METHOD OF PRODUCING OPTICAL FIBER AND BASE MATERIAL THEREFOR

摘要

A method of producing a material for single mode optical fiber comprises the steps of making a core rod from a vitreous substance, coating the core rod with a cladding layer to a desired diameter, and dehydrating and vitrifying it. When this material is drawn into optical fiber, the diameter of its core rod is at least 1.9 times the mode field diameter through which light having a wavelength of 1.55 mu m travels. As a result, the glass material for single mode optical fiber has small influences of structural defects.