摘要:
The present invention is directed to a purified polyalkylsiloxane composition having a boiling point, under atmospheric conditions, of less than about 250.degree. C. and containing high boiling impurities, including siloxanes and silanol-terminated siloxanes, that have boiling points, under atmospheric conditions, of greater than about 250.degree. C. in a total concentration of less than 14 ppm. The present invention is further directed to a method of producing a purified polyalkylsiloxane composition, having a boiling point, under atmospheric conditions, of less than about 250.degree. C., by distilling a polyalkylsiloxane starting material containing high boiling impurities having boiling points, under atmospheric conditions, of greater than about 250.degree. C. in a total concentration of at least 14 ppm, under conditions effective to produce a purified polyalkylsiloxane composition having a boiling point under atmospheric conditions of less than about 250.degree. C., and containing high boiling impurities, having boiling points, under atmospheric conditions, of greater than about 250.degree. C., in a total concentration of less than 14 ppm. In preferred embodiments, low boiling components (including silanols and preferably also hexamethylcyclotrisiloxane) are reduced to less than about 100 ppm. The present invention is further directed to a method of producing fused silica glass by conversion of the purified polyalkylsiloxane composition.
摘要:
The present invention is directed to a purified polyalkylsiloxane composition having a boiling point, under atmospheric conditions, of less than about 250.degree. C. and containing high boiling impurities, including siloxanes and silanol-terminated siloxanes, that have boiling points, under atmospheric conditions, of greater than about 250.degree. C. in a total concentration of less than 14 ppm. The present invention is further directed to a method of producing a purified polyalkylsiloxane composition, having a boiling point, under atmospheric conditions, of less than about 250.degree. C., by distilling a polyalkylsiloxane starting material containing high boiling impurities having boiling points, under atmospheric conditions, of greater than about 250.degree. C. in a total concentration of at least 14 ppm, under conditions effective to produce a purified polyalkylsiloxane composition having a boiling point under atmospheric conditions of less than about 250.degree. C., and containing high boiling impurities, having boiling points, under atmospheric conditions, of greater than about 250.degree. C., in a total concentration of less than 14 ppm. In preferred embodiments, low boiling components (including silanols and preferably also hexamethylcyclotrisiloxane) are reduced to less than about 100 ppm. The present invention is further directed to a method of producing fused silica glass by conversion of the purified polyalkylsiloxane composition.
摘要:
The present invention is directed to a method for making fused silica glass. A liquid, preferably halide-free, silicon-containing compound capable of being converted by thermal oxidative decomposition to SiO2 is provided and introduced directly into the flame of a combustion burner, thereby forming finely divided amorphous soot. The amorphous soot is deposited on a receptor surface where, either substantially simultaneously with or subsequently to its deposition, the soot is consolidated into a body of fused silica glass. The invention further relates to an apparatus for forming fused silica from liquid, preferably halide-free, silicon-containing reactants which includes: a combustion burner which, in operation, generates a flame; an injector for supplying a liquid silicon-containing compound to the flame to convert the compound by thermal oxidative decomposition to a finely divided amorphous soot; and a receptor surface on which the soot is deposited.
摘要:
The invention provides improved methods for reducing polarization mode dispersion (PMD) in single mode fiber by spinning the fiber during the drawing process in accordance with a spin function having sufficient harmonic content to achieve low levels of PMD for commercial fibers for which the beat lengths of the fibers, including the beat lengths of different portions of the fibers, are variable and thus not readily known in advance. The spin functions of the invention take advantage of certain resonances in energy transfer between polarization modes to achieve substantial reductions in PMD for a wide range of beat lengths. Examples of suitable spin functions include frequency-modulated and amplitude-modulated sine waves.
摘要:
The present invention is directed to a method for making silica glass and silica glass preforms. A liquid, preferably halide-free, silicon-containing compound capable of being converted by thermal oxidative decomposition to SiO.sub.2 is provided and introduced directly into the flame of a combustion burner, which converts the compound to silica, thereby forming finely divided amorphous soot. The soot is vaporized proximate the site where the liquid is converted into silica glass by atomizing the liquid, preferably with a stream of atomizing gas. A heater proximate the burner face and around the burner flame increases soot capture rate and allows for a reduction of the velocity of the atomizing gas. The amorphous soot is deposited on a receptor surface where, either substantially simultaneously with or subsequently to its deposition, the soot is consolidated into a body of fused silica glass.
摘要:
The invention provides improved methods for reducing polarization mode dispersion (PMD) in single mode fiber by spinning the fiber during the drawing process in accordance with a spin function having sufficient harmonic content to achieve low levels of PMD for commercial fibers for which the beat lengths of the fibers, including the beat lengths of different portions of the fibers, are variable and thus not readily known in advance. The spin functions of the invention take advantage of certain resonances in energy transfer between polarization modes to achieve substantial reductions in PMD for a wide range of beat lengths. Examples of suitable spin functions include frequency-modulated and amplitude-modulated sine waves.