Highly-efficient cw blue light generation via first-order quasi-phase-matched frequency-doubling of a diode-pumped 946nm Nd:YAG laser

49 mW of cw blue light have been generated with a conversion efficiency of 4.6% by first-order quasi-phase-matched frequency doubling of a high-power diode-pumped 946 nm Nd:YAG laser. A sample of periodically poled LiNbO3, with domain reversal period of 4.6 µm and length of 6 mm was used in the experiment. The measured effective nonlinear coefficient of 19 pm/V and the bandwidth of 3 °C for the quasi-phase-matching curve (second harmonic power vs. temperature) are very close to the theoretical limits.