Multi-wavelength and broadly tunable repetition rate Tm:YAP self-Q-switch laser with high power output

Abstract

A high-power multicolor self-Q-switched laser emitting near 2 μm is demonstrated. Using the Tm:YAP crystal itself as the Q-switching element, the pulsed laser can achieve the highest average output power of 5.2 W ever reported to our knowledge, a pulse width of 0.52 μs, a slope efficiency of 47.3%, and a broadly tunable repetition rate of 22–143 kHz. Such performance is confirmed by a theoretical analysis involving thermal effects and saturable ground state re-absorption (GSRA). Additionally, the laser is capable of multi-wavelength output, including 1966, 1983.6, 1988.7 and 1991.6 nm, by using different output powers and transmittances. This scheme can effectively simplify the structure of laser resonator, and further promote the miniaturization of related devices at the 2 μm region.