A ZnGeP2 (ZGP) optical parametric oscillator (OPO) is described that is pumped by a gain-switched Cr2+:ZnSe laser and which is broadly pump-tuned in the midinfrared. Both Type I and Type II ZGP OPOs operating in the 4 to 6 µm region are demonstrated with slope efficiencies as high as 53%. The Type II configuration is noncritically phase matched and can potentially tune from 3.4 to 6.1 µm by tuning the pump laser from 2.1 to 2.9 µm. The Type I configuration can either angle- or pump-tune over nearly the entire transparency range of ZGP.
© 2001 Optical Society of AmericaPDF Article