PRODUCTION OF PREFORM FOR OPTICAL FIBER

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a preform for an optical fiber by which a glass microparticle layer having a small fluctuation of outside diameter can be deposited on the outer periphery of a starting member according to an outside vapor-phase deposition method. SOLUTION: This method for producing a preform for an optical fiber is to move the position of a starting point when reciprocating an oxyhydrogen flame burner 2 for each one reciprocation in the method for producing the glass preform for the optical fiber comprising introducing a glass raw material gas into the oxyhydrogen flame burner 2 reciprocating in the longitudinal direction of a rodlike starting member 1 while rotating the rodlike starting member 1 around the shaft thereof, generating glass microparticles by flame hydrolysis and depositing the glass microparticles on the outer periphery of the starting member 1. The moving width thereof is preferably prevented from becoming the same as the pitch width of the fluctuation of the outside diameter of the glass microparticle layer 3 after the deposition. The speed of the reciprocation of the burner 2 is more preferably reduced as the amount of the deposited glass microparticles is increased.