HIGH-EFFICIENCY 2ND-HARMONIC-GENERATION WITH A LOW-POWER DIODE-LASER

We demonstrate generation of 8 mW (10 mW corrected for the output mirr or reflection) of the cw coherent blue light around 430 nm by frequenc y doubling of only 20 mW from a diode laser. With IR power of 90 mW we reach the doubling efficiency of 60%. The overall conversion efficien cy from the electrical power into the blue light is 10%. By the way of careful analysis of the Blue Light Induced IR Absorption (BLIIRA) in the potassium niobate based external doubling cavity we obtain good ag reement with the theoretical conversion efficiency.