Manufacture of optical fiber base material

Abstract

Abstract PURPOSE:To obtain an optical fiber base material having superior characteristics in loss in great quantities by hydrolyzing glass forming starting materials in liq. phase after which the resulting silicic acid gel is dehydrated in a halogen gas atmosphere and transparently vitrified by heating at a high temp. CONSTITUTION:A mixture of SiCl4 and GeCl4 as starting materials 6 for a core is spouted into thin-walled pipe 2, and SiCl4 as starting material 7 for a clad into container 1. By spouting distilled water 9, 10, Si(OH)4 and Ge(OH)4 are formed by hydrolysis, and they are allowed to stand to accelerate polymn. reaction and hardened. Pipe 2 is then pulled out, and after a time container 1 is removed to obtain cylindrical gelled base material 24 composed of core gel and clad gel. Material 24 is mounted on rotary support 23 in the electric furnace for dehydration and transparent vitrification, and it is heated while feeding a gaseous halide such as SOCl2 or Cl2 as a dehydrating agent to core tube 21 from feeder 26 together with He gas. Thus, material 24 is converted into an OH group-free transparent base material by shrinkage at about 1,200 deg.C.

Inventors

• 👤 Masao Kawachi
• 👤 Shoichi Sudo
• 👤 Noriyoshi Shida
• 👤 Takao Edahiro

Bibliographic Details