DEVICE FOR PRODUCING PREFORM OF OPTICAL FIBER

摘要

PURPOSE:To obtain a glass pipe extremely reduced in the eccentricity of its wall thickness or an optical fiber preform extremely reduced in the eccentricity of its core. CONSTITUTION:A method for producing an optical fiber base material by rotating a starting base material 11 held with a starting base material-holding bar 13 on the vertical axis, simultaneously lifting the starting base material 11, and subsequently depositing glass fine particles 16 on the outer peripheral surface of the starting preform, the glass fine particles being produced by hydrolyzing a glass raw material in a flame, is characterized in that a weight 21 for holding the starting base material in the vertical direction is hung from the lower end of the starting base material 11.