Creating electromagnetic cavities using transformation optics

TL;DR

This paper explores how transformation optics can be used to design electromagnetic cavities with customizable mode confinement by applying radial and azimuthal coordinate transformations, enabling subwavelength mode confinement with right-handed materials.

Contribution

It introduces a method to design electromagnetic cavities using transformation optics, including radial and azimuthal transformations, for improved mode control and confinement.

Findings

Radial transformations determine bound mode dispersion relations.

Azimuthal transformations can manipulate mode numbers.

Combining transformations achieves perfect subwavelength confinement.

Abstract

We investigate the potential of transformation optics for the design of novel electromagnetic cavities. First, we determine the dispersion relation of bound modes in a device performing an arbitrary radial coordinate transformation and we discuss a number of such cavity structures. Subsequently, we generalize our study to media that implement azimuthal transformations and we show that such transformations can manipulate the azimuthal mode number. Finally, we discuss how the combination of radial and azimuthal coordinate transformations allows for perfect confinement of subwavelength modes inside a cavity consisting of right-handed materials only.