| 摘要 |
PURPOSE:To obtain a material for optical transmission containing a doped silica layer, stable to thermal history and having a low refractive index as a clad, by using BBr3 and SiF4 as an additive as a dopant for SiCl4 producing silica by oxidation using external heating. CONSTITUTION:SiCl4 is kept at a constant temperature in a thermostatic chamber, and O2 as a carrier gas and BBr3 and SiF4 as a dopant in specific amounts are mixed in a mixer and introduced into a quartz glass reaction tube. The reaction tube is heated from the outside by using an oxyhydrogen flame, high-frequency furnace, etc., and rotated at a constant speed by a rotating mechanism. A required thickness of silica is deposited as a clad, and a quartz glass rod 1 consisting of a high-purity quartz glass is inserted thereinto to give a core, and the heating temperature is increased to fuse the high-purity quartz glass rod. The resultant material is then drawn into wires to give the aimed material for optical transmission. |
