Enhancement of second harmonic generation due to quasi-phase matching condition in a GaN-based one-dimensional photonic crystal

This paper reports measurements of the the giant second harmonic generation (SHG) enhancement of a 1D thin-film GaN-based photonic structure. The extraordinary enhancement has been obtained in specular reflection when the angular configuration satisfies the quasi-phase-matching (QPM) conditions, i.e. when both the fundamental and SH fields are resonant with radiative Bloch modes.