Described is a process for the production of synthetic fused silica in which the feedstock vapor is reacted from an organosilicon starting compound and any combustible burner auxiliary gases at an air number in the burner of less than or equal to 1.00. Furthermore, one embodiment relates to a corresponding apparatus.

The present disclosure provides a method for modification of surface of an initial optical fiber preform. The initial optical fiber preform is manufactured using at least one preform manufacturing process. The surface of the initial optical fiber preform is treated with 50-70 liters of chlorine per square meter of the surface of the initial optical fiber preform. The surface of the initial optical fiber preform is flame polished using a flame polishing module. The treatment of the surface of the initial optical fiber preform with chlorine and flame polishing of the surface of the initial optical fiber preform collectively converts the initial optical fiber preform into a modified optical fiber preform.

When organic siloxane in a liquid state is used as a raw material for glass particles, the formation of polymerized substances is suppressed when the raw material is vaporized in a vaporizer. In the manufacturing method of porous glass base material according to the present invention, the liquid organic siloxane, which is the raw material, is mixed with a carrier gas in the vaporizer, vaporized by the heat generated from the inner wall of the vaporizer heated by a heater unit, and supplied to the burner as a gas raw material. The porous glass base material is manufactured by depositing the glass particles generated by the combustion of the gas raw material on the starting material. The heating output of the heater unit is controlled so that the maximum temperature of the inner wall of the vaporizer is 230° C. or lower.

A manufacturing apparatus of porous glass base material includes deposition apparatuses that manufacture a porous glass base material by generating raw material particles from vaporized raw material compounds in an oxyhydrogen flame, and then depositing the generated raw material particles on a rotating starting material. The manufacturing apparatus includes a storage container that stores liquid raw material compounds for each compound, a vapor generation mechanism that vaporizes the raw material compounds, and a gas channel that supplies the vaporized raw material compounds to the deposition apparatuses. The gas channel includes a common gas channel shared to supply vaporized raw material compounds to the plurality of deposition apparatuses, and individual gas channels branched off from the common gas channel to supply vaporized raw material compounds to each of the deposition apparatuses individually. Each of the individual gas channels has a flow controller, a steam valve, and a valve.

An apparatus for the continuous production of hollow quartz-glass ingots, comprising a) a crucible or refractory tank for providing a softened quartz-glass mass having a dieorifice in the bottom of the crucible or refractory tank; b) a mandrel vertically drawing off the softened quartz-glass mass through a die toprovide a hollow quartz-glass ingot; and c) a cutting section for on-line cutting of the hollow quartz-glass ingot to a specificlength, characterized in that the apparatus comprises active means for cooling the internalsurface of the hollow quartz-glass ingot prior to the cutting station.

The present invention relates to a continuous method for the production of hollow quartz-glass ingots and an apparatus for said method, whereby the hollow quartz-glass ingots are cooled on the internal surface.

A process for producing a glass body, the process including flowing oxygen gas from a burner in a furnace at a flow rate of greater than 12.0 standard liters per minute and flowing a precursor gas mixture from the burner. The process further including oxidizing the precursor gas mixture with the oxygen gas to form glass particles and depositing the glass particles on a collection cup to form the glass body.

A diffuser material of synthetically produced, pore-containing quartz glass and a method for the manufacture of a molded body consisting fully or in part thereof. The diffuser material has a chemical purity of at least 99.9% SiO.sub.2, a cristobalite content of not more than 1%, and a density in the range of 2.0 to 2.18 g/cm.sup.3. Starting therefrom, to indicate a diffuser material which is improved with respect to diffuse reflectivity with Lambertian behavior over a wide wavelength range, high material homogeneity and UV radiation resistance, the quartz glass has a hydroxyl group content in the range of at least 200 wt. ppm and at least 80% of the pores have a maximum pore dimension of less than 20 μm.

A diffuser material of synthetically produced, pore-containing quartz glass and a method for the manufacture of a molded body consisting fully or in part thereof. The diffuser material has a chemical purity of at least 99.9% SiO.sub.2, a cristobalite content of not more than 1%, and a density in the range of 2.0 to 2.18 g/cm.sup.3. Starting therefrom, to indicate a diffuser material which is improved with respect to diffuse reflectivity with Lambertian behavior over a wide wavelength range, high material homogeneity and UV radiation resistance, the quartz glass has a hydroxyl group content in the range of at least 200 wt. ppm and at least 80% of the pores have a maximum pore dimension of less than 20 μm.

A method includes impregnating a region of a glass sheet with a filler material in a liquid state. The glass sheet includes a plurality of glass soot particles. The filler material is solidified subsequent to the impregnating step to form a glass/filler composite region of the glass sheet.