NbSe2/PtTe2 heterostructures as saturable absorbers for mid-infrared pulsed solid-state lasers

We have realized for the first time, to the best of our knowledge, a 2 µm nanosecond solid-state passive Q-switched Tm:YAP laser based on a NbSe2/PtTe2 heterojunction saturable absorber. At an incident pump power of 12.69 W, the Tm:YAP laser produces stable laser pulses with a minimum pulse width of 818 ns, a maximum single-pulse energy of 15.48 µJ, and a peak power of 18.93 W at a repetition rate of 79.44 kHz. The comparison results show enhanced saturable absorption performance compared to single NbSe2 (1 µs, 70.32 kHz) and single PtTe2 (1.31 µs, 71.97 kHz). The experimental results confirm that the NbSe2/PtTe2 heterojunction is a promising saturable absorption material that can be used to realize high-performance mid-infrared pulsed lasers. The resulting nanosecond 2 µm Q-switched pulsed laser will play an important role in atmospheric monitoring, lidar, and other fields, and can provide a strong driving force.