91.1 kW, 5.3 ns compact mid-infrared optical parametric amplification based on PPMgLN

•Compact mid-infrared optical parametric amplifier (OPA) based on PPMgLN.•High peak power and short pulse width of the OPA idler.•Good beam quality of the OPA idler due to the two stages structure. We report a compact mid-infrared optical parametric oscillator (OPO) seeded optical parametric amplifier (OPA) based on PPMgLN. The pump for the OPO and OPA is a split 1064 nm electro-optical Q-switched Nd:YAG laser with a pulse width of 11.7 ns and a pulse repetition frequency of 2 kHz. The idler power of 116 mW of the OPO is used for the OPA seed. Under the incident pump power of 7.36 W and the crystal temperature of 30 °C, the idler power of the OPA is 966 mW with a pulse width of 5.3 ns, corresponding to a conversion efficiency of 11.5% and a calculated peak power of 91.1 kW. The central wavelength of the OPA idler is 3731.2 nm with a linewidth of 8.8 nm at 30 °C, and decreased from 3748.8 nm to 3704.0 nm when the crystal is heated from 20 to 45 °C. The beam quality factors of the OPA are 3.4 and 3.7 in the horizontal and vertical directions, respectively.