Efficient acousto-optically Q-switched Tm: LuAG laser end-pumped by a laser diode at 1.7 μm

We reported an efficient continuous-wave (CW) and acousto-optically (AO) Q-switched Tm: LuAG laser at 2 mu m in-band pumped by a 1.7-mu m laser diode for the first time. A maximum CW output power of 7.26 W at 2013 nm was achieved with an incident pump power of 28.2 W, corresponding to a slope efficiency of 38.5% and optical efficiency of 25.6%. With a repetition rate of 1 kHz, a maximum pulse energy of 5.63 mJ and a minimum pulse width of 77 ns were achieved under AO Q-switching regime, corresponding to a calculating peak power of 73.1 kW. Moreover, the M2-factors in x- and y-directions were measured to be about 1.9 and 1.7 at maximum output power, respectively.