Recent advances in phase matching of second‐order nonlinearities in monolithic semiconductor waveguides

Abstract Techniques used to assist phase matching of second‐order nonlinearities in semiconductor waveguides are reviewed. The salient points of each method are highlighted, with their strengths and weaknesses with regard to various key applications discussed. Recent progress in these techniques is also reviewed. Emphasis is placed on two techniques, namely quasi‐phase matching via domain disordering utilizing quantum well intermixing, and exact phase matching using Bragg reflection waveguides.