Tunable 7-12-mu m optical parametric oscillator using a Cr,Er:YSGG laser to pump CdSe and ZnGeP2 crystals

A CdSe optical parametric oscillator (OPO) pumped by a 2.79-mu m, Cr,Er:YSGG laser yielded a 59% signal-plus-idler slope efficiency (eta), a total idler output of 1.2-2.4 mJ between 8.5 and 12.3 mu m, and an idler beam that was 2.2-2.5 times the diffraction limit. A ZnGeP2 OPO operated with a lower threshold, eta = 29%, and a forward idler output of 0.7-2.4 mJ from 6.9 to 9.9 mu m. The signal and idler bandwidths were typically 4 cm(-1) for each OPO. (C) 1997 Optical Society of America.