| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical fiber preform which, specifically, is able to suppress outer diameter fluctuations in the preform in the area where the drawing of a preform ingot ends and to obtain a preform of uniform diameter in the longitudinal direction. <P>SOLUTION: The method for manufacturing the optical fiber preform comprises steps of manufacturing a porous glass preform 6 by producing silica powder from a compound containing silicon, obtaining a preform ingot 10 by sintering and vitrifying the porous glass preform 6 at a high temperature, and drawing and diameter-reducing the preform ingot 10 by adding tension on a heated portion while sequentially moving a heating means in a relative manner along the longitudinal direction of the preform ingot 10, wherein an unsintered portion 11, which has not been completely vitrified, at one end of the sintered preform ingot 10 is left, and drawing is begun from the unsintered portion 11 in the drawing and diameter-reducing step. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
