A method for the production of synthetic quartz glass using a special cleaning device is provided. The method includes (a) evaporating a production material containing a polymerizable polyalkylsiloxane compound while forming a production material vapor, (b) passing the production material vapor resulting from step (a) through a cleaning device to purify the production material vapor, (c) supplying the purified production material vapor resulting from step (b) to a reaction zone in which the purified production material vapor is converted to SiO.sub.2 particles through oxidation and/or through hydrolysis, (d) depositing the SiO.sub.2 particles resulting from step (c) on a deposition surface, and optionally drying and vitrifying the deposited SiO.sub.2 particles resulting from step (d) to form synthetic quartz glass. The cleaning device includes a bulk of porous silica particles which have a BET specific surface area of at least 2 m.sup.2/g. A device for carrying out the method is also provided.

A method for manufacturing an SiO.sub.2—TiO.sub.2 based glass upon a target by a direct method, includes a first process of preheating the target and a second process of growing an SiO.sub.2—TiO.sub.2 based glass ingot to a predetermined length upon the target which has been preheated, wherein the target is heated in the first process such that, in the second process, the temperature of growing surface of the glass ingot is maintained at or above a predetermined lower limit temperature.

A method for producing titanium-doped synthetic quartz glass includes: (A) providing a liquid SiO.sub.2 feedstock material that comprises more than 60% by weight of the polyalkylsiloxane D4; (B) evaporating the liquid SiO.sub.2 feedstock material to produce a gaseous SiO.sub.2 feedstock vapor; (C) evaporating a liquid TiO2 feedstock material to produce a gaseous TiO2 feedstock vapor; (D) converting the SiO.sub.2 feedstock vapor and the TiO2 feedstock vapor into SiO2 particles and TiO2 particles, respectively; (E) depositing the SiO2 particles and the TiO2 particles on a deposition surface while forming a titanium-doped SiO.sub.2 soot body; (F) vitrifying the titanium-doped SiO.sub.2 soot body while forming the synthetic quartz glass, whereby the TiO2 concentration of the synthetic quartz glass is between 5% by weight and 11% by weight. The liquid SiO.sub.2 feedstock material comprises at least one additional component made of the polyalkylsiloxane D3 having a weight fraction of mD3 and one additional component made of the polyalkylsiloxane D5 having a weight fraction of mD5 at a weight ratio of mD3/mD5 in a range of 0.01 to 1, and the liquid SiO.sub.2 feedstock material provided is evaporated while maintaining the weight ratio of mD3/mD5 and at least 99% by weight thereof are evaporated to form the gaseous SiO.sub.2 feedstock vapor.

One aspect relates to a method for the production of synthetic quartz glass. Moreover, one aspect relates to a polyalkylsiloxane compound, which includes certain specifications with respect to chlorine content, metallic impurities content, and residual moisture, as well as the use thereof for the production of synthetic quartz glass. One aspect also relates to a synthetic quartz glass that can be obtained according to the method of one embodiment.

A method for producing rod lenses with an enveloping diameter of the rod lens face of up to 200 mm and an edge length of at least 800 mm. The method is characterized in that fabrication is performed from a cylindrical rod lens element made from synthetic quartz glass material configured as a fused silica ingot. This is performed using a flame hydrolysis method with a direct one stage deposition process of SIO.sub.x particles from a flame stream onto die that rotates and is moveable in a linear manner with respect to the flame stream.

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.

This raw material supply device supplies a raw material for producing glass fine particle deposits, to a burner and includes a raw material tank; a liquid raw material pipe having one end thereof connected to the raw material tank; a liquid raw material pressure feed pump that pumps siloxane, being a liquid raw material, from the raw material tank via the liquid raw material pipe; a pressure adjustment valve provided on a secondary side of the liquid raw material pressure feed pump in the liquid raw material pipe; an MFC for liquid, connected to the other end of the liquid raw material pipe; and an aeration device that is connected to the secondary side of the MFC for liquid and aerates the liquid raw material. The pipe on the secondary side of the pressure adjustment valve is connected to a location having lower pressure than the primary side pressure.

A method for the production of synthetic quartz glass using a special cleaning device is provided. The method includes (a) evaporating a production material containing a polymerizable polyalkylsiloxane compound while forming a production material vapor, (b) passing the production material vapor resulting from step (a) through a cleaning device to purify the production material vapor, (c) supplying the purified production material vapor resulting from step (b) to a reaction zone in which the purified production material vapor is converted to SiO.sub.2 particles through oxidation and/or through hydrolysis, (d) depositing the SiO.sub.2 particles resulting from step (c) on a deposition surface, and optionally drying and vitrifying the deposited SiO.sub.2 particles resulting from step (d) to form synthetic quartz glass. The cleaning device includes a bulk of porous silica particles which have a BET specific surface area of at least 2 m.sup.2/g. A device for carrying out the method is also provided.

A method for manufacturing a glass ingot includes preparing a supply system including a gasifier that gasifies a raw material compound and a burner that combusts the gasified raw material compound; adding an oxygen-containing gas to the raw material compound at a plurality of addition places including an upstream addition place located in the gasifier or on an upstream side of the gasifier and a downstream addition place located on a downstream side of the gasifier in which locations of the raw material compound in a flow direction are different in the supply system so as to form a raw material mixture; and adding the oxygen-containing gas at the upstream addition place so that a concentration of oxygen or a concentration of the raw material compound in the raw material mixture is not in a combustible range of the raw material mixture.