VITRIFYING PREFORM OF OPTICAL FIBRE

摘要

A glass preform for use in the fabrication of an optical fiber having less hydroxyl groups is produced with good reproducibility by a method comprising steps of synthesizing glass soot particles from a glass-forming raw material, depositing the glass soot particles on a rotating starting member to form a porous glass preform, heating the porous preform under pressure in a specific range at a temperature at which hydroxyl groups are removed from the preform and the preform is vitrified to produce a transparent glass preform. A new apparatus for vitrifying a porous soot preform is also disclosed.