Dispersion Engineering for a Metastructure Composed of a High‐Contrast Subwavelength Grating and a Distributed Bragg Reflector

Abstract

High-contrast subwavelength grating (HCG) and distributed Bragg reflector have been demonstrated to be able to tailor the dispersion independently. In this study, we find that multiple-shape dispersions can be realized by a metastructure which consists of an HCG on the distributed Bragg reflector. Such a simple structure exhibits the linear dispersions with band-edge modes, the M-shaped dispersion with a cavity mode, and the W-shaped dispersion with a bound state in the continuum. The origins of these dispersions and the mode characteristics (field distribution and quality factor) in the dispersions are studied. This study is helpful to realize single-mode high-efficiency surface-emitting lasers, optical sensors, and quantum electrodynamics.