High-efficiency 2 μm Tm:YAP laser with a compact mechanical Q-switch

We describe a compact, highly efficient, diode-pumped, mechanically Q-switched Tm:YAP laser operating near 2 mu m. The Q-switch, based on a torsion spring resonant mirror scanner, had negligible optical loss and required very low electrical drive power. At a 10 kHz pulse repetition frequency, the laser generated an average output power of 10.5 W at 1.94 mu m, Q-switched pulse energy of 1.05 mJ, a pulse length of 31 ns, and a peak power of 34 kW. The Q-switched laser exhibited maximum optical and electrical efficiencies of 51% and 26%, respectively.