Optical second harmonic generation properties of BiB3O6.

We present studies of the optical properties of the new nonlinear material BiB3O6 for second harmonic generation from the visible to infrared. We have determined the phase-matching conditions and effective nonlinear coefficients in the three principal optical planes, acceptance bandwidths, spatial and temporal walkoff, group velocity dispersion and double phase-matching behaviour. We also report on experimental studies in this material, where efficient, high-average-power second harmonic generation of femtosecond pulses into the blue is demonstrated. Using 130-fs fundamental pulses at 76 MHz, single-pass second harmonic average powers as much as 830 mW at greater than 50% conversion efficiency have been generated over a tunable range of 375-435 nm. Using cross-correlation measurements in a 100-mum beta-BaB2O4 crystal second harmonic pulse durations of 220 fs are obtained. Our theoretical findings are verified by experimental data, where excellent agreement between the calculations and measurements is obtained. Direct comparison of BiB3O6 with beta-BaB2O4 also confirms improved performance of this new material for second harmonic generation of femtosecond pulses.