| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an optical fiber preform stably having a large relative index difference in the longitudinal direction without producing a rough surface on a glass layer surface deposited on the lower part of a rod. <P>SOLUTION: The method of manufacturing the optical fiber preform includes feeding at least a glass raw material, a dopant material and oxygen to a high frequency induction thermal plasma torch to synthesize glass fine particles in the plasma flame and attaching and depositing the synthesized glass fine particles on the surface of the glass rod which rotates and reciprocates relative to the plasma torch. The glass raw material is fed only on the forward way of the reciprocating movement, and the plasma power in the forward way is increased, for a predetermined time in the early stage of the forward way, to a level higher than the plasma power in the stationary state thereafter, and the glass fine particles produced are deposited on the glass rod. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
