Creating a zero-order resonator using an optical surface transformation

TL;DR

This paper introduces a novel zero-order optical resonator created via an optical surface transformation, featuring a small mode volume, an open structure with a continuum of eigenmodes, and versatile applications.

Contribution

It presents a new design of an open, zero-order optical resonator with subwavelength mode volume using optical surface transformation, requiring only a homogeneous medium.

Findings

Resonator has subwavelength mode volume.

Resonator operates as an open system with a continuum of eigenmodes.

Potential applications include optical storage, power combination, and electromagnetic energy squeezing.

Abstract

A novel zero-order resonator has been designed by an optical surface transformation (OST) method. The resonator proposed here has many novel features. Firstly, the mode volume can be very small (e.g. in the subwavelength scale). Secondly, the resonator is open (no reflecting walls are utilized) and resonant effects can be found in a continuous spectrum (i.e. a continuum of eigenmodes). Thirdly, we only need one homogenous medium to realize the proposed resonator. The shape of the resonator can be a ring structure of arbitrary shape. In addition to the natural applications (e.g. optical storage) of an optical resonator, we also suggest some other applications of our novel optical open resonator (e.g. power combination, squeezing electromagnetic energy in the free space).