External-cavity frequency doubler from 858 to 429 nm using KNbO3 crystal

Second harmonic generation from 858nm to 429nm has been investigated at room temperature by using Potassium Niobate (KNbO3) crystal. The optimum parameters for nonlinear conversion in our designing singly resonant, external ring cavity pumped by the Ti: Sapphire laser are established. In addition, we investigate the conversion efficiency over a range of operating conditions. When the cavity is scanned, 170 mW (235mW corrected for losses of the output mirrors) of blue light at 429nm is produced with 600mW of pump power near 858 nm whereas 137 mW is generated with 565 mW of pump when the cavity is locked.