Femtosecond optical parametric oscillator based on periodically poled stoichiometric LiTaO3 crystal

Efficient optical parametric oscillation is demonstrated in periodically poled stoichiometric lithium tantalate crystal pumped by a mode-locked Ti:sapphire laser. The optical parametric oscillator (OPO) delivers a maximum average power of more than 345 mW in signal and 180 mW in idler beams. The OPO is continuously tunable across the 940-1350 nm wavelength range in its signal branch, delivering nearly transform-limited 160-180 fs pulses. Despite the onset of high absorption loss in the crystal in the mid-IR, more than 40 mW of power is obtained for the idler beam tunable within the 4.3-4.6 microm wavelength range. The high parametric gain in the crystal allows tunable OPO operation at a repetition rate as high as 760 MHz with 50 mW of output power.