MANUFACTURE OF OPTICAL FIBER BASE MATERIAL

摘要

PURPOSE:To obtain an optical fiber base material having a desired refractive index by controlling a position of a porous glass body depositing face on which a dark line existing at the center of a flow of glass fine particles is sprayed. CONSTITUTION:By spouting glass synthesizing materials from the central nozzle of concentric multitubed burner 1 with oxyhydrogen flame 2, SiCl4 contained in the materials in a largest amount is immediately converted into glass fine particles 3 of SiO2 by flame hydrolysis. Particles 3 scatter light and shine white, yet a flow of unreacted materials exists at the center of the flow of particles 3 and appears as dark line 4. The relative positional relation between line 4 and porous glass body 6 is controlled by spraying line 4 on an almost central part of body 6.