Spectroscopic properties of a Cr3+, Er3+ and Pr3+ co-doped CaLu0.2La0.8Ga3O7 single crystal for a 2.7 μm laser

Abstract A new laser crystal, Cr/Er/Pr:CaLu 0.2 La 0.8 Ga 3 O 7 (Cr/Er/Pr:LuCLGO), was successfully grown by the Czochralski method for the first time. The structural parameters of Cr/Er/Pr:LuCLGO crystal were determined by the x-ray Rietveld refinement method. Optical absorption, fluorescence spectra and lifetime decay profiles were measured for the crystal. The co-doped Cr 3+ ion expands the absorption cross-section considerably for 400–700 nm bands, which is beneficial for xenon lamp pumping. Also the co-doped Pr 3+ ions decrease the population of the Er 3+ : 4 I 13/2 energy state effectively. The energy transfer efficiencies of the Er 3+ : 4 I 11/2 → Pr 3+ : 1 G 4 and Er 3+ : 4 I 13/2 → Pr 3+ : 3 F 4 processes were calculated, showing that Pr 3+ ions can play an important role as deactivators for Er 3+ ions. Furthermore, the energy transfer mechanisms among Cr 3+ , Er 3+ and Pr 3+ ions were studied. The results suggest that Cr/Er/Pr:LuCLGO crystal is a new promising laser medium for 2.7 μ m xenon lamp pumping solid-state lasers.