Two-dimensional tin diselenide as the saturable absorber for passively Q-switched Er:YAP 3 μm solid-state laser

Abstract A passively Q-switched (PQS) Er:YAP laser at ∼3 μ m with the two-dimensional saturable absorber (SA) tin diselenide (SnSe 2 ) nanosheet as SA was successfully demonstrated for the first time. Under the maximum absorbed pump power of 4.0 W, the obtained continuous-wave maximum output power of Er:YAP laser was 258 mW with a corresponding slop efficiency of 7.18%. In the PQS experiment, laser pulses with the shortest pulse duration of 198 ns were yielded with a repetition rate of 317 kHz under the maximum absorbed pump power of 4.0 W, and the corresponding single pulse energy and pulse peak power were 0.66 µ J and 3.3 W, respectively. The investigation indicates that SnSe 2 has the potential to be an outstanding laser modulator for PQS solid-state laser at 3 μ m wavelength.