Resonantly pumped high efficiency Ho:GdTaO4 laser

We demonstrate a continuous-wave 2.1-µm laser with a new Ho:GdTaO4 crystal pumped by a 1940.3-nm Tm fiber laser at room temperature. The maximum output power of 11.2 W at 2068.39 nm was achieved, corresponding to a slope efficiency of 72.9%. Moreover, the beam quality factor was measured to be about 1.4 at the maximum output level.