41 kHz repetition rate passively Q-switched Ho:YAP laser with Cr:ZnS as a saturable absorber

We report a continuous wave Tm:YAP laser resonantly pumped Ho:YAP laser in CW mode and passive Q-switched mode. Multilayer Cr:ZnS is used as the saturable absorber for the Q-switched operation. The maximum continuous wave output power of 6.36 W at 2118.67 nm was obtained, corresponding to a slope efficiency of 25.2% and the overall optical-to-optical conversion efficiency of 19.8%. The maximum pulse repetition frequency reached 41.25 kHz and the minimum pulse width of 382 ns was obtained at average output power of 5.24 W. Meanwhile, the output beam spatial profile was close to fundamental TEM 00 mode and the beam quality factor M 2 was 1.4.