摘要 |
A method for manufacturing an optical fiber preform and an optical fiber preform apparatus are provided which can reduce hydroxyl groups in an optical fiber preform to a sufficient level without requiring any special equipment or operating conditions. When an optical fiber preform is manufactured by the vapor-phase deposition method, the dehydrating treatment is performed on a porous core preform that is obtained by depositing glass microparticles. In this treatment, a dehydrating agent is supplied to a dehydration apparatus through a feeding pipe and a main feeding pipe made of a material having a water permeance factor of 1.0x10-11 g.cm/cm2.s.cmHg or less, thereby manufacturing an optical fiber preform.
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