| 摘要 |
PURPOSE:To obtain the light amplifying fiber having high efficiency in converting the excitation light into induced-emission light and capable of being applied in a long-distance optical communication system by substituting O ion close to Er with a specified anion in the Er-addition light amplifying quartz fiber provided with a wave directing function by the difference in the refractive index between the core and clad. CONSTITUTION:The Er ion dispersed in the quartz fiber provided with a wave directing function by incorporating Ge, etc., into the core to make the refractive index of the core higher than that of the clad is optically excited, and the signal light propagating in the fiber is amplified by the induced-emission light. In the Er-addition light amplifying quartz fiber, the O ion close to Er ion is locally substituted with an anion capable of increasing the asymmetry in the ligand field of the Er ion, e.g. F<->, Cl<-> and S2<-> to enhance the amplification efficiency of the fiber. The concn. of the substituent ion is kept low so that the consistency with the transmission fiber is not hindered. |
