Two-dimensional WS2 nanosheet based passively Q-switched Nd:GdLaNbO4 laser

In this paper, we present a diode-pumped passively Q-switched laser based on a novel Nd:Gd0.89La0.1NbO4 mixed crystal and two-dimensional (2D) tungsten disulfide (WS2) saturable absorber. After the optimization of the laser parameters, a maximum continuous-wave (CW) output power of 4.37 W with a slope efficiency of 42% was obtained, which is the highest output power to the best of our knowledge. Utilizing the saturable absorption characteristic of the 2D WS2 material, the pulsed Nd:Gd0.89La0.1NbO4 laser performance was investigated. The shortest pulse duration of 895 ns and the highest repetition rate of 162 kHz were realized at an absorbed pump power of 7.18 W.