High-energy, high-peak-power diode-pumped Q-switched Tm:YAG laser at 2.02 μm with tunable repetition rate from 100 Hz to 1000 Hz

Abstract A high-energy, high-peak-power Q-switched Tm:YAG laser at 2.02 μ m with a tunable repetition rate from 100 Hz to 1000 Hz and pulse duration in the hundreds of nanoseconds is demonstrated. The high energy output was achieved by employing a thermally stable linear cavity, including two compact laser diode continuous-wave side-pumped Tm:YAG laser modules. For Q-switched operation, stable Q-switched performance from 100 Hz to 1000 Hz was realized at near-room temperature. At a repetition rate of 100 Hz, the laser delivered a maximum pulse energy of 215 mJ with a pulse duration of 124.4 ns, resulting in a peak power of up to 1.73 MW. When the repetition rate was tuned to 200 Hz, 500 Hz, and 1000 Hz, pulse energies of 212 mJ, 125.6 mJ, and 68.2 mJ were obtained, with pulse durations of 133.6 ns, 176.3 ns, and 262 ns, respectively. To the best of our knowledge, these results represent the highest single pulse energies and peak powers ever accomplished for a diode-pumped Q-switched Tm-doped 2 μ m laser operating at high repetition rates exceeding 100 Hz.