Abstract:
A method for making silica includes delivering a silica precursor comprising a pseudohalogen to a conversion site and passing the silica precursor through a flame to produce silica soot. The pseudohalogen is selected from a group consisting of cyano, isocyano, cyanato, isocyanato, thiocyanato, isothiocyanato, selenocyanato, and isoselenocyanato. By suitable choice of pseudohalogen (also claimed) germanium oxide can be made. The silica and/or germania may be a soot powder or deposited on a substrate, such as a rod or tube to form an optical fiber preform or on a planar substrate to form a stepper lens preform used for microlithography processes. The pseudohalogen precursors are hydrogen-free and chlorine-free.
Abstract:
Suppression of stimulated Brillouin scattering (SBS) by broadening the energy spectrum of participating SBS photons and/or phonons is achieved in an optical fiber having a core with both radially nonuniform viscosity and CTE profiles provided by alternating layers of glass modifying dopants such as phosphorus and fluorine. The nonuniform thermal expansion and viscosity profiles impart a residual, permanent, nonuniform stress in the fiber. The SBS suppressing effect provided by the nonuniform stress can be controlled and enhanced by applying a uniform or nonuniform tensile force to the fiber as it is being drawn. A preform for the fiber is also disclosed.
Abstract:
Die Erfindung betrifft ein Verfahren zur Herstellung von synthetischem Quarzglas durch Verdampfen eines Polyalkylsiloxans als flüssigen SiO 2 -Einsatzmaterials (105), Umsetzen des SiO 2 -Einsatzdampfes (107) zu SiO 2 Partikeln, Abscheiden der SiO 2 Partikel unter Bildung eines Sootkörpers (200) und Verglasen des Sootkörpers (200). Erfindungsgemäß ist vorgesehen, dass das Verdampfen des erhitzten SiO 2 -Einsatzmaterials (105) eine Injektionsphase in einer Expansionskammer (125) umfasst, in der das SiO 2 -Einsatzmaterial (105) in feine Tröpfchen atomisiert wird, wobei die Tröpfchen einem mittleren Durchmesser von weniger als 5 pm aufweisen, und die Atomisierung der Tröpfchen in einem vorgewärmten Trägergasstrom stattfindet, der eine Temperatur von mehr als 180°C aufweist.
Abstract:
Übliche Solarstrahlungsempfänger sind mit einer Kammer zwecks Durchleitung eines Arbeitsgases ausgestattet, das zur Wärmeaufnahme an einem Absorber für Solarstrahlung entlang geleitet wird. Der Absorber ist mit einem kuppelförmigen Eintrittsfenster aus Quarzglas versehen, bei dem die dem Absorber zugewandte Innenseite beim bestimmungsgemäßen Einsatz eine nominale Innentemperatur Ti von mindestens 950 °C, vorzugsweise mindestens 1000 °C, annimmt, wohingegen die dem Absorber abgewandte Außenseite der Umgebung ausgesetzt ist und der Gefahr einer Entglasung unterliegt. In der Erfindung geht es darum, den bekannten Solarstrahlungsempfänger so zu modifizieren, dass eine hohe Absorbertemperatur einstellbar ist und damit eine hohe Effizienz der solarthermischen Aufheizung ermöglicht wird, und zwar ohne eine Vergrößerung der Gefahr einer Entglasung im Bereich der Außenseite des Eintrittsfensters.
Abstract:
An apparatus and process for making glass soot sheet and sintered glass sheet. Glass soot particles are deposited on a curved deposition surface (103) of a rotating drum to form a soot sheet. The soot sheet is then released from the deposition surface. The soot sheet can tie sintered into a consolidated glass. The soot sheet and the sintered glass can be sufficiently long and flexible to be reeled into a roll (117).
Abstract:
The present invention provides a synthetic quartz glass having a diameter of 100 mm or more for using in an optical apparatus comprising a light source emitting a light having a wavelength of 250 nm or less, the synthetic quartz glass having, in a region located inward from the periphery thereof by 10 mm or more in a plane perpendicular to the optical axis of the synthetic quartz glass: a birefringence of 0.5 nm or less per thickness of 1 cm with respect to a light having a wavelength of 193 nm; an OH group concentration of 60 ppm or less; an averaged differential OH group concentration from the center of the synthetic quartz glass toward a peripheral direction thereof, normalized with respect to the radius of the synthetic quartz glass, of -8 to +60 ppm,- and an unbiased standard deviation of a differential OH group concentration from the center of the synthetic quartz glass toward a peripheral direction thereof, normalized with respect to the radius of the synthetic quartz glass, of 10 ppm or less.
Abstract:
An optical fiber suitable to support single mode optical transmission at longer wavelengths (e.g., 1550 nm) is formed to comprise a pure silica core region and a "down doped" cladding layer. The core region is defined as having a diameter d and the cladding layer is defined has having an outer diameter D. In accordance with the present invention, single mode propagation wí11 be supported when D/d > 8.5, and is preferably in the range of 9 - l 0.
Abstract:
The present invention provides nanometer-sized diameter silica fibers that exhibit high diameter uniformity and surface smoothness. The silica fibers can have diameters in a range of a about 20 nm to about 1000 nm. An exemplary method according to one embodiment of the invention for generating such fibers utilizes a two-step process in which in an initial step a micrometer sized diameter silica preform fiber is generated, and in a second step, the silica preform is drawn while coupled to a support element to form a nanometer sized diameter silica fiber. The portion of the support element to which the preform is coupled is maintained at a temperature suitable for drawing the nansized fiber, and is preferably controlled to exhibit a temporally stable temperature profile.