High-power blue light generation by external frequency doubling of an optical parametric oscillator

We report on an all-solid-state high-power quasi-continuous blue light source by the frequency doubling of a signal wave from an optical parametric oscillator (OPO). A 50-mm-long LiB3O5 (LBO) crystal is used for the OPO, which is pumped by a diode-pumped Nd:YAG green laser (10?kHz, 50?ns). Tunable blue emission in a new nonlinear crystal BiB3O6 (BiBO) is obtained with a wavelength range from 450 to 495?nm. The average power of the signal output is as high as 9.3?W from 924 to 970?nm. The maximum output of the blue laser with the second harmonic walk-off compensation is 1.3?W average power at 470?nm for 6.2?W of OPO signal light at 940?nm.