Fully Open Ring Microcavities Based on Metagratings

Abstract

Open optical microcavities are crucial to precise manipulation of light–matter interaction in solid‐state and biological systems. However, only open linear microcavities are practically realized, limiting the application of open microcavities in more scenarios. Herein, an ease‐fabrication fully open ring microcavity is theoretically demonstrated that supports simultaneously multiple concentric cavity modes with coupling interaction. It comprises two orthogonal dielectric metagratings, which are a single layer of silicon rods and enable transmitted waves to travel in a negative angle. Except for fully open configuration, the open microcavity also incorporates the advantages of low absorption loss and the compatibility to the current CMOS process. It offers a unique platform for controlling the interaction between light and atoms, molecules, nanoparticles, or biomolecules and will find a broad range of applications.

Keywords

• dielectric metagratings
• dipole resonance states
• negative transmissions
• open microcavities