Double Fabry–Pérot etalons assistant injection-seeded single-frequency Tm,Ho:YLF laser

In this paper, we report a diode side-pumped injection-seeded single-frequency Tm,Ho:YLF laser, which operated at lasing threshold and emitted at 2051.2 nm. The assistance of Fabry–Pérot (FP) etalons to seed injection via mode selection was investigated. An acousto-optic Q-switched output of 6.7 mJ was achieved at 5 Hz. A temporal pulse duration of 310 ns with spectral linewidth of 2.0 MHz and frequency stability of 0.8 MHz root-mean-square (rms) was detected. The beam profile was a high-quality Gaussian TEM 00 mode with M 2 x/y of ~ 1.15/1.14. This 2 μm laser source would be a good candidate for ground-based wind-detection coherent Lidar system.