Picosecond near- to mid-infrared optical parametric oscillator using KTiOAsO4

The operation and characterization of a high-repetition-rate singly-resonant picosecond optical parametric oscillator based on the non-linear material KTiOAsO4 and synchronously pumped by a Kerr-lens-mode-locked Ti:sapphire laser at 81 MHz is described. By utilizing non-critical type II phase-matching in a 10 mm crystal, average near-infrared output powers of 403 mW have been generated at 31% extraction efficiency. The oscillator exhibits a pump power threshold of 230 mW and with the available mirror set can provide signal tuning over 1.116-1.281 mu m and idler tuning over 2.260-3.160 by mu m tuning the pump wavelength over 770-896 nm. Without dispersion compensation, near-transform-limited signal pulses with durations of 1.01-1.03 ps and idler pulses with 1.61-2.91 ps duration have been obtained for 1.2 ps input pump pulses.