Mo0.5W0.5S2 as saturable absorber for passively mode-locked Tm:YAP laser

Abstract

In recent years, 2 μm pulsed lasers have received extensive attention from researchers due to their wide applications in materials processing and medical fields. In this work, we reported preparing Mo_0.5W_0.5S₂ saturable absorber (SA) via liquid phase exfoliation and successfully using this SA in Tm:YAP lasers to generate passively mode-locked (PML) pulses. An average output power of 0.87 W was achieved with the injected pump power of 20.38 W in the PML Tm:YAP laser, corresponding to a slope efficiency of 4.8%. Moreover, a pulse width of 686.4 ps at 85.9 MHz was acquired with a central output wavelength of 1935 nm from the laser, and the beam quality of M² was measured to be 1.10 and 1.12 in the X and Y directions. The potential of Mo_0.5W_0.5S₂ material in the transition metal dichalcogenides family for saturable absorption property in the 2 μm region was demonstrated by this work.