Tunable Localization of Light Using Nested Invisible Metasurface Cavities

TL;DR

This paper introduces nested invisible metasurface cavities that enable tunable light localization and high quality factors, achieved through nanodisk-based dielectric metasurfaces operating near electric resonances.

Contribution

It presents a novel method of nesting invisible cavities to enhance field localization and tunability, with practical implementation in optical metasurfaces.

Findings

Nested cavities allow control over localized field strength.

The quality factor can be tuned by adjusting cavity positioning.

Implementation demonstrated with nanodisk dielectric metasurfaces.

Abstract

An invisible cavity is an open resonant device that confines a localized field without producing any scattering outside of the device volume. By exploiting the scatter-less property of such device, it is possible to nest two invisible cavities, as the outer cavity would simply not notice the presence of the inner one, regardless of their relative position. As a result, the position of the inner cavity becomes a means to easily control the field localized inside the cavity and its quality factor. In this paper, we discuss the properties of nested invisible cavities as a simple method to achieve stronger localized fields and high tunable quality factor. Furthermore, we show that in optics, these cavities can be implemented using nanodisk-based dielectric metasurfaces that operate near their electric resonances.