Blue LD pumped passively Q-switched Pr:YLF lasers generation using 2D germanene nanosheets

Abstract

Germanene, a two-dimensional analogue of graphene, possesses remarkable characteristics such as high carrier mobility and enhanced stability, which have catalyzed extensive research endeavors in recent years. However, the nonlinear optical properties of germanene, particularly within the visible spectrum, have been scarcely explored in existing research. In this work, germanene nanosheets were prepared via a liquid-phase exfoliation method, followed by characterization of the nonlinear optical properties utilizing dual-arm detection technology. The results indicate that the saturation intensity and modulation depth at a wavelength of 640 nm are approximately 1.39 MW/cm² and 12.83%, respectively. Leveraging these exceptional saturable absorption properties, we implemented germanene nanosheets as a saturable absorber in a Pr:YLF solid-state laser, achieving passively Q-switched signal output with a pulse width of 194.14 ns and a peak power of 1.89 W. The results substantiate the potential of germanene as a viable saturable absorber for applications in the visible light range.