OPTICAL FIBER FOR AMPLIFICATION

摘要

PURPOSE:To remove concentration quenching in the subject optical fiber for amplification used as a light-amplifying element and to enable a high gain by doping the inside of the quartz-based core or the outer periphery part thereof with a specified quantity of Er and P. CONSTITUTION:The subject optical fiber 1 for amplification is composed of a quartz-based glass core 2 having a circular cross-section and a quartz-based glass clad 3 therearound having a lower refractive index than that of the core 2. The inside 2 of the core or the outer periphery part of the core 2 is doped with Er in combination with Ge and P and the amount of doping Er is limited within a range of <=100ppm for minimization of micro-coagulation in the optical fiber. By using P together with Er for the above-mentioned doping, tendency to coagulation of Er can be lowered and uniform dispersion can be contrived therefor.