KILOHERTZ AGGASE2 OPTICAL PARAMETRIC OSCILLATOR PUMPED AT 2 MU-M

A high-repetition-rate high-average-power AgGaSe2 doubly resonant opti cal parametric oscillator has been demonstrated by using a 2-mum pump laser operating at 2.5 and 5 kHz. Energy conversion and slope efficien cies of 23% and 32%, respectively, were achieved. Sustained average po wer outputs as high as 740 mW were measured. Evidence of optical param etric oscillator output saturation and damage site formation at the cr ystal output face are effects attributed to thermal lensing in our AgG aSe2 crystal.