Detailed polarized spectral properties of Tm3+:NaLa(MoO4)2 crystal have been investigated. The polarized absorption spectra, polarized fluorescence spectra, and fluorescence decay curves were measured at room temperature. The fluorescence decay mechanisms of the G14 and H34 multiplets were discussed. Spectroscopic parameters related to the laser operation at around 1.9 μm via the F34→H36 transition have been evaluated. Room-temperature quasi-cw 1.9 μm laser emission from a Ti:sapphire laser pumped Tm3+:NaLa(MoO4)2 crystal has been demonstrated. The maximum output power of 0.5 W has been achieved with a slope efficiency of 50%.

Detailed polarized spectral properties of Tm3+ : NaGd(MoO4)2 crystal have been investigated. The room temperature absorption and fluorescence spectra were recorded. The fluorescence decay mechanisms of the 1G4 and 3H4 multiplets in Tm3+ : NaGd(MoO4)2 crystal were discussed. Room temperature quasi-cw 1.9 µm laser emission from the Ti : sapphire laser pumped Tm3+ : NaGd(MoO4)2 crystal has been demonstrated. The maximum output power of 170 mW has been achieved with a slope efficiency of 25%.