Abstract:
The invention relates to a method for preparing doped oxide material, in which method substantially all the reactants (B, D) forming the oxide material are brought to a vaporous reduced form in the gas phase and after this to react with each other in order to form oxide particles (P). According to the invention, said reactants (B, D) in vaporous and reduced form are mixed together to a gas flow (BD) of reactants, which gas flow (BD) is further condensated fast in such a manner that substantially all the component parts of the reactants (B, D) reach a supersaturated state substantially simultaneously by forming oxide particles (P) in such a manner that there is no time to reach chemical phase balances.
Abstract:
A method of making fused silica includes generating a plasma, delivering reactants comprising a silica precursor into the plasma to produce silica particles, and depositing the silica particles on a deposition surface to form glass.
Abstract:
Bei dem Verfahren wird das Gas für die reaktive Abscheidung des Glasmaterials durch einen den stab- oder rohrförmigen Ausgangskörper (1) umgebenden Kanal (2) geleitet. Für die Außenbeschichtung des Ausgangskörpers (1) wird in dem Kanal (2) eine den Ausgangskörper umgebende Plasmazone (3) durch einen Resonator (4) erzeugt, wobei eine Abscheidung von Glasmaterial an der Innenwand des Kanals (2) entweder dadurch verhindert oder zumindest minimiert wird, daß die Feldstärke des Resonators (4) an der Innenseite des Kanals (2) gering ist. In einer anderen Ausführungsform kann an der Innenseite des Kanals (2) eine Schutzgasschicht, wie eine Sauerstoffströmung, aufrechterhalten werden, so daß an der Innenwand des den Ausgangskörper (1) umgebenden Kanals (2) keine wesentliche Abscheidung von Glasmaterial erfolgt. Hierdurch können insbesondere Vorformen zur Herstellung von Lichtwellenleitern mit großem Kern/Mantelverhältnis in kontrollierten Atmosphären mit gutem Gasausnutzungsgrad hergestellt werden.
Abstract:
An image fiber preform for use in an image fiber according to the present invention includes a plurality of optical fiber strands, each optical fiber strand including a silica glass core which contains a dopant for increasing a refractive index of the core and a silica glass cladding surrounding the silica glass core, the silica glass cladding containing a fluorine dopant for decreasing a refractive index of the cladding, the cladding having an outer peripheral surface, and a quartz tube in which the optical fibers are closely arranged, wherein the cladding has a concentration of the fluorine dopant which decreases radially outward toward the outer peripheral surface of the cladding. In the present invention, an image fiber prepared from the image fiber preform and fabrication processes for the image fiber preform and the image fiber are provided.
Abstract:
An image fiber preform for use in an image fiber according to the present invention includes a plurality of optical fiber strands, each optical fiber strand including a silica glass core which contains a dopant for increasing a refractive index of the core and a silica glass cladding surrounding the silica glass core, the silica glass cladding containing a fluorine dopant for decreasing a refractive index of the cladding, the cladding having an outer peripheral surface, and a quartz tube in which the optical fibers are closely arranged, wherein the cladding has a concentration of the fluorine dopant which decreases radially outward toward the outer peripheral surface of the cladding. In the present invention, an image fiber prepared from the image fiber preform and fabrication processes for the image fiber preform and the image fiber are provided.
Abstract:
Glass preforms for optical fibers or the like having refractive index profiles which vary in stepped or graded fashion across the preform, are made from porous glass preforms by introducing a first dopant into the porous preform during manufacture, partially sintering the preform to selectively modify the internal surface area thereof, introducing a second vapor-infusible dopant into the selectively sintered preform to cause selective doping of the porous glass, and then consolidating the resulting doped preform to clear glass.
Abstract:
Hydroxyl free deposition with high efficiency and at a high deposition rate may be achieved, even with use of relatively inexpensive raw materials, by utilizing a ring-shaped plasma activated axial chemical vapor deposition obtaining 100% chemical conversion and fractional volatilization of impurities. The plasma (2) is induced in an annular stream of a plasma-forming gaseous medium, and the reactant or reactants used in the axial chemical vapor deposition are introduced into the center of the ring-shaped plasma (2) to be converted by the heat of the plasma flame into glass precursor particulate which is deposited on a bait 4. An annular stream of a cooling medium flows outwardly past the plasma flame and is circumferentially centered by an extension (19) of the outer tubular element (9) of a plasma torch (1) in which the plasma is generated. An RF generator (18) which induces the plasma is operated at a frequency exceeding 20 MHz to give the plasma flame the desired ring-shaped configuration.