Patent ID: 7073354

Claim:
A method of manufacturing an optical fiber preform comprising the steps of: generating glass particles with an oxy-hydrogen flame discharged from a burner equipped with at least a first port that discharges a source material gas or a mixed gas of said source material gas and an additive gas provided in the center, and a second port that discharges an inert gas provided on the same central axis as said first port around said first port; manufacturing a porous optical fiber preform by depositing said glass particles in the radial direction of an outer periphery of a starting member; sintering said porous optical fiber preform; and maintaining a relationship between a flow rate vm (m/sec) of said source material gas or said mixed gas of said source material gas and said additive gas discharged from said burner, and a flow rate vs (m/sec) of said inert gas which eliminates adherence of said glass particles to an end surface of said burner such that âˆ’0.06 vm+1.4â‰¦vsâ‰¦âˆ’0.02 vm+1.8, and vsâ‰§0.40.