| 摘要 |
PURPOSE:To secure a thremal resistance and a radiation resistance in a multiplex transmission of a specified wavelength by using an optical fiber having a quartz compound core containing an OH radial of a prescribed quantity and a quartz compound clad layer. CONSTITUTION:A composite cable is formed by bundling an optical fiber cable 5 which has used an optical fiber 4 as a strand, and a power line 6 made of a copper twisted wire, in a state that they are covered with an insulating material, winding a heat resistance plastic tape 8, and covering its outside with a sheath 9 made of silicone rubber. As for a method for setting an OH radical content in a core of the fiber 4 to 10-30ppm, a method for reducing it within a prescribed range, etc. by heating a quartz glass whose OH radical content is usually >=1,000ppm, in a chlorine gas atmosphere, etc. are used. |
