1.3 MU-M FLUORESCENCE QUENCHING IN PR-DOPED GLASSES

Short fluorescence lifetime is the main problem encountered in designi ng an efficient Pr3+-doped amplifier at 1.3 mu m. Lifetimes observed i n low phonon energy glasses are far shorter than those indicated by ca lculations. We examine 1.3 mu m fluorescence quenching in Pr3+-doped g lasses via concentration and impurity quenching in order to estimate t he limits on metastable lifetimes achievable in low-doped, low-impurit y glasses. The optimum doping level and the requirements for impurity content are assessed. Three glass hosts are studied in detail; cadmium -halide, gallium-indium-fluoride, and germanium-gallium-sulphide. The prospects for extending the Pr3+ metastable lifetime in these glasses are considered. (C) 1998 American Institute of Physics. [S0021-8979(98 )04316-3]