摘要:
An alkali-metal-doped core optical fiber having high hydrogen resistance and a method for manufacturing such an optical fiber are provided. A method for manufacturing a deuterium-treated optical fiber according to the present invention includes a preform-forming step of forming a silica glass optical fiber preform having a core doped with an alkali metal element, a drawing step of drawing the optical fiber preform to form an optical fiber, and an exposing step of exposing the optical fiber to a deuterium gas atmosphere. Alkali-metal-doped core optical fibers can be manufactured by using this method. In the exposing step, the optical fiber is exposed to an atmosphere containing deuterium gas at a temperature of 20°C or more under conditions where (deuterium gas partial pressure) × (exposure time) is 50 kPa·hour or more.
摘要:
A chemical vapor deposition method which utilizes a rare earth chelate vapor as a source of rare earth ions for producing an optical fiber having a core with a high rare earth content.
摘要:
A glass optical waveguide preform is formed by chemical reaction of gaseous and/or vapourised ingredients (A and B) within a glass substrate tube (52). A reactant feed tube (50) extends Into a first end of the substrate tube (52). One of the reactants (A) flows through the feed tube (50), and another (B) flows through the annular channel between the feed (50) and substrate (52) tubes. The reactants (A and B) combine just downstream of the end of the feed tube (54) and react to form particulate material, of which at least a portion is deposited on the substrate tube (52). The output end of the feed tube (50) traverses (58, 60) the substrate tube (52) so that the region of maximum soot deposition moves along the length of the substrate tube. A hot zone (54, 56) traverses (18a', 18b') the substrate tube (52) in synchrony (58) with the feed tube (50) to sinter the deposited soot.