OPTICAL FIBER BASE MATERIAL MANUFACTURING METHOD AND OPTICAL FIBER

摘要

PROBLEM TO BE SOLVED: To provide a method capable of manufacturing an optical fiber base material having plural holes extending in a longitudinal direction at low costs and with high accuracy.SOLUTION: In an optical fiber base material manufacturing method according to the present invention, a jacket is formed around a core material to manufacture an optical fiber base material. The method includes: a starting material manufacturing step of manufacturing a starting material 10 by adding a third region 13 with larger viscosity than that of the core material outside of the core material comprising a first region 11 and a second region 12 surrounding the first region 11; an accumulation step of accumulating glass fine particles around the starting material 10; and a sintering step of forming the jacket by sintering the accumulating glass fine particles and making them transparent. Ge is added to the first region 11. Cl or F is added to the second region 12, and the second region 12 has plural holes 14 extending in a longitudinal direction. At temperatures of 1300-1700°C during the sintering step, a viscosity of the third region 13 is larger than that of the second region 12.