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Utilizing the saturable absorption characteristics of transition metal dichalcogenides (TMDs), a passively Q-switched 1066 nm laser based on a novel Nd:GdYNbO4 mixed crystal as well as a two-dimensional (2D) layered molybdenum disulfide (MoS2) and tungsten disulfide (WS2) was realized for the first time. The highest repetition rate, the shortest pulse width and maximum peak power were 172 kHz, 723 ns and 0.85 W for Nd:GdYNbO4/WS2 laser, respectively. The corresponding values for the Nd:GdYNbO4/MoS2 laser were 122 kHz, 532 ns and 1.63 W. Furthermore, it was found that WS2 required a lower excitation energy, while a MoS2 nanosheet exhibits a deeper modulation depth.

The diode-end-pumped continuous-wave (CW) properties of Nd:Gd0.69Y0.3NbO4 laser were investigated and optimized. By optimizing the parameters of the laser, the output power had been improved. With the 320 μm waist radius of pump beam, 40 mm length of the laser resonator, 5% transmission of output coupler and 6.13 W absorbed pump power, the maximum value of the laser output power was 2.76 W and the slope efficiency was 51.2%. The optical quality images of laser beam were also shot and presented, when the parameters of the laser were in the best condition.

A diode-pumped MoS2 passively Q-switched Nd:Gd0.69Y0.3NbO4 laser at 1066 nm was demonstrated for the first time. The maximum continuous (CW) wave output power of 1.77 W was obtained when the absorbed pump power was 7.28 W and the transmission of flat output coupler was 25%. The maximum slope efficiency reached 33.3%. The pulsed laser with high repetition rate was obtained when the two-dimensional (2D) MoS2 material was used as the saturable absorber. The highest repetition rate and the narrowest pulse width were reached 112 kHz and 532 ns, respectively.

A diode-pumped MoS2 passively Q-switched Nd:Gd0.69Y0.3NbO4 laser at 1066 nm was demonstrated. The maximum value of pulsed peak power was 1.63W with the pulse duration of 532 ns and the repetition rate of 122 kHz.

A comparison of the pulsed laser performances of 2 μm passively Q-switched Tm:YAlO3 (YAP) lasers based on the use of tungsten disulfide (WS2) and molybdenum disulfide (MoS2) two-dimensional (2D) nanosheets as saturable absorbers is reported. The novel nanosheets were prepared by chemical vapor deposition (CVD) technology. The microstructure and optical characteristics of the nanosheets were investigated experimentally. In a continuous-wave (CW) operation, the maximum output power of 2.8 W was obtained at an absorbed pump power of 6.9 W, with a corresponding slope efficiency of 46.4%. In a passively Q-switched operation at a pump power of 1.45 W, the average output power, pulse width, repetition rate, pulse energy, and peak power for the Tm:YAP/WS2 laser were 0.11 W, 2.65 μs, 34.7 kHz, 2.9 μJ, and 1.23 W, respectively. As for the Tm:YAP/MoS2 laser, the corresponding values were 0.10 W, 2.5 μs, 24.0 kHz, 3.8 μJ, and 1.55 W.

In this paper, a passively Q-switched Tm:YAP laser with two-dimensional (2D) tin diselenide (SnSe2) nanosheet prepared by chemical vapor deposition (CVD) method as SA was demonstrated for the first time. The microstructure and optical characteristics of SnSe2 nanosheet were investigated to characterize it. Continuous-wave (CW) Tm:YAP laser was demonstrated firstly. The 6.9 W absorbed pump power was used to generate 2.36 W maximum output power with corresponding slop efficiency of 45.9%. The beam profiles and quality factor were measured, respectively. By inserting the SnSe2 into the plano-concave resonant, a Q-switched Tm:YAP laser operation at 2 µm was realized. The Q-switched laser had a maximum average output power of 411 mW, a shortest pulse duration of 2.4 µs, a maximum pulse repetition frequency of 43.2 kHz, a maximum pulse energy of 9.51 μJ and a highest peak power of 3.96 W.