High-energy 1064-nm pumped optical parametric oscillator for the 6 µm spectral range based on HgGa2S4

The defect chalcopyrite crystal HgGa2S4 has been employed in a 1064-nm pumped optical parametric oscillator to generate <7 ns long idler pulses near 6.3 µm with energies as high as 3 mJ, tunable in a broad spectral range from 4.5 to 9 µm.