A low infrared absorbing lithium glass includes FeO in the range of 0.0005-0.015 wt %, more preferably 0.001-0.010 wt %, and a redox ratio in the range of 0.005-0.15, more preferably in the range of 0.005-010. The glass can be chemically tempered and used to provide a ballistic viewing cover for night vision goggles or scope. A method is provided to change a glass making process from making a high infrared absorbing lithium glass having FeO in the range of 0.02 to 0.04 wt % and a redox ratio in the range of 0.2 to 0.4 to the low infrared absorbing lithium glass by adding additional oxidizers to the batch materials. A second method is provided to change a glass making process from making a low infrared absorbing lithium glass to the high infrared absorbing lithium glass by adding additional reducers to the batch material. In one embodiment of the invention the oxidizer is CeO.sub.2. An embodiment of the invention covers a glass made according to the method.

The present invention provides a glass substrate in which in a heat treatment step of sticking a silicon substrate and a glass substrate to each other, an alkali ion is hardly diffused into the silicon substrate, and a residual strain generated in the silicon substrate is small. A glass substrate of the present invention has: an average thermal expansion coefficient .sub.50/100 at 50 C. to 100 C. of 2.70 ppm/ C. to 3.20 ppm/ C.; an average thermal expansion coefficient .sub.200/300 at 200 C. to 300 C. of 3.45 ppm/ C. to 3.95 ppm/ C.; a value .sub.200/300/.sub.50/100 obtained by dividing the average thermal expansion coefficient .sub.200/300 at 200 C. to 300 C. by the average thermal expansion coefficient .sub.50/100 at 50 C. to 100 C. of 1.20 to 1.30; and a content of an alkali metal oxide being 0% to 0.1% as expressed in terms of a molar percentage based on oxides.

There is provide an optical filter suppressed in incidence angle dependence and having high visible light transmittance. The optical filter includes: an absorption layer containing a first near-infrared absorbent (DA) having a maximum absorption wavelength (DA_T.sub.min) in wavelengths of 685 to 715 nm and a second near-infrared absorbent (DB) having a maximum absorption wavelength (DB_T.sub.min) in wavelengths of 705 to 725 nm or wavelengths of more than 725 nm and 900 nm or less on a side of a wavelength longer than the maximum absorption wavelength (DA_T.sub.min), and satisfying specific light absorption characteristics; and a reflection layer including a dielectric multilayer film satisfying specific reflection characteristics in wavelengths of 700 to 1150 nm, wherein a transmittance of the reflection layer in a boundary region of visible light and near-infrared light and a transmittance of the absorption layer have a specific relation.

A glass-ceramic, includes a silicate-containing glass comprising a first portion and a second portion. A plurality of crystalline precipitates comprising at least one of W and Mo. The crystalline precipitates are distributed within at least one of the first and second portions of the silicate-containing glass. The glass-ceramic comprises a difference in absorbance between the first and second portions of 0.04 optical density (OD)/mm or greater over a wavelength range of from 400 nm to 1500 nm.

The invention relates to a filter glass comprising Na.sub.2O and K.sub.2O and the following (in % by weight on an oxide basis): TABLE-US-00001 P.sub.2O.sub.5 58-68 Al.sub.2O.sub.3 5-10 CuO 8-15 V.sub.2O.sub.5 0.05-1 SiO.sub.2 <2 F <1 Total RO (R = Mg, Ca, Sr, Ba) 0-11 Total R.sub.2O (R = Li, Na, K) 3-17.

A light selective transmission type glass 10 according to the present invention includes: a glass substrate 12; and a light selective transmission layer 11 provided on at least one main surface of the glass substrate 12. The glass substrate 12 has an average thermal expansion coefficient .sub.50/100 at 50 C. to 100 C. of 2.70 ppm/ C. to 3.20 ppm/ C., an average thermal expansion coefficient .sub.200/300 at 200 C. to 300 C. of 3.45 ppm/ C. to 3.95 ppm/ C., a value .sub.200/300/.sub.50/100 obtained by dividing the average thermal expansion coefficient .sub.200/300 at 200 C. to 300 C. by the average thermal expansion coefficient .sub.50/100 at 50 C. to 100 C. of 1.20 to 1.30, and a content of an alkali metal oxide being 0% to 0.1%.

The present invention refers to a glass composition and a method for the commercial production of a solar control thin green glass mainly for use in the automotive industry such as symmetric-hybrid windshields or asymmetric-hybrid windshields, sidelights and rear windows, which includes a basic composition of soda-lime-silica glass, and consists essentially, in weight percentage: from 1.30 to 2.50% of total iron expressed as Fe.sub.2O.sub.3; from 15 to 40% of Fe.sup.2+ (Ferrous) and from 0.15 to 0.65% of FeO, expressed as Fe.sub.2O.sub.3; from about 0.05 to about 0.30% of SO.sub.3; from about 0.02 to about 1.0% of TiO.sub.2; from about 0.0002 to about 0.03% of Cr.sub.2O.sub.3; and from about 0.0002 to about 0.015% of CuO. The solar control thin green glass having an illuminant A light transmission (T.sub.LA) greater than 70%, a direct solar transmittance (T.sub.DS) of less than 51%, a total UV light transmittance (T.sub.UV) of less than 40% and a total solar transmittance (T.sub.TS) of less than 63%; a dominant wavelength () from 490 nm to 600; and excitation purity less than 7, for thickness from about 0.7 to 3.0 mm.

The present invention aims to provide a heat-ray- and ultraviolet-absorbing glass plate having low solar transmittance and ultraviolet transmittance, having a high visible light transmittance, and containing a small amount of bubbles. The present invention relates to a heat-ray- and ultraviolet-absorbing glass plate that is a soda lime glass having a specific composition, having a mass proportion of divalent iron to the total iron being 50% or more, and having, as a value calculated as 4 mm thickness of the glass plate, a visible light transmittance Tv of 66% or more, a solar transmittance Te of 65% or less, a ratio Tv/Te of Tv and Te of 1.3 or more, and an ultraviolet transmittance Tuv of 50% or less.

A low infrared absorbing lithium glass includes FeO in the range of 0.0005-0.015 wt %, more preferably 0.001-0.010 wt %, and a redox ratio in the range of 0.005-0.15, more preferably in the range of 0.005-010. The glass can be chemically tempered and used to provide a ballistic viewing cover for night vision goggles or scope. A method is provided to change a glass making process from making a high infrared absorbing lithium glass having FeO in the range of 0.02 to 0.04 wt % and a redox ratio in the range of 0.2 to 0.4 to the low infrared absorbing lithium glass by adding additional oxidizers to the batch materials. A second method is provided to change a glass making process from making a low infrared absorbing lithium glass to the high infrared absorbing lithium glass by adding additional reducers to the batch material. In one embodiment of the invention the oxidizer is CeO.sub.2. An embodiment of the invention covers a glass made according to the method.

A product is provided that includes a volume-colored monolithic glass or glass ceramic element and to a method for producing same. The glass or glass ceramic element has a first region in which the coloration is modified so that light transmission of the first region differs from light transmission of a second, adjacent region. The light scattering in the region of modified coloration in the glass or glass ceramic remains the same as light scattering in the second, adjacent region with non-modified light transmission.