Highly efficient generation of blue-orange femtosecond pulses from intracavity-frequency-mixed optical parametric oscillator

The second harmonic generation of the signal or sum frequency generation of the signal and pump in a beta-BaB2O4 crystal in the cavity of an optical parametric oscillator pumped synchronously by a mode-locked Ti:sapphire laser is reported. Visible femtosecond pulses with an average power of 330 mW are generated with a pumping power of 1.3 W. Broad tunability is achieved from 426 to 483 nm and 520 to 585 nm using a single mirror set.