Development of a two-wavelength OPO generating 270-mJ infrared pulses for medical applications

An optical parametric oscillator (OPO) pumped by a pulsed LD-pumped Nd:YAG laser that simultaneously emits two infrared radiation in 1.7 and 3 /spl mu/m regions is developed. In order to efficiently perform on the wavelength mixing, a periodically poled lithium niobate (PPLN) in the OPO resonator is employed. The total output energy obtained was 270 mJ consisting of 120 mJ in the 3 /spl mu/m region and 150 mJ in the 1.7 /spl mu/m region at a repetition rate of 40 Hz and a pulse duration of 500 /spl mu/s.