METHOD FOR PRODUCING DEUTERIUM-TREATED OPTICAL FIBER, AND DEUTERIUM-TREATED OPTICAL FIBER

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.