| 摘要 |
PURPOSE:To manufacture the title material free from chlorine, and to prevent the absorption loss at wavelengths of 0.7 - 1.1mum, by vitrifying a porous preform after the removal of OH groups with a gas stream containing Cl2 gas in a heating furnace. CONSTITUTION:The porous preform 32 formed under the base 30 by gaseous phase axial deposition is lowered while being rotated slowly, then heated by the heater 12 of the furnace 11 at 400 - 500 deg.C, and subjected to the OH removal reaction in the atmosphere of CC 4 together with He gas fed from the inlet 14. An inert gas, e.g. He, is fed from the inlet 26, and passed through the furnace 21 to vitrify the preform 32 under heating with the element 22, thus desorbing Cl2 in the SiO2 glass. Optical fibers manufactured from the material 34 have no absorption loss at wavelengths 0.7 - 1.1 mum due to Cl2. |
