Intracavity difference-frequency mixing of OPO signal and idler pulses in BaGa 4 Se 7

An overall quantum conversion efficiency of 7.8% is achieved by intracavity mixing the signal and idler of a 1.064-μm pumped Rb:PPKTP OPO in BaGa 4 Se 7 , generating >0.7 mJ pulse energy at ∼7 μm and 100 Hz.