In known methods for producing a glass component, a void-containing intermediate product containing doped or non-doped SiO.sub.2 is inserted into a sheath tube composed of glass, which has a longitudinal axis and an inner bore, and is thermally treated therein. In order to subject the intermediate product to a thermal and/or reactive treatment that is reproducible and uniform in its effect from this starting point, it is proposed in one embodiment that into the sheath tube's inner bore a first gas-permeable gas diffuser is inserted which is displaceable along the sheath tube's longitudinal axis and is pressed against the intermediate product during the thermal treatment.

One aspect is a method for producing a hollow porous quartz glass base material, and a method for producing a synthetic quartz glass cylinder, wherein even when the hollow porous quartz glass base material (soot body) is produced in large weight and high bulk density, the ease of target extraction is maintained and target extraction is performed stably, and a large weight soot body can be produced. The method for producing a hollow porous quartz glass base material comprises: preparing a heat resistant substrate, which has a columnar or cylindrical shape and has an outer surface on which SiO.sub.2 particles are deposited, the outer surface having a surface roughness in which the maximum height Rz is less than 9 m and the arithmetic average roughness Ra is less than 1 m; rotating the heat resistant substrate and depositing SiO.sub.2 particles on the outer surface of the heat resistant substrate to form a glass particulate deposit; and extracting the heat resistant substrate from the glass particulate deposit to produce a hollow porous quartz glass base material.

An optical fiber with low fictive temperature along with a system and method for making the optical fiber are provided. The system includes a reheating stage that heats the fiber along the process pathway to a temperature sufficient to lower the fictive temperature of the fiber by relaxing the glass structure and/or driving the glass toward a more nearly equilibrium state. The fiber is drawn from a preform, conveyed along a process pathway, cooled and subsequently reheated to increase the time of exposure of the fiber to temperatures conducive to lowering the fictive temperature of the fiber. The process pathway may include multiple reheating stages as well as one or more fiber-turning devices.

There is provided a method of processing an oxygen-containing workpiece. The method of processing an oxygen-containing workpiece includes controlling a fluorine concentration in the oxygen-containing workpiece based on at least one of a kind of a fluorine-containing processing gas, a processing temperature and a processing pressure used for processing the oxygen-containing workpiece.

A Photonic Crystal Fiber (PCF) a method of its production and a supercontinuum light source comprising such PCF. The PCF has a longitudinal axis and includes a core extending along the length of said longitudinal axis and a cladding region surrounding the core. At least the cladding region includes a plurality of microstructures in the form of inclusions extending along the longitudinal axis of the PCF in at least a microstructured length section. In at least a degradation resistant length section of the microstructured length section the PCF includes hydrogen and/or deuterium. In at least the degradation resistant length section the PCF further includes a main coating surrounding the cladding region, which main coating is hermetic for the hydrogen and/or deuterium at a temperature below T.sub.h, wherein T.sub.h is at least about 50 C., preferably 50 C.<T.sub.h<250 C.

A Photonic Crystal Fiber (PCF) a method of its production and a supercontinuum light source comprising such PCF. The PCF has a longitudinal axis and includes a core extending along the length of said longitudinal axis and a cladding region surrounding the core. At least the cladding region includes a plurality of microstructures in the form of inclusions extending along the longitudinal axis of the PCF in at least a microstructured length section. In at least a degradation resistant length section of the microstructured length section the PCF includes hydrogen and/or deuterium. In at least the degradation resistant length section the PCF further includes a main coating surrounding the cladding region, which main coating is hermetic for the hydrogen and/or deuterium at a temperature below T.sub.h, wherein T.sub.h is at least about 50? C., preferably 50? C.<T.sub.h<250? C.

A porous glass base material sintering method comprising measuring a feeding speed V.sub.f of a porous glass base material and a movement speed V.sub.w of a bottom end of the glass base material; performing a sintering treatment of the porous glass base material presetting, for each feeding distance L of the porous glass base material, a greater-than-1 target value .sub.S (L) of an elongation rate in a straight body portion of the porous glass base material calculated based on a ratio V.sub.w/V.sub.f, and controlling at least one of a temperature of the heating furnace and a feeding speed of the porous glass base material such that a measured value of the elongation rate of the porous glass base material matches with the target value .sub.S (L).

A quartz glass container is shown and described herein. The quartz glass container exhibits a low concentration of surface defects on an inner surface of the container. In aspects hereof, the container may have a surface defect density of 50 or fewer surface defects per square centimeter within a 1 cm band centered 1 cm from the base of the container.

A Photonic Crystal Fiber (PCF) a method of its production and a supercontinuum light source comprising such PCF. The PCF has a longitudinal axis and includes a core extending along the length of said longitudinal axis and a cladding region surrounding the core. At least the cladding region includes a plurality of microstructures in the form of inclusions extending along the longitudinal axis of the PCF in at least a microstructured length section. In at least a degradation resistant length section of the microstructured length section the PCF includes hydrogen and/or deuterium. In at least the degradation resistant length section the PCF further includes a main coating surrounding the cladding region, which main coating is hermetic for the hydrogen and/or deuterium at a temperature below T.sub.h, wherein T.sub.h is at least about 50? C., preferably 50? C.<T.sub.h<250? C.

A method for producing a solid body of glass is described. The method comprises providing a polymerisable composition, curing the polymerisable composition to obtain a cured body, subjecting the cured body to thermal debinding to substantially remove the organic components in the cured body, and subjecting the cured body to sintering to obtain a solid body of silica glass. The polymerisable composition one or more at least partially organic polymerisable compound(s) which form a liquid composition at operating temperature and a solid source of silica as colloidal silica particles or silica glass micro-/nanoparticles dispersed in the liquid composition. The one or more at least partially organic polymerisable compounds comprises at least one organosilicon compound as a second source of silica that is liquid or solubilisable in the liquid composition at operating temperature to thereby increase the silica loading of the cured body prior to sintering. Compositions and methods for producing solid glass objects by additive manufacturing are also described.