Distributed Bragg reflector effect in second harmonic generation in nonlinear superlattices

Abstract We investigate second harmonic generation (SHG) in one-dimensional nonlinear photonic crystal (NPC) superlattices sandwiched between high-reflectance distributed Bragg reflectors (DBRs). The NPC structures exhibit periodic modulation in both linear and quadratic susceptibility. In this paper, we exploit three mechanisms, namely, the quasi-phase matching (QPM) effect, the slow-light effect at the photonic band edges, and the cavity effect induced by the DBR mirrors, to enhance SHG. By choosing appropriate structural parameters, we can increase the SHG conversion efficiency by up to seven orders of magnitude in these structures compared to NPC structures operating solely on QPM.