High-energy MIR picosecond optical parametric amplifier with ultra-wide tunability spanning from 3 to 14 µm based on...

We report the first demonstration of an ultra-wide tunable MIR optical parametric amplifier (OPA) based on a new nonlinear crystal, BaHgGeSe₄ (BHGSe). Pumped by a picosecond (ps) 1.064 µm laser, the OPA achieves an unprecedented idler tuning range of 3-14 µm, with pulse energies of 176 µJ at 7.3 µm and 143 µJ at 11.8 µm, and pump to idler conversion efficiency of 2.15 and 1.74%, respectively. The results indicate that the new BHGSe crystal can be an excellent candidate for ultra-wide tuning MIR radiation generation under 1.064 µm laser pumping.