Spectral properties of Pr:CNGG crystals grown by micro-pulling-down method

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 ¹D₂ energy level is also determined. The results indicate that Pr:CNGG crystal could be a potential solid-state laser gain medium.