High-efficiency continuous-wave and LGS electro-optically Q-switched Tm: LuAG laser in-band pumped at 1623 nm

Abstract

We present a high-efficiency continuous-wave and LGS electro-optically Q-switched Tm:LuAG laser for the first time in this paper. The in-band pumping structure was realized by using a MgO:PPLN optical parametric oscillator at 1623 nm as the pump source. Under high-efficiency CW regime, a maximum output power of 10.8 W at 2023 nm was obtained under an incident pump power of 19.2 W, corresponding to a slope efficiency of 60.5 % and an optical-to-optical efficiency of 56.3 %. In addition, with 90/10 knife-edge method, the M²-factors in the x- and y-directions were measured to be about 1.3 and 1.2 at maximum output power, respectively. Under the EO Q-switching regime, a maximum average output power of 5.62 W was achieved under an incident pump power of 19.2 W and a repetition rate of 3000 Hz, corresponding to a slope efficiency of 34.2 %. With a repetition rate of 500 Hz, a maximum pulse energy of 8.14 mJ and a minimum pulse width of 32 ns were achieved with an incident pump power of 19.2 W, corresponding to a maximum calculated peak power of 254 kW.