Abstract:
A known quartz glass crucible for crystal pulling consists of a crucible wall, having an outer layer which is provided in an external area thereof with a crystallisation promoter which results in crystallisation of quartz glass, forming cristobalite when the quartz glass crucible is heated according to specified use in crystal pulling. The aim of the invention is to provide a quartz glass crucible which has a long service life. As a result, the crystallisation promoter contains, in addition to a silicon, a first component which acts as a reticulating agent in quartz glass and a second component which is free of alkali metals and which acts as an agent forming separating points in quartz glass. The above mentioned components are contained and incorporated into a doping area (8) of the outer layer (6) having a layer thickness of more than 0.2 mm.
Abstract:
Highly durable silica glass containing 0.01% to 2% by weight of at least one element selected from magnesium, calcium, strontium, barium, yttrium, hafnium and zirconium. The silica glass is produced by melting a powdery material comprising a finely divided silica powder and a finely divided zirconium-containing substance by oxyhydrogen flame or plasma are to form an accumulated molten material layer, and extending the molten material layer outwardly in radial directions.
Abstract:
A preform for a low loss fiber optic cable and method and apparatus for fabricating such a preform is provided. The method includes providing AlCl3 and CVD precursors and locally doping CaCl3. Alkali and/or alkaline earth fluxing agents can be introduced. The alkali and/or alkaline earths are doped along with the aluminum into the silica glass core.
Abstract:
High silica glasses exhibiting blue color by transmitted light are produced by impregnating a porous, high silica glass with a solution of cobalt, aluminum, and selected alkaline earth or alkali salts, and then consolidating the glass under oxidizing conditions to dope the glass with the corresponding oxides. The tinted glass has particular utility as a blue filter for lighting applications.
Abstract:
Disclosed in the application are a synthetic silica glass having low fluence-dependent transmission, particularly at about 193 nm, and a process for making the same. The glass may desirably exhibit a low level of fluorescence at 290 and 390 nm when activated at about 248 nm. The glass may desirably exhibit low level of LIWFD, [SiH*] and/or [ODC].