Abstract:
A continuous sol-gel process for producing silicate-containing glasses and glass ceramics is proposed, comprising the following steps:
(a) continuously feeding a silicon tetraalkoxide, a silicon alkoxide with at least one non-alcoholic functional group and an alcohol into a first reactor (R1), and at least partially hydrolyzing by the addition of a mineral acid to obtain a first product stream (A); (b) continuously providing a second product stream (B) in a second reactor (R2) by feeding a metal alkoxide component or continuously mixing an alcohol and a metal alkoxide component; (c) continuously mixing product streams (A) and (B) in a third reactor (R3) for producing a presol to obtain a third product stream (C); (d) continuously adding water or a diluted acid to the product stream (C) to obtain a sol (gelation); (e) continuously filling the emerging sol into molds to obtain an aquagel; (f) drying the aquagels to obtain xerogels; (g) sintering the xerogels to obtain silicate-containing glasses and glass ceramics.
Abstract:
The invention relates to a method for producing a doped SiO2 slurry in which an SiO2 suspension is brought into interaction with at least one doping solution, wherein the SiO2 suspension and/or the doping solution act on one another in the form of an atomized spray, the average droplet diameter of which is in the range between 10 μm and 100 μm. The invention further relates to the use of an SiO2 slurry doped by the atomized spray method for the production of doped quartz glass, particularly for the production of laser-active quartz glass.
Abstract:
An optical fiber containing an alkali metal and capable of reducing Rayleigh scattering loss is provided. An optical fiber has a core and a cladding made of silica glass and enclosing the core. The cladding contains fluorine and has a refractive index lower than the refractive index of the core. The core contains first group dopants selected from the group of Na element, K element, or a compound thereof at an average concentration of 0.2 ppm or more and 10 ppm or less. The core also contains second group dopants for reducing the viscosity of silica glass and having a diffusion coefficient of 1×10−12 cm2/s or more and smaller than the diffusion coefficient of the first group dopants, by an average concentration of 0.2 ppm or more at a temperature of 2000° C. to 2300° C.
Abstract:
A method and apparatus for making a substantially void-free preform for a microstructured optical fiber using a one-step process is provided. A preform is prepared from specialty glasses using a direct extrusion method. A die for use with the direct extrusion method is also provided, and a method for drawing the preform into a HC-PBG fiber for use in transmitting infra-red wavelength light is also provided. The preform comprises an outer jacket made of solid glass, a cladding having a plurality of air holes arranged in a desired pattern within the jacket, and a core which is hollow.
Abstract:
A method for forming a silica glass blank includes generating soot using an array of soot producing burners, directing the soot along a first direction onto a bait, collecting the soot on the bait, imparting relative oscillatory motion having a repeat period between the array of soot producing burners and the bait along a second direction orthogonal to the first direction while collecting the soot, and offsetting the relative oscillatory motion by a selected distance along the second direction after each repeat period.
Abstract:
An apparatus for manufacturing a glass perform, includes: a dummy tube section, a reservoir portion, and a cooling portion; and a glass tube section in which particles of an alkali metal compound or an alkaline earth metal compound which have flowed into the glass tube section from the dummy tube section are heated by a second heat source which performs traverse, and oxides of the particles being deposited on an inner wall and dispersed in the glass tube section. In the cooling portion of the dummy tube section, vapor of the alkali metal compound or the alkaline earth metal compound generated by heating of a first heat source is cooled and condensed by a dry gas flowing into the dummy tube section, and thereby the particles are generated.
Abstract:
The invention is directed to the production of optical fibers from optical fiber preforms using flow physics. The present methods provide for the nulldrawingnull of an optical fiber preform using focusing of the preform by a surrounding fluid, e.g. a heated gas.
Abstract:
The present invention is directed to a method for making silica. 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, which converts the compound to silica, thereby forming finely divided amorphous soot. The soot is vaporized at the site where the liquid is converted into silica by pneumatically atomizing the liquid with a stream of oxygen gas, or a mixture of oxygen gas and nitrogen 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.
Abstract:
An active single-mode optical fiber has the core made of a rare earth doped non-oxide glass and the cladding made of an oxide glass. The glass of the core has a melting temperature lower than that of the glass of the cladding and lying within the range of the softening temperatures of the latter. In a preferred embodiment the core is made of a chalcogenide glass and the cladding is made of a lead silicate glass. To produce the fiber, a preform, obtained by introducing an element made of the non-oxide glass into the hole of a capillary tube made of the oxide glass, is brought to a temperature lying within the range of softening temperatures of the oxide glass and not lower than the melting temperature of the non-oxide glass, and is drawn. The capillary tube, during the drawing process, serves as a container for the molten glass of the core.