High-Power Continuous-Wave and Acousto-Optical Q-Switched Ho:(Sc_0.5Y_0.5)_2SiO_5 Laser Pumped by Laser Diode

We experimentally investigate the continuous-wave (cw) and acousto-optical (AO) Q-switched performance of a diode-pumped Ho:(Sc_0.5Y_0.5)_2SiO_5 (Ho:SYSO) laser. A fiber-coupled laser diode at 1.91 μm is employed as the pump source. The cw Ho:SYSO laser produces 13.0 W output power at 2097.9 nm and 56.0% slope efficiency with respect to the absorbed pump power. In the AO Q-switched regime, at a pulse repetition frequency of 5 kHz, the Ho:SYSO laser yields 2.1 mJ pulse energy and 21 ns pulse width, resulting in a calculated peak power of 100 kW. In addition, at the maximum output level, the beam quality factor of the Q-switched Ho:SYSO laser is measured to be about 1.6.