100 Hz, 39.6 mJ compact linear polarization Q-switched Ho:YLF oscillator

High-energy linearly polarized Q-switched lasers are realized using a 1940 nm Tm-doped fiber laser to in-band pump a compact U-type Ho:YLF oscillator. When absorbing 44 W pump power, the laser output power under continuous-wave (cw) operation is 9.7 W, and the center laser wavelength is 2051.7 nm. Corresponding to 22% optical-to-optical conversion efficiency and up to 77.9% slope efficiency. The Q-switched Ho:YLF oscillator has a maximum single pulse energy of 39.6 mJ under a repetition rates of 100 Hz and absorption of 42.4 W pumping, and the pulsewidth is 47 ns. The beam quality M2 factors in the horizontal and vertical directions are 1.17 and 1.07, respectively.