Continuous-wave laser operation of Tm and Ho co-doped NaY(WO 4 ) 2 and NaLu(WO 4 ) 2 crystals

Tetragonal single crystals of NaT(WO4)2 (T = Y or Lu) co-doped with Tm3+ and Ho3+ ions have been employed for broadly tunable and efficient room-temperature laser operation at around 2 μm. With Ti:sapphire laser pumping at 795 nm, a slope efficiency and a maximum output power as high as 48% and 265 mW, respectively, have been achieved at 2050 nm from a Tm,Ho:NaY(WO4)2 crystal. Tuning from 1830 nm to 2080 nm has also been obtained using an intracavity Lyot filter.