| 摘要 |
PURPOSE:To accurately control the form of refractive index distribution in an optical fiber base material and enhance the optical fiber zone of the material by using a Ge cpd., as glass raw material, which is hydrolyzed or thermally oxidized with reaction efficiency and rate equal to or higher than those of SiCl4. CONSTITUTION:GeH4-base glass raw material from pass I and mixed gas of GeH4 and SiCl4 from passes II, III are supplied to raw material spouting hole 73, diffused, spouted from the synthesis torch, and hydrolyzed or thermally oxidized to SiO2 and GeO2, forming glass particles. Using GeH4 as a Ge cpd. reactions of SiCl4 SiO2 and GeH4 GeO2 take place at the same position p, no unreacted Ge cpd. is spouted from the torch, GeH4 concn. distribution formed in the torch can be allowed to approximate to GeO2 concn. distribution in the resulting porous base material, whereby glass fine particles are produced without disturbing the distribution in the torch. |
