Passively Q-switched Nd:GYAP laser at 1.3 μm with bismuthene nanosheets as a saturable absorber

Two-dimensional (2D) saturable absorbers (SAs) with air-stable have a promising application in laser pulse generation. Few-layer bismuth (Bi), as a novel 2D material, exhibits unique characteristics, such as high carrier mobility, great long-term stability, moderate bandgap and air stability, which has drawn increasing attention of researchers. In this work, few-layer bismuthene nanosheets were prepared and used for fabricating SA. Based on the synthesized bismuthene nanosheets SA, an all-solid-state passively Q-switched Nd:GYAP laser at 1.3 μm was realized for the first time. The shortest pulse width of 361 ns was obtained under the maximum absorbed pump power of 3.55 W, corresponding to the repetition rate of 365 kHz and the peak power of 1.52 W. Our result reveals that bismuthene nanosheets could be a promising SA for pulse laser generations in the near-infrared region.