| 摘要 |
PURPOSE:To obtain an optical fiber, having improved radiation resistance characteristics, and suitable for use in environment of radiation, by heating a soot containing OH groups added to a core part in an atmosphere of oxygen, and spinning the resultant vitrified soot. CONSTITUTION:Oxygen gas is made to flow in a furnace core tube 2 in an electric furnace 1 provided around the core tube 2. A soot 3 having OH groups added to a core part is introduced into the furnace core tube 2 while rotated and vitrified under heating. Thus, the silicon atoms unlinked to oxygen are linked to the diffused oxygen as shown in the formula, and the diffusion path is formed due to the high self-diffusion coefficient of the OH groups added to the soot 3. Thus, the apparent self-diffusion coefficient of the oxygen passing through the path is increased to cause the reaction in the whole soot 3, eliminate the structural defects and improve the radiation resistance. The resultant vitrified preform is then drawn to give the aimed titled optical fiber. |
