Room temperature efficient actively Q-switched Ho:YAP laser.

We report on efficient actively Q-switched Ho:YAP laser double-pass pumped by a 1.91-microm laser. At room temperature, when the incident pump power was 20.9 W, a maximum average output power of 10.9 W at 2118 nm was obtained at the repetition rate of 10 kHz, and this corresponds to a conversion efficiency of 52.2% and a slope efficiency of 63.5%. Moreover, a maximum pulse energy of approximately 1.1 mJ and a minimum pulse width of 31 ns were achieved, with the peak power of 35.5 kW.