Diode-pumped passively Q-switched Nd:GdYTaO4 laser based on two-dimensional WS2 nanosheet

A diode laser pumped passively Q-switched Nd:Gd0.69Y0.3TaO4 laser based on two-dimensional (2D) layered tungsten disulfide (WS2) saturable absorber was demonstrated for the first time. In the continuous wave (CW) operation, the maximum output power of 5.24 W with slope efficiency of 41% was obtained when the absorbed pump power was 14.18 W. The pulsed Nd:Gd0.69Y0.3TaO4 laser was realized when the 2D material of WS2 saturable absorber was inserted into the cavity. The shortest pulse duration and the highest repetition rate were 640 ns and 231 kHz, respectively. It is believed that a better laser performance can be expected when the quality of 2D material of WS2 and Nd:Gd0.69Y0.3TaO4 mixed crystal is improved.