| 摘要 |
PURPOSE:To reduce an optical transmission loss being a radiant ray characteristic by specifying a ratio of an optical fiber diameter against a core diameter, of an optical fiber having a core consisting of pure quartz glass, and a clad formed by doping boron and fluorine in quartz glass. CONSTITUTION:The titled optical fiber has a core consisting of pure quartz glass, and a clad formed by doping boron and fluorine in quartz glass, and a ratio of an optical fiber diameter against a core diameter 1 is larger than 2.5. In this way, when the ratio of the core diameter and the optical fiber diameter is set within a specified range, an increase quantity (DELTAalpha) of an optical transmission loss at the time of irradiating a radiant ray can be suppressed at a room temperature to <=13dB/km at the time of irradiation of the radiant ray after, for instance, 10<4>R/HX60min, and an increase of this optical transmission loss becomes endurable enough for use under the existence of the radiant ray. |
