The nonlinear absorption properties of TaSe₂ and its application in ~ 2.0 µm pulsed solid-state lasers

Enhancing the performance of saturable absorbers (SAs) crafted from two-dimensional (2D) narrow-bandgap materials is crucial for their use in ~ 2.0 µm pulse laser applications. In this context, a high-quality TaSe₂ SA was successfully fabricated by mechanical exfoliation. The TaSe₂ SA exhibited saturable absorption characteristics at around 2.0 μm, with a modulation depth of 7.1% and an unsaturated loss of 3.1%. Utilizing this newly fabricated SA, a passively Q-switched Tm:YAP laser operating near 2.0 μm was achieved. At the highest absorbed pump power of 5.58 W, the laser produced a maximum average output power of 1.34 W, with a pulse width measuring 550 ns at 89 kHz. This performance translates to a peak single pulse energy of 15.0 μJ and a maximum peak power of 27.27 W.