A process for producing a fluorinated quartz glass is described, including providing an SiO.sub.2 soot body; reacting the SiO.sub.2 soot body with a fluorinating agent having a boiling point of greater than or equal to −10° C. to obtain a fluorinated SiO.sub.2 soot body; and vitrifying the fluorinated SiO.sub.2 soot body.

A process for the production of a fluorinated quartz glass including the steps of generating SiO.sub.2 particles in a synthesis burner; depositing the resulting SiO.sub.2 particles into a body; and vitrifying the resulting body, wherein a fluorinating agent having a boiling point greater than or equal to −10° C. is supplied to the synthesis burner.

A method of manufacturing a quartz glass fibre includes producing a quartz glass primary preform by modified chemical vapor deposition (MCVD) in a quartz glass substrate tube and inserting the quartz glass primary preform into a glass jacketing tube. Defect-generating UV radiation is irridiated into the cross-sectional area of the glass jacketing tube while combining the quartz glass primary preform with the glass jacketing tube in the jacketing process to form a cladding layer to a secondary preform. A quartz glass fibre is pulled from the secondary preform.

The present invention relates to a method of manufacturing an optical fiber preform for obtaining an optical fiber with low transmission loss. A core preform included in the optical fiber preform comprises three or more core portions, which are each produced by a rod-in-collapse method, and in which both their alkali metal element concentration and chlorine concentration are independently controlled. In two or more manufacturing steps of the manufacturing steps for each of the three or more core portions, an alkali metal element is added. As a result, the mean alkali metal element concentration in the whole core preform is controlled to 7 atomic ppm or more and 70 atomic ppm or less.

Doped quartz glass components for use in a plasma-assisted manufacturing process contain at least one dopant which is capable of reacting with fluorine to form a fluoride compound, and the fluoride compound has a boiling point higher than that of SiF.sub.4. The doped quartz glass component has high dry-etch resistance and low particle formation, and has uniform etch removal when used in a plasma-assisted manufacturing process. The doped quartz glass has a microhomogeneity defined by (a) a surface roughness with an R.sub.a value of less than 20 nm after the surface has been subjected to a dry-etching procedure as specified in the description, or (b) a dopant distribution with a lateral concentration profile in which maxima of the dopant concentration are at an average distance apart of less than 30 μm.

The present disclosure relates to a glass composition as well as a glass powder. The disclosure also relates to the use in the dental field, e.g. as dental material such as dental filling or dental restauration material, in particular as or for the production of a glass ionomer cement, for example for the treatment and/or for the filling of cavities in human and/or animal teeth and/or for tooth restoration.

A resin composition for coating an optical fiber comprises: a base resin containing a photopolymerizable compound and a photopolymerization initiator; and hydrophobic inorganic oxide particles, wherein the photopolymerizable compound comprises urethane (meth)acrylate and aliphatic epoxy (meth)acrylate, and the content of the aliphatic epoxy (meth)acrylate is 1.0% by mass or more and 45% by mass or less based on the total amount of the photopolymerizable compound.

A glass substrate for EUVL includes a first main surface having a rectangular shape; a second main surface having a rectangular shape on an opposite side to the first main surface; four end surfaces orthogonal to the first and second main surfaces; four first chamfered surfaces formed on boundaries between the first main surface and the end surfaces; and four second chamfered surfaces formed on boundaries between the second main surface and the end surfaces. The glass substrate for EUVL is formed of quartz glass containing TiO.sub.2. The end surfaces include fluorine (F) and an element (A) other than fluorine that forms a gas cluster with fluorine, and satisfy relations:

S1=∫.sub.0.sup.x=50[nm]{D1(x)−(a1x+b1)}dx>0.2  (1)

S2=∫.sub.0.sup.x=50[nm]{D2(x)−(a2x+b2)}dx>0.03  (2)

An optical fiber includes a glass portion, a primary coating layer, and a secondary coating layer. In the optical fiber, a value of microbend loss characteristic factor F.sub.μBL_GO is 2.6 ([GPa.sup.−1.Math.μm.sup.−10.5.Math.dB/turn].Math.10.sup.−27) or less, when represented by

F.sub.μBL_GO=F.sub.μBL_G×F.sub.μBL_O

by using geometry microbend loss characteristic F.sub.μBL_G and optical microbend loss characteristic F.sub.μBL_O.

A method of forming an optical fiber, including: exposing a soot core preform to a dopant gas at a pressure of from 1.5 atm to 40 atm, the soot core preform comprising silica, the dopant gas comprising a first halogen doping precursor and a second halogen doping precursor, the first halogen doping precursor doping the soot core preform with a first halogen dopant and the second halogen precursor doping the soot core preform with a second halogen dopant; and sintering the soot core preform to form a halogen-doped closed-pore body, the halogen-doped closed-pore body having a combined concentration of the first halogen dopant and the second halogen dopant of at least 2.0 wt %.