PRODUCTION OF POROUS PREFORM FOR OPTICAL FIBER

摘要

PURPOSE:To provide a method for producing a porous preform capable of producing an optical fiber without being incorporate with metallic compd. and having sufficient strength. CONSTITUTION:A silica powder is agitated in an alkaline liq. phase to remove impurity particles in this silica powder, and the preform is produced by a powder molding method by using this silica powder as a main starting material.