Peak-power of 25 W passively Q-switched ∼2.8 μm Er:YAP bulk laser based on a reflective TaSe2 saturable absorber mirror

Improving the overall performance of saturable absorber mirrors (SAMs) based on Two-dimensional (2D) narrow-band-gap materials is critically important in their applications of mid-infrared pulse laser sources. Herein, a reflective TaSe2 SAM with laser-induced damage threshold of ∼12 MW/cm2 was successfully fabricated, the saturable absorption properties around 2.8 μm were characterized with a modulation depth of 5.3% and a total unsaturated loss of 2.2%. With the as-prepared SAM, high-peak-power passively Q-switched Er:YAP laser operation at ∼2.8 μm was realized. For the condition of the maximum absorbed pump power of 8.0 W, the maximum average output power of 0.7 W was obtained with a pulse width of 264 ns at a repetition rate of 105.5 kHz, which corresponds to a maximum single pulse energy of 6.6 μ J and a peak power of 25.1 W.