A doubly resonant photonic-crystal microcavity for second-harmonic generation

A two-dimensional, photonic-crystal microavity is proposed in order to achieve efficient second-harmonic generation in the third opitical communication window. The simultaneous resonance conditions of the pump beam at the fundamental frequancy and second-harmonic field generated inside the stuucture with a defect provides a considerable enhancement of the conversion efficiency. In the configuration we propose, a transverse-mangnetic (TM) polarized beam resonating at the fundamental freequancy generates a second-harmonic field corresponding to a transverse-electric (TE) polarized resonant mode. The design of this doubly resonant microactivity is carried out by a linear analysis to search for the resonance frequancies and calculate their field distrubutions. The nonlinear analysis of the second-harmonic generation is performed using a dispersive finite-difference time-domain code.