| 摘要 |
PURPOSE:To produce the title optical fiber base material having an excellent UV-ray transmitting characteristic by depositing the fine particles of SiO2 on a quartz glass seed rod to form a porous body, and heating and vitrifying the porous body in a sintering furnace wherein He and Cl2 are charged and the inside of which is evacuated to a high vacuum. CONSTITUTION:The fine particles of SiO2 formed by hydrolyzing SiCl4 in an oxyhydrogen flame are deposited on the quartz glass seed rod 2 to form the porous body 3. The obtained porous body 3 is heated by carbon heaters 4 and 4' in the quartz glass furnace core tube 1 of the sintering furnace, and vitrified. In that case, He and Cl2 are charged into the furnace core tube 1, the inside is evacuated, and the pressure is reduced from atmospheric pressure to <=0.2mmH2O. By this method, the mixing of oxygen is reduced, and the optical fiber base material with an improved UV-ray transmitting characteristic is obtained. |
