Growth, spectroscopy, and laser performance of a radiation-resistant Cr,Yb,Ho,Pr:GYSGG crystal for 2.84 µm mid-infrared laser

A new Cr3+, Yb3+, Ho3+, and Pr3+ co-doped GYSGG (Gd2YSc2Ga3O12) single crystal with a size of Φ 26 mm × 80 mm was grown successfully using the Czochralski method for the first time. Absorption spectrum is studied, and main absorption bands are centered at 449, 638, and 934 nm. The fluorescence spectrum shows a broad emission band around 2.8 µm, indicating the Cr3+ and Yb3+ ions can act as the sensitizer for the Ho3+ ions. The fluorescence lifetimes of the 5I6 and 5I7 levels of the Ho3+ ions are fitted to be 0.39 and 5.31 ms, respectively. By comparison with those of the Cr,Yb,Ho:GYSGG crystal, the Pr3+ ions acting as the deactivator can decrease efficiently the lifetime of the lower laser level 5I7 of the Ho3+ ions. Additionally, a flash lamp pumping 2.84 µm laser with maximum average power of 257 mW is achieved. These results indicate the Cr,Yb,Ho,Pr:GYSGG crystal is a new promising radiation-resistant laser gain medium applied in radiant environment.