WS 2 Passively Q-switched Er:SrF 2 Laser at ~3 µ m

Abstract A few-layer tungsten disulfide (WS 2 ) nanosheet film on a YAG substrate was fabricated and used as saturable absorber in a passively Q-switched Er:SrF 2 laser operating at 2.79 µ m. Under an absorbed power of 2.42 W, a stable Q-switched laser operation was realized with an average output power of 428 mW and a pulse duration of 679 ns at a repetition rate of 38 kHz, corresponding to a pulse energy of 11.26 µ J.