Nonlinearity and application of alloyed TMDs materials MSSe (M = W, Mo)

Alloying significantly enhances the diversity of transition metal dichalcogenides (TMDs) and creates numerous opportunities for various applications of TMD materials. This study investigated the nonlinear optical properties of alloyed TMDs, specifically MSSe (M = W, Mo), and explored the potential of MSSe materials as modulation devices for use in Q-switched laser systems. We synthesized nanosheets of WSSe and MoSSe and conducted experimental measurements to determine the modulation depths for few-layer WSSe and MoSSe saturable absorbers (SAs), which were found to be 10.71% and 12.17%, respectively. Subsequently, the SAs based on WSSe and MoSSe were utilized in Tm:YAP passively Q-switched lasers. When employing an output coupling mirror with a transmittance of 5%, short modulation pulses 499.38 and 395.46 ns were attained at an output center wavelength of 1938nm, corresponding average output powers reaching up to 0.595 and 0.512 W, respectively. The results indicated that both materials exhibit high performance as SAs, thereby presenting promising opportunities for the development of advanced optoelectronic devices.