Dual-wavelength paired-pulse Tm:YAlO₃/Ho:LuLiF₄ laser at 1944 and 2066 nm

The dual-wavelength paired-pulse output of a compact self- Q -switched T m : Y A l O 3 intra-cavity pumping H o : L u L i F 4 laser was first demonstrated experimentally. By exploiting the self- Q -switching mechanism of T m : Y A l O 3 and the gain-switching operation of H o : L u L i F 4 in a cavity, the dual-wavelength paired pulses were robustly generated with the pulse energy of 29 µJ, pulse width of 2.5 µs at 1944 nm, pulse energy of 31 µJ, and pulse width of 338 ns at 2066 nm. The maximum average output powers were obtained simultaneously as high as 525 mW at 1944 nm and 323 mW at 2066 nm. The paired-pulse repetition frequency can be pump-tunable in the range of 8–22 kHz. The temporal delay in the paired pulses can be controllable from 9.5 to 2.9 µs with the pump power increasing from 15.2 to 18.4 W. The compact dual-wavelength paired-pulse laser near 2 µm has potential application in the differential absorption lidar.