Femtosecond laser written waveguides with MoS_2 as satuable absorber for passively Q-switched lasing

Abstract

This work reports on the passively Q-switched waveguide laser system based on Nd:YAG crystal and MoS2 satuable absorber. A depressed cladding waveguide with circular cross-sectional geometry has been produced in Nd:YAG crystal by direct femtosecond laser writing at low-repetition rate. The confocal microscopic investigation of the structure reveals the well-preserved microphotoluminescence features in the waveguide core. With chemical-vapor-deposition (CVD) MoS2 membrane as satuable absorber, the passive Q-switching of the Nd:YAG waveguide system has been achieved under optical pump, reaching maximum average output power of 85.2 mW, corresponding to single-pulse energy of 112 nJ, at wavelength of 1064 nm. The repetition rate of the pulsed waveguide laser system is tunable from 0.51 to 1.10 MHz, and the obtained minimum pulse duration is 203 ns.