SINGLE-FREQUENCY OPTICAL PARAMETRIC OSCILLATOR

An optical parametric oscillator operating on a single longitudinal mode of its resonator is described. Using KTP as the nonlinear optical material and a grazing-incidence-grating resonator, single-frequency linewidths of 0.02 cm-1 are achieved. The device, pumped at 532 nm, was tuned over 0.7-0.9-mu-m (signal branch) and 1.3-2.2-mu-m (idler branch), and operated with up to 3 mJ of output corresponding to an external photon conversion efficiency of 12%.