MANUFACTURE OF LIGHT TRANSMITTING GLASS FIBERS

摘要

PURPOSE:To obtain a preform having a uniform refractive index outside the core, by laminating fine glass particles for cladding with a constant dopant concentration on a cylindrical material of fine glass particles. CONSTITUTION:Fine glass particles for cladding are fed from the concentric multipipe burner 10 to the side of a glass particle cylinder with an almost parabola distribution of refractive index for core and laminated in a layer of constant thickness. The raw gas for cladding glass with a uniform concentration of dopant is fed to the burner 10. The seed rod 7 is lifted at such a speed as to make the distance between the burner 1 and the cylinder 8 constant. The refractive index distribution of the core is very nearly the parabola, and the graded index-type fiber comprising the cladding 17 of uniform refractive index can be obtained.