Compact low-threshold Q-switched intracavity optical parametric oscillator

We report a singly resonant pulsed intracavity KTiOPO4 optical parametric oscillator that uses a semi-monolithic microchip laser design. The compact (50-mm-long), low-threshold (1.3-W) cavity uses a novel quadrupole deflector Q switch to give 4-mu J pulses at 1.064 mu m and 0.4-mu J signal pulses of 5.6-ns duration at 1.53 mu m with a repetition frequency of 5 kHz when it is pumped with a 2-W laser diode. The signal pulses are diffraction limited and single frequency. (C) 1998 Optical Society of America.