A narrow-bandwidth optical parametric oscillator

A narrow-bandwidth, singly resonant, picosecond optical parametric oscillator based on a non-critical phase-matched lithium triborate crystal and synchronously pumped by the second-harmonic of a Nd:YLF laser mode-locked at 76 MHz is described. An intracavity birefringent filter reduces the spectral bandwidth and allows fast scanning of the output wavelength within the phase-matched bandwidth. A signal output of 1.6 W in Fourier transform limited pulses with a duration of 22 ps and a bandwidth of 0.06 nm has been obtained. The signal and idler wavelengths were tunable from 750 to 930 nm and from 1220 to 1770 nm, respectively.