Fourier-transform-limited, high-power picosecond optical parametric oscillator based on periodically poled lithium niobate

We report on an optical parametric oscillator (OPO) based on periodically p oled lithium niobate (PPLN) synchronously pumped by a cw mode-locked picose cond Nd:YLF laser. High average output powers for the signal and idler radi ation of 2.55 W and 2.4W, respectively, have been achieved. The tuning rang e of the PPLN OPO is 1765-2060 nm for the signal radiation and 2155-2610nm for the idler radiation, limited by the chosen set of mirrors. The OPO sign al pulses are approximately bandwidth limited with a pulse duration of 45 p s and a spectral width of 0.35 cm(-1). As an application of this OPO we gen erate tunable mid-infrared radiation in the wavelength range of 9.8-19.4 mu m by difference-frequency mixing (DFM) of the OPO signal and idler radiati on in a CdSe crystal.