Photonic crystal cavity embedded in electromagnetically induced transparencymedia

Abstract

Photonic crystal cavities are known for their high quality factor and small modal volume.Electromagnetically induced transparency (EIT) is known for its dramatic dispersion. Westudy the fundamental cavity mode of a two-dimensional photonic crystal embedded in anEIT medium. Comparison of finite-difference time-domain simulations with an analyticalintracavity-EIT model yields similar results: the modal density of the photonic crystalcavity increases and the cavity resonance is pulled from the empty cavity resonance to thetwo-photon resonance of the EIT medium. As a consequence, the quality factormay be enhanced by more than two orders of magnitude. For a miniature sized2.5λ × 2.5λ photonic crystalcavity based on a 5 × 5 high index rod structure with a missing centre rod, the quality factor can be increased from200 to 40 000.