| 摘要 |
PURPOSE:To produce a large-sized heavy preform for an optical fiber. CONSTITUTION:Gaseous starting material for glass is jetted from a multiply- tubed burner, oxidized and hydrolyzed in an oxyhydrogen flame, the resulting fine glass particles are deposited on the periphery of a rotating starting member grasped by a chuck to form a porous glass preform and this preform is converted into transparent glass by sintering at a high temp. to produce a preform for an optical fiber. At this time, after a prescribed amt. of the porous glass preform is deposited, the surface of the preform is heated so as to increase the deposition density of the outermost layer of the preform to such a degree that strength sufficient to directly grasp the preform is ensured and the body of the effective part of the preform is directly grasped by a jig and detached from the chuck. |
