Low index contrast heterostructure photonic crystal cavities with high quality factors and vertical radiation coupling

摘要

We report here design and experimental demonstration of heterostructure photonic crystal cavities resonating near the Gamma point with simultaneous strong lateral confinement and highly directional vertical radiation patterns. The lateral confinement is provided by a mode gap originating from a gradual modulation of the hole radii. High quality factor resonance is realized with a low index contrast between silicon nitride and quartz. The near surface-normal directional emission is preserved when the size of the core region is scaled down. The influence of the cavity size parameters on the resonant modes is also investigated theoretically and experimentally. Published by AIP Publishing.