METHOD FOR PRODUCING GLASS PREFORM FOR OPTICAL FIBER

摘要

A rod-in-tube method for producing a glass preform for use in the fabrication of an optical fiber, which comprises steps of inserting a glass rod as a core material in a glass tube as a cladding material, fusing and closing one end of the cladding material, filling a gap between the core and cladding materials with an atmosphere containing at least one gaseous halogen-containing compound and then heating the core and cladding materials at a temperature not lower than 1,900 DEG C. to collapse the gap between them and to fuse them together, from which glass preform, an optical fiber with low attenuation of light transmission is fabricated.