Method of producing optical waveguide

摘要

A method for producing an optical waveguide by melt-drawing a transparent glass rod which has been produced by collapsing a porous glass rod after being doped with a dopant material by depositing said material on the surface of the micro pores in order to enhance the refractive index of the collapsed glass rod, wherein a waveguide having higher mechanical strength and lower transmission is attained by drawing said glass rod at a temperature very close to the melting point of the outermost portion of the fiber without causing any overmelting or bubbling in the core portion, said drawing being facilitates by matching the viscosity and characteristics of the outermost lower-refractive-index portion to those of the central higher-refractive-index portion.