| 摘要 |
<p>The present invention provides a method of manufacturing an optical fiber preform that obtains a preform having a uniform diameter across its longitude and in which the change in the outer diameter of the preform is restricted, particularly in a region where the extension is finished. A method of manufacturing an optical fiber preform, that involves generating silica powder from a compound containing silicon to manufacture a porous glass base material, sintering and vitrifying the porous glass base material at a high temperature to obtain a base material ingot, while relatively moving a heating means in a longitudinal direction of the base material ingot, and applying a tensile force to a heated portion to decrease a diameter of and extend the base material ingot, the method comprising retaining an unsintered portion at one end of the sintered base material ingot that is not completely changed to glass and, during the extending, beginning extension from a side of the unsintered portion.</p> |
