Growth and spectroscopic properties of Tm3+ and Tb3+ co-doped GdScO3 crystal

Abstract

GdScO3 single crystal codoped with Tm3+ and Tb3+ ions was successfully grown by the Edge-defined Film-fed Growth Method (EFG) for the first time. Absorption, fluorescence spectrum and fluorescence lifetimes of the grown crystal at room temperature were measured. The absorption cross-section at 789 nm was calculated to be 8.20 × 10−21 cm2. The emission cross-section was 1.35 × 10−21 cm2 at 1504 nm with the FWHM of 95.3 nm. The fluorescence lifetimes of the 3H4 state and the 3F4 state were fitted to be 253 μs and 1460 μs, respectively. Compared with Tm3+ single doped GdScO3 crystal, the codoping of Tb3+ successfully depopulated the 3F4 energy level and enhanced the emission at 1.5 μm region. It indicated that Tm,Tb:GdScO3 could be favorable laser medium for 1.5 μm-laser operation.