Spectral properties of Pr:CNGG crystals grown by micro-pulling-down method**Project supported by the National Key Research and Development Program of China (Grant No. 2016YFB0701002), the National Natural Science Foundation of China (Grant Nos. 61621001 and 61605069), and the MOE Key Laboratory of Advanced Micro-Structured Materials, China.

Abstract

Pr3+-doped calcium niobium gallium garnet (Pr:CNGG) single crystals with different Pr3+concentrations are successfully grown by the micro-pulling-down (μ-PD) method. The crystal structure, room-temperature absorption spectra, and fluorescence spectra of Pr:CNGG crystals are measured and discussed. The fluorescence results indicate their large dependence on the doping concentration. The fluorescence lifetime of the energy level is also determined. The results indicate that Pr:CNGG crystal could be a potential solid-state laser gain medium.