Highly efficient blue light generation in KTiOPO4 waveguides

Abstract
Very high normalized efficiency, up to 800% W−1 cm−2 for infrared to blue light conversion (425 nm), has been obtained in quasi‐phase‐matched waveguides in KTiOPO4. It is shown by a detailed calculation that this value is higher by a factor of 4 than that predicted by theory.