FREQUENCY UP-CONVERSION BY PHASE-MATCHED SUM-FREQUENCY GENERATION IN AN OPTICAL PARAMETRIC OSCILLATOR

We report the generation of 0.589-mu m radiation from mixing the pump at 1.064 mu m and the signal at 1.319 mu m of a singly resonant, synch ronously pumped AgGaS2 optical parametric oscillator. A KTP crystal is used for the sum-frequency generation (SFG). Both extracavity and int racavity SFG is demonstrated, with overall conversion efficiencies of 3.5% and 10.5%, respectively. Near-transform-limited pulses of less th an 50 ps are generated from 100-ps pulses. With a limited available pe ak pump power, both spatial orderings of the KTP and the AgGaS2 crysta ls for intracavity SFG produce similar conversion efficiency and outpu ts of similar pulse duration, spectral width, and stability.