Strong Optical Confinement between Non-periodic Flat Dielectric Gratings

TL;DR

This paper introduces a novel planar optical micro-cavity design that confines light strongly in free space, enabling easy integration and accessibility for applications involving atoms, molecules, or mechanical resonators.

Contribution

The authors propose a new design method for optical micro-cavities with high quality factors and diffraction-limited mode volumes, using stochastic optimization techniques.

Findings

Cavity designs achieve quality factors between 10^4 and 10^6.

Mode volumes are diffraction-limited.

Designs are compatible with standard on-chip fabrication.

Abstract

We present a novel design of optical micro-cavity where the optical energy resides primarily in free space, therefore is readily accessible to foreign objects such as atoms, molecules, mechanical resonators, etc. We describe the physics of these resonators, and propose a design method based on stochastic optimization. Cavity designs with diffraction-limited mode volumes and quality factors in the range of $10^4$--$10^6$ are presented. With a purely planar geometry, the cavity can be easily integrated on-chip using conventional micro- and nano- fabrication processes.