High-power and high-efficiency diode-pumped Nd:LuYAG mixed crystal lasers operating at 939 and 946 nm

We report on high-performance infrared lasers at 0.94 mu m based on quasi-three-level transition of F-4(3/2) -> I-4(9/2) in Nd:LuYAG mixed crystal, for the first time to our knowledge. The maximum output power was achieved to 5.64 W with slope efficiency of approximately 52.5% at 946 nm. The simultaneous dual-wavelength laser at 939 and 946 nm is also obtained with maximum output power of 3.61 W and slope efficiency of 34.8% by introducing a glass etalon into the cavity. Moreover, a 2.0-W single-wavelength laser at 939 nm can be further attained by suitably tilting the etalon. Using a Cr:YAG saturable absorber, Q-switched laser operation is realized with maximum average output power of 0.68 W and the narrowest pulse width of 8.4 ns, which results in the maximum single pulse energy of approximately 55.3 mu J and the maximum pulse peak power of approximately 6.15 kW. Finally, thermal focal length of the laser crystal is estimated by using a flat-flat laser cavity. (C) 2016 Optical Society of America.