.3 3.5 3.8 3.8 3.9 5.9 6 6 6 MgO 16 19.6 19.6 18.7 20.2 20.5 20.5 20 CaO 9 2.9 2.6 2.3 3.5 2 2.5 3 SrO 3.8 4.1 5.6 3.6 5 4.5 4 BaO 0.5 0.5 0.5 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 1 TiO.sub.2 1 4.8 4.8 4.5 5.2 5 5 5 Y.sub.2O.sub.3 6 3.8 3.8 3.1 3.5 2 2 2.5 Gd.sub.2O.sub.3 La.sub.2O.sub.3 3.5 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 16.5 11.5 11.5 11.3 10.6 10.0 10.0 10.5 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 9.5 3.8 3.8 3.1 3.5 2.0 2.0 2.5 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.38 0.39 0.39 0.40 0.41 0.42 0.42 0.42 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.29 0.33 0.33 0.32 0.33 0.34 0.34 0.33 MgO/RO 0.64 0.75 0.75 0.70 0.74 0.73 0.73 0.73 N 9 9 9 9 9 10 10 10 Young's modulus E (GPa) 110 104 102 104 103 100 100 101 Coefficient of thermal expansion (ppm/ C.) 5.86 5.10 5.05 5.06 5.23 5.06 5.07 5.10 Liquidus temperature TL ( C.) 1245 1165 1185 1175 1155 1165 1165 1155 Young's modulus parameter Y 1.10 1.03 1.03 1.02 1.01 0.99 0.99 0.99 Liquidus parameter L 9.2 10.0 9.9 9.8 9.7 9.6 9.7 9.8 Thermal expansion parameter C 1.18 1.03 1.03 1.04 1.05 1.03 1.03 1.03 Glass transition point ( C.) Density (g/cm.sup.3) 3.33 2.97 2.97 2.96 2.95 2.90 2.89 2.91 Liquidus viscosity log .sub.L(dPa .Math. s) 2< 2.5< 2.5< 2.5< 2.5< 2.5< 2.5< 2.5< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 5 0< 0< 0< 0< 0< 0< 0< Transmittance (%) @350 nm, 0.7 mmt 85 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 88 Transmittance (%) @1064 nm, 0.7 mmt 88 88 88 88 88 88 88 88 T.sub.2 ( C.) <1300 1304 <1350 <1350 <1350 <1350 <1350 1280 T.sub.3 ( C.) <1200 1170 <1200 <1200 <1200 <1200 <1200 1144 T.sub.4 ( C.) <1100 1079 <1100 <1100 <1100 <1100 <1100 1054 Sulfuric acid resistance (amount of weight loss (mg/cm.sup.2)) 0.05 0.003 0.003 0.004 0.008 0.007 0.007 0.007 Sulfuric acid resistance (transmission ability) Sulfuric acid resistance parameter S 4.88 9.46 9.46 8.99 7.86 7.58 7.58 7.58 Acid resistance parameter T 0.68 1.20 1.20 1.14 1.06 1.04 1.04 1.03 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00115 TABLE 115 Example Example Example Example Example Example Example Example (mol %) 802 803 804 805 806 807 808 809 SiO.sub.2 50 49.5 49.5 50 50 50 50 50 Al.sub.2O.sub.3 7.8 8 8 8 8 8 8 8.5 B.sub.2O.sub.3 5.2 6 6 5.5 5.5 6 6 5.5 MgO 20.5 20 20 20 20 19.5 19.5 20 CaO 4.5 3.5 3 3.5 3 3.5 3 3 SrO 3.2 4 4.5 4 4.5 4 4.5 4 BaO 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 1 TiO.sub.2 4.7 5 5 5 5 5 5 5 Y.sub.2O.sub.3 2.6 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 10.4 10.5 10.5 10.5 10.5 10.5 10.5 11.0 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + 2.6 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + 0.42 0.42 0.42 0.42 0.42 0.42 0.42 0.42 Al.sub.2O.sub.3 + RO) (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.34 0.34 0.34 0.34 0.34 0.33 0.33 0.34 MgO/RO 0.71 0.71 0.71 0.71 0.71 0.71 0.71 0.73 N 10 10 10 10 10 10 10 10 Young's modulus E (GPa) 102 101 101 101 101 100 100 101 Coefficient of thermal expansion (ppm/ C.) 5.24 5.19 5.20 5.18 5.18 5.14 5.14 5.10 Liquidus temperature TL ( C.) 1165 <1200 <1200 <1200 <1200 <1200 <1200 <1200 Young's modulus parameter Y 1.00 0.99 1.00 1.00 1.00 0.99 0.99 1.00 Liquidus parameter L 9.8 9.8 9.7 9.8 9.8 9.8 9.7 9.9 Thermal expansion parameter C 1.05 1.04 1.05 1.04 1.05 1.04 1.04 1.03 Glass transition point ( C.) Density (g/cm.sup.3) 2.92 2.91 2.91 2.91 2.92 2.90 2.91 2.90 Liquidus viscosity log .sub.L(dPa .Math. s) 2.5< 2.5< 2.5< 2.5< 2.5< 2.5< 2.5< 2.5< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 0< 0< 0< 0< 0< 0< 0< 0< Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 88 Transmittance (%) @1064 nm, 0.7 mmt 88 88 88 88 88 88 88 88 T.sub.2 ( C.) <1350 <1300 <1300 <1300 <1300 <1300 <1300 <1300 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 <1100 Sulfuric acid resistance (amount of weight 0.008 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 loss (mg/cm.sup.2)) Sulfuric acid resistance (transmission ability) Sulfuric acid resistance parameter S 7.36 Acid resistance parameter T 1.00 Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00116 TABLE 116 Example Example Example Example Example Example Example Example (mol %) 810 811 812 813 814 815 816 817 SiO.sub.2 50 50 50 50 50 50 50 50 Al.sub.2O.sub.3 8 8 8 8 8 8 8 8 B.sub.2O.sub.3 5.8 5.8 5.9 5.9 6 6 6 6 MgO 20 18.2 20 20 19.8 19.9 19.6 19.5 CaO 3 4 3.5 3 3.2 3.1 4.1 4.2 SrO 4 4 4 4.5 4.2 4.3 4.2 4 BaO 0.5 0.5 0.5 0.5 0.3 0.2 Li.sub.2O Na.sub.2O K.sub.2O ZnO P.sub.2O.sub.5 ZrO.sub.2 1 1 1 1 1 1 1 1 TiO.sub.2 5 5 5 5 5 5 5 5 Y.sub.2O.sub.3 2.7 2.5 2.1 2.1 2.5 2.5 2.1 2.3 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 10.7 10.5 10.1 10.1 10.5 10.5 10.1 10.3 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + 2.7 2.5 2.1 2.1 2.5 2.5 2.1 2.3 Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + 0.42 0.40 0.42 0.42 0.42 0.42 0.42 0.42 Al.sub.2O.sub.3 + RO) (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.33 0.32 0.33 0.33 0.33 0.33 0.33 0.33 MgO/RO 0.73 0.68 0.71 0.71 0.72 0.72 0.70 0.70 N 10 10 10 10 9 9 9 9 Young's modulus E (GPa) 101 99 100 100 100 101 100 100 Coefficient of thermal expansion (ppm/ C.) 5.14 5.10 5.10 5.11 5.11 5.10 5.11 5.12 Liquidus temperature TL ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 <1200 Young's modulus parameter Y 1.00 0.98 0.99 0.99 0.99 1.00 0.99 0.99 Liquidus parameter L 9.8 9.9 9.8 9.7 9.7 9.7 9.7 9.7 Thermal expansion parameter C 1.04 1.03 1.03 1.04 1.03 1.03 1.04 1.04 Glass transition point ( C.) Density (g/cm.sup.3) 2.91 2.90 2.88 2.89 2.90 2.89 2.87 2.88 Liquidus viscosity log .sub.L(dPa .Math. s) 2.5< 2.5< 2.5< 2.5< 2.5< 2.5< 2.5< 2.5< K.sub.IC (MPa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 0< 0< 0< 0< 0< 0< 0< 0< Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 88 88 88 88 Transmittance (%) @1064 nm, 0.7 mmt 88 88 88 88 88 88 88 88 T.sub.2 ( C.) <1300 <1310 <1300 <1300 <1300 <1300 <1300 <1300 T.sub.3 ( C.) <1200 <1200 <1200 <1200 <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 <1100 <1100 <1100 <1100 Sulfuric acid resistance (amount of weight <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 loss (mg/cm.sup.2)) Sulfuric acid resistance (transmission ability) Sulfuric acid resistance parameter S Acid resistance parameter T Deflection determination Manufacturability determination Transmission ability determination

TABLE-US-00117 TABLE 117 Example Example Example Example (mol %) 818 819 820 821 SiO.sub.2 52.1 52.1 52.3 52.3 Al.sub.2O.sub.3 7.7 7.7 7.7 7.7 B.sub.2O.sub.3 3.8 3.8 3.8 3.8 MgO 19.6 19.6 19.6 19.6 CaO 3.4 2.9 3.8 2.9 SrO 3.8 4.3 3.8 4.7 BaO Li.sub.2O Na.sub.2O K O ZnO P.sub.2O ZrO.sub.2 1 1 1 1 TiO.sub.2 4.8 4.8 5 5 Y.sub.2O.sub.3 3.8 3.8 3 3 Gd.sub.2O.sub.3 La.sub.2O.sub.3 WO.sub.3 Ta.sub.2O.sub.5 Al.sub.2O.sub.3 + rare earth oxide 11.5 11.5 10.7 10.7 Y.sub.2O.sub.3 + Gd.sub.2O.sub.3 + La.sub.2O.sub.3 + Nd.sub.2O.sub.3 + Ta.sub.2O.sub.5 + Nb.sub.2O.sub.5 3.8 3.8 3.0 3.0 Parameter A = (Al.sub.2O.sub.3 + RO)/(SiO.sub.2 + Al.sub.2O.sub.3 + RO) 0.40 0.40 0.40 0.40 (Al.sub.2O.sub.3 + MgO)/(SiO.sub.2 + Al.sub.2O.sub.3 + B.sub.2O.sub.3 + MgO) 0.33 0.33 0.33 0.33 MgO/RO 0.73 0.73 0.72 0.72 N 9 9 9 9 Young's modulus E (GPa) 104 104 102 102 Coefficient of thermal expansion (ppm/ C.) 5.18 5.19 5.10 6.11 Liquidus temperature TL ( C.) <1200 <1200 <1200 <1200 Young's modulus parameter Y 1.03 1.03 1.02 1.02 Liquidus parameter L 9.9 9.9 10.0 9.9 Thermal expansion parameter C. 1.04 1.05 1.03 1.04 Glass transition point ( C.) Density (g/cm ) 2.96 2.96 2.92 2.93 Liquidus viscosity log .sub.L (dPa .Math. s) 2.5< 2.5< 2.5< 2.5< K.sub.IC (Mpa .Math. m.sup.0.5) 0.8< 0.8< 0.8< 0.8< Transmittance (%) @308 nm, 0.7 mmt 0< 0< 0< 0< Transmittance (%) @350 nm, 0.7 mmt 75 75 75 75 Transmittance (%) @550 nm, 0.7 mmt 88 88 88 88 Transmittance (%) @1064 nm, 0.7 mmt 88 88 88 88 T.sub.2 ( C.) <1300 <1300 <1320 <1320 T.sub.3 ( C.) <1200 <1200 <1200 <1200 T.sub.4 ( C.) <1100 <1100 <1100 <1100 Sulfuric acid resistance (amount of weight loss (mg/cm.sup.2)) <0.010 <0.010 <0.010 <0.010 Sulfuric acid resistance (transmission ability) Sulfuric acid resistance parameter S Acid resistance parameter T Deflection determination Manufacturability determination Transmission ability determination indicates data missing or illegible when filed

Example 1

[0127] In Example 1, a glass having the composition shown in Table 1 was produced. In Example 1, a base plate having a diameter of 320 mm and a thickness of 6 mm was manufactured using a melt casting method. Next, a plurality of plates having a diameter of 300 mm and a thickness of 3 mm were cut out from the center of the base plate. Both surfaces of these plates were polished using cerium oxide as a polishing material to obtain a glass having a thickness of 0.7 mm.

[0128] For the glass of Example 1, the Young's modulus E (GPa) was measured. The Young's modulus was measured by an ultrasonic pulse method defined in JIS R 1602:1995 Testing methods for elastic modulus of fine ceramics. The bulk density of the sample was measured by the Archimedes method, the longitudinal wave velocity and the transverse wave velocity were measured using an ultrasonic thickness gage 38DL PLUS manufactured by Olympus Corporation, and the value of Young's modulus was determined.

[0129] For the glass of Example 1, the coefficient of linear thermal expansion (ppm/ C.) was measured. Measurement was performed in the range of 30 C. to 300 C. using a dilatometer (DIL 402 Expedis Supreme) manufactured by NETZSCH as a measuring apparatus, and an average coefficient of thermal expansion in the range of 50 C. to 200 C. was defined as the coefficient of linear thermal expansion .

[0130] For the glass of Example 1, the liquidus temperature T.sub.L ( C.) was measured. The liquidus temperature T.sub.L was measured by placing glass particles, which passed through a sieve with a mesh width of 4.0 mm and did not pass through a sieve with a mesh width of 2.3 mm, on a platinum dish, then holding the glass particles for 1 hour in an electric furnace set at a predetermined temperature, and measuring the temperature at which crystals were precipitated.

[0131] For the glass of Example 1, the melting temperature T.sub.2 ( C.), the working temperature T.sub.3 ( C.), and the molding temperature T.sub.4 ( C.) were measured as high temperature viscosity values. The melting temperature T.sub.2, the working temperature T.sub.3, and the molding temperature T.sub.4 were measured by an inner cylinder rotation method. For the glass of Example 1, the Young's modulus parameter Y was calculated using Formula (3).

[0132] For the glass of Example 1, the thermal expansion parameter C was calculated using Formula (2).

[0133] For the glass of Example 1, the liquidus parameter L was calculated using Formula (3).

[0134] For the glass of Example 1, the glass transition temperature ( C.) was measured. The glass transition temperature was measured by obtaining an expansion curve until the glass was softened using a thermal expansion measuring apparatus.

[0135] For the glass of Example 1, the density (g/cm.sup.3) was measured. The density was measured by the Archimedes method.

[0136] For the glass of Example 1, the liquidus viscosity was measured. The liquidus viscosity was measured by measuring a temperature-viscosity curve according to an inner cylinder rotation method and calculating the viscosity at the liquidus temperature.

[0137] For the glass of Example 1, the fracture toughness value K.sub.IC (MPa.Math.m.sup.0.5) was measured. The fracture toughness value K.sub.IC was measured using a single-edge-precracked-beam method (SEPB method) as defined in JIS R1607:2015 Testing methods for fracture toughness of fine ceramics at room temperature.

[0138] For the glass of Example 1, the transmittance for light with a wavelength of 308 nm, the transmittance for light with a wavelength of 350 nm, the transmittance for light with a wavelength of 550 nm, and the transmittance for light with a wavelength of 1064 nm were measured. The transmittance was measured by measuring a spectral transmittance curve using an ultraviolet-visible spectrophotometer (UH4150 type, manufactured by Hitachi High-Tech Corporation).

[0139] For the glass of Example 1, the weight (mg) before the acid immersion test and the weight (mg) after the acid immersion test were measured, and the amount of weight loss (amount of weight change) was calculated by the method described in the above embodiment. As the acid immersion test, the glass was immersed in sulfuric acid (H.sub.2SO.sub.4) having a pH of 2 and a temperature of 40 C. for 2 hours. The weight of the states before and after the acid immersion test was accurately measured using an electronic balance.

[0140] For the glass of Example 1, the sulfuric acid resistance parameter S was calculated using Formula (4).

[0141] For the glass of Example 1, the acid resistance parameter T was calculated using Formula (5).

[0142] The measurement results and the calculation results are shown in Table 1.

Examples 2 to 821

[0143] In Examples 2 to 821, a glass was manufactured in the same manner as in Example 1 except that each composition of the glass was as shown in Table 1. The measurement results and calculation results of each example are shown in Tables 1 to 117.

Evaluation

[0144] For the glass of each example, deflection and manufacturability were determined. The deflection evaluation was carried out on the basis of the Bi-Metal warpage calculation defined in the document S. Timoshenko, Analysis of Bi-Metal Thermostats J. Opt. Soc. Am. 11 (1925) 233. FIG. 2 is a schematic diagram for explaining the deflection evaluation. Here, as illustrated in FIG. 2, the amount of warpage is defined as an amount of displacement of the end portion of the glass 10 in either of the vertical up direction or the vertical down direction with the center of the second surface 14 as a height reference, in a process of molding and bonding a semiconductor substrate with a resin to the first surface 12 side of the glass 10 processed into the shape of FIG. 1, the displacement being caused when cooling from a high temperature state of 200 C. to a low temperature of 20 C. is performed. Specifically, the amount of warpage is calculated by Formula (4).

[00007]$\begin{array}{cc}=\frac{6L^2\left({}_2-{}_1\right)\left(T_2-T_1\right){\left(1+m\right)}^2}{8h\left[3{\left(1+m\right)}^2+\left(1-\mathrm{mn}\right)\left\{m^2+{\left(\mathrm{mn}\right)}^{-1}\right\}\right]}& \left(1\right)\end{array}$

[0145] Here, as illustrated in FIG. 2, L is a length in a warpage direction (lateral direction in FIG. 2) of the glass 10, .sub.1 is a coefficient of linear thermal expansion of the resin substrate 20, .sub.2 is a coefficient of linear thermal expansion of the glass 10, T.sub.2 is a temperature after cooling (here, 20 C.), and T.sub.1 is a temperature before cooling (here, 200 C.). In addition, m is a.sub.1/a.sub.2, h is a.sub.1+a.sub.2, and n is E.sub.1/E.sub.2. Here, a.sub.1 is the thickness of the resin substrate 20, a.sub.2 is the thickness of the glass 10, E.sub.1 is the Young's modulus of the resin substrate 20, and E.sub.2 is the Young's modulus of the glass 10. In the deflection evaluation, the thickness of the resin substrate 20 to be bonded to the glass 10 was assumed to be 0.3 mm and the Young's modulus thereof was assumed to be 31.5 GPa, in consideration of semiconductor mounting. Since application to various manufacturing processes was anticipated, assuming two patterns: {coefficient of linear thermal expansion of glass (ppm/ C.)}+0.5 ppm/ C. and {coefficient of linear thermal expansion of glass (ppm/ C.)}0.5 ppm/ C., for the coefficient of linear thermal expansion, each amount of warpage was calculated in a case where the thickness of the glass 10 was 0.7 mm and length L=300 mm. In the determination of deflection, a case where the total value of the absolute values of the respective calculated values was 1.732 mm or less was evaluated as , and a case where the total value was higher than 1.732 mm was evaluated as . The manufacturability refers to ease of manufacturing, and a case where the liquidus temperature was less than 1300 C. and the melting temperature was less than 1400 C. was evaluated as , and a case where at least one of a liquidus temperature of 1300 C. or higher or a melting temperature of 1400 C. or higher was satisfied was evaluated as . In the evaluation of the transmission ability, a case where the glass 10 having a thickness D of 0.7 mm had an internal transmittance for light with a wavelength of 350 nm of 70% or more, an internal transmittance for light with a wavelength of 550 nm of 85% or more, and an internal transmittance for light with a wavelength of 1064 nm of 80% or more was evaluated as and a case where the glass had an internal transmittance for light with a wavelength of 350 nm of less than 70%, an internal transmittance for light with a wavelength of 550 nm of less than 85%, or an internal transmittance for light with a wavelength of 1064 nm of less than 80% was evaluated as

[0146] As shown in Tables 1 to 117, in Examples 1 to 759 and 770 to 821 in which the content of SiO.sub.2 is 40% to 60%, the content of B.sub.2O.sub.3 is 0.01% to 15%, the total content of Al.sub.2O.sub.3 and the rare earth oxide is 0% to 20%, and the parameter A is 0.38 or more, the deflection determination, the manufacturability determination, and the transmission ability determination are , and it can be seen that it is possible to easily manufacture while suppressing deflection and to increase the transmission ability. On the other hand, in Examples 760 to 769, which are comparative examples, at least one of the manufacturability determination, the deflection determination, or the transmission ability is , and it can be seen that it cannot be easily manufactured or it is not suitable as a substrate.

[0147] In addition, for some examples, the sulfuric acid resistance (transmission ability) was confirmed as an optional evaluation. It is preferable that there is no change in the transmission ability when the method for determining a change in the transmission ability after exposure to acid described in the above-described embodiment is used as an evaluation method. In the determination of a change in the transmission ability after exposure to acid, at the time of visual observation, a case where no cloudy portion was observed on the surface was evaluated as , and a case where a cloudy portion was observed was evaluated as .

[0148] According to the present invention, it is possible to facilitate manufacturing while suppressing deflection and to enhance the transmission ability.

[0149] Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.