QUASI-PHASE-MATCHED 1.064-MU-M-PUMPED OPTICAL PARAMETRIC OSCILLATOR IN BULK PERIODICALLY POLED LINBO3

We report a quasi-phase-matched optical parametric oscillator, using bulk periodically poled LiNbO3. The optical parametric oscillator, pumped by a 1.064-mum Q-switched Nd:YAG laser, was temperature tuned over the wavelength range 1.66-2.95 mum. The oscillation threshold of almost-equal-to 0.1 mJ was more than a factor of 10 below the damage limit. The LiNbO3 crystal, fabricated by application of an electric field to a sample with liquid and metal surface electrodes, was 0.5 mm thick with a 5.2-mm interaction length and a quasi-phase-matched period of 31 mum.