Passive Q-Switched Operation of Tm:YAP Laser with Graphene/WS2 Heterostructure Saturable Absorber

Abstract

We use a graphene/WS₂ heterojunction as a saturable absorber (SA) in a 2 μm wavelength Thulium-doped Yttrium Aluminum perovskite (Tm:YAP) crystal-based solid-state laser and realize effective modulation performance efficiency in passive Q-switching experiments. At a pump power of 18.80 W, the measured output power is 1.293 W, with a corresponding optical–optical conversion efficiency of 6.9%. Additionally, at a pump power of 11.50 W, we achieve a pulse time of 1.16 μs at a repetition frequency of 90.36 kHz. To the best of our knowledge, this is the first demonstration of the use of graphene/WS₂ heterojunctions as SA structures for 2 μm solid-state lasers based on Tm:YAP crystals.