Method for producing glass preform for optical fiber.

摘要

A method for producing a glass preform (1) comprising flame hydrolyzing a glass raw material in an oxyhydrogen flame to form glass fine particles of quartz, depositing the glass fine particles on a seed member to produce a solid or hollow cylindrical soot preform (1) at least of a part of which contains GeO2, and heating and sintering the soot preform (1) by introducing it in an atmosphere comprising an inert gas (6) at least a part of which is kept at a temperature not lower than 1,600°C at an introducing rate not smaller than 3 mm/min, from the glass preform produced by which method, an optical fiber having longitudinally homogeneous composition and low attenuation of light transmission can be fabricated.