| 摘要 |
PURPOSE:To manufacture the titled base material having superior strength and a favorable refractive index distribution by subjecting a gaseous starting material diluted with a carrier gas to flame hydrolysis to form a porous glass body having a specified density. CONSTITUTION:A flame-hydrolyzable Si compound such as SiCl4 or trichlorosilane is diluted to <=30% with a carrier gas such as He or Ar, and by hydrolyzing this gaseous starting material in an oxyhydrogen flame, fine particles of silica or silica contg. a dopant are deposited to form a porous glass body having 0.03-0.15g/cm<3> density. The glass body is converted into transparent glass in a furnace at a high temp. Since this glass body has a large specific surface area, the substitution of halogen for OH groups can be conducted efficiently, so an optical fiber with a small transmission loss is obtd. |
