Optical parametric oscillation with KTiOAsO4.

We present what is to our knowledge the first demonstration of a femtosecond optical parametric oscillator using the new nonlinear crystal KTiOAsO4 Powers of as much as 75 mW in the signal branch and as much as 100 mW in the idler branch were coupled out of the cavity. Pulse widths as short as 85 fs in the signal branch and 150 fs in the idler branch were measured. The potential of tuning out to ~5 μm in the idler branch is discussed.