Passive Q-switching of an Yb:KLu(WO4)2 laser with 2D saturable absorbers of MoS2 and WS2: Scaling the output power to 2-W level

Abstract We report on a highly efficient, compact, passively Q-switched Yb:KLu(WO 4 ) 2 laser, with few-layer MoS 2 or WS 2 acting as saturable absorber. A maximum output power of 2.45 W was generated at a repetition rate of 2.52 MHz, with 6.49 W of pump power absorbed in passively Q-switched operation induced by MoS 2 ; the largest pulse energy, shortest duration, and highest peak power were, respectively, 1.27 μ J, 43 ns, and 29.5 W. With WS 2 as saturable absorber, the output power attainable in stable Q-switched operation was 1.87 W, produced with an optical-to-optical efficiency of 37% and a slope efficiency of 71%. The minimum pulse duration obtained was 39 ns; while the largest pulse energy and highest peak power were 1.19 μ J and 30.5 W.