90° Phase-matched difference-frequency generation at 5.34–7.48 μm in BaGa 4 S 7

By pumping the 1.4 cm long θ=9.2° and φ=0° cut BaGa 4 S 7 crystal oriented for the 90° phase-matching conditions along the z(=b) axis with the Quanta Ray GLR-20 Nd:YAG laser incorporating the BBO/OPO and by changing the crystal temperature from 25 °C to 180 °C, we have generated the tunable mid-IR pulses in the 5.341-7.477 μm range.