Tunable 7-12 μm picosecond optical parametric amplifier based on a LiInSe2 mid-infrared crystal

Mid-infrared (MIR) nonlinear optical crystals of LiInSe2 (LISe) were grown by a modified Bridgman technique on a (001)-seed. A 7 - 12 mu m widely tunable picosecond (ps) MIR optical parametric amplifier (OPA) based on a LISe crystal was demonstrated for the first time, to the best of our knowledge. The MIR OPA was pumped by a 30 ps 1064 nm Nd: YAG laser and injected by a KTiOPO4 (KTP)-based widely tunable near-infrared seed. The idler operating at 7.5 mu m with the highest pulse energy of 170 J was obtained under a pump energy of 14 mJ. The corresponding energy conversion efficiency is similar to 1.21%, and the photon conversion efficiency is 8.6%. The output energies were measured to be similar to 121 mu J at 7 mu m and similar to 21 mu J at 12 mu m. (C) 2017 Optical Society of America