High-power, high-repetition-rate picosecond optical parametric oscillators for the near-to mid-infrared

We report high-repetition-rate, singly-resonant, picosecond optical parametric oscillators based on the nonlinear crystals LiB3O5 and KTiOAsO4 which are synchronously pumped by a self-mode-locked Ti:sapphire laser operating at 81 MHz. These devices allow tunable pulse generation from 1·116-3·160 μm to be achieved. The LiB3O5 system produces average nearinfrared output powers of 325 mW and is continuous tuning over the wavelength range 1·16-2·26 μm. For 1·8 ps input pump pulses, transform-limited signal pulses with durations of 1-1·2 ps and idler pulses with durations of 2-2·2 ps have been generated over 1·2-2·2 μm, without requirement for dispersion compensation. The KTiOAsO4 system produces average near-infrared output powers of 403 mW, with the signal tuning over 1·116-1·281 μm and idler tuning over 2·260-3·160 μm. Without dispersion compensation, signal (idler) pulses with durations between 1·01-1·03 (1·61-2·91) ps have been obtained for 1·2 ps input pump pulses.