PRODUCTION OF BASE MATERIAL FOR OPTICAL FIBER

摘要

PURPOSE:To readily control the refractive index of a core and obtain the titled base material having improved transmission characteristics, by integrating a rod for the core and pipe for a clad in the state of rod-in-pipe while dehydrating and transparently vitrifying both in a halide-containing atmosphere. CONSTITUTION:A rod for a core 1 and a pipe for a clad 2 are made into a glass sintered material having both >=0.3g/mm<3> bulk density or either one thereof is made into the above-mentioned sintered material and the other is made into a porous material or transparent glass material. The rod 1 and pipe 2 are made into a state of rod-in-pipe, and a quartz glass pin 3 is inserted into the tip thereof to secure relatively both. A support rod 10 is mounted thereon, and the resultant assembly is put in a furnace core tube 7. SOCl2 bubbled with He and O2 is fed from a gas feeding system 5 into an electric furnace to heat the assembly with a heater 8 and the support rod 10 is then lowered to transparently vitrify the assembly. Thereby, the titled base material 9 having the integrated rod 1 and pipe 2is obtained.