Picosecond mid-infrared optical parametric amplifier based on LiInSe₂ with tenability extending from 3.6 to 4.8 μm

A picosecond (ps) mid-infrared (MIR) optical parametric amplifier (OPA) with LiInSe₂ crystal was demonstrated for the first time. The MIR OPA was pumped by a 30 ps 1064 nm Nd:YAG laser and injected by a barium boron oxide (BBO)-based widely tunable near-infrared seed. A maximum idler pulse energy of 433 μJ at 4 μm has been obtained under a pump energy of 17 mJ, and the corresponding pulse duration was estimated to be ~13 ps. To our knowledge, this is the highest single pulse energy generated by LiInSe₂ crystal. Furthermore, an idler spectrum tuning from 3.6 to 4.8 μm was investigated at fixed pump energy of 15 mJ.