Tunable down-conversion from an optical parametric oscillator

A new method for the production of high power, tunable laser-like infrared radiation is described. An optical parametric oscillator (OPO) and a down-converter are combined so that radiation is generated at the frequency difference between signal and idler frequencies. In an experiment using proustite for the down-converter crystal and a 1.065µm pumped OPO, tunable radiation has been produced over the range 8-12µm. Using CdSe in the down-converter the region 10-25µm could be spanned with peak powers approaching 100W