Few-layered ReS2 as saturable absorber for 2.8 μm solid state laser.

Abstract

A novel two-dimensional (2D) material member in the transition metal dichalcogenides family, few-layered rhenium disulfide (ReS2) was prepared by liquid phase method successfully. By using the open-aperture Z-scan method, the saturable absorption properties at 2.8μm were characterized with a saturable fluence of 22.6 μJ/cm2 and a modulation depth of 9.7%. A passively Q-switched solid-state laser at 2.8μm was demonstrated by using the as-prepared ReS2 saturable absorber successfully. Under an absorbed pump power of 920mW, a maximum output power of 104mW was obtained with a pulse width of 324ns and a repetition rate of 126kHz. To the best of our knowledge, this is the first demonstration of applying ReS2 in an all-solid-state laser. Moreover, this represents the shortest pulses in Q-switched MIR lasers based on a 2D material as the saturable absorber, which demonstrated the superiority of ReS2 acting as an optical modulator for generating short-pulsed lasers. The results well prove that 2D ReS2 is a reliable optical modulator for MIR solid-state lasers.