| 摘要 |
PURPOSE:To suppress the generation of oxygen defects in an optical fiber, and to prevent the increase in the transmission loss with time, by carrying out the dehydration treatment of a soot preform for an optical fiber in an atmosphere containing oxygen gas. CONSTITUTION:The soot preform 10 placed in the furnace 12 (the sign 14 is a heater) is dehydrated in the atmosphere of the gas introduced from the inlet 16 and discharged from the outlet 18. In the above process, He gas containing chlorine gas and oxygen gas is used as the gas for passing through the furnace 12. The effect can be promoted by pressurizing the atmosphere (accordingly the oxygen gas is also pressurized) in the furnace with a pressure-controller 20. |
