Restoring of optical resonances in subwavelength hyperbolic etalons

TL;DR

This paper demonstrates that hyperbolic metamaterials enable optical resonances in ultra-thin structures, allowing for high-contrast angular filtering and potential miniaturization of optical devices.

Contribution

It introduces a method to restore optical resonances in deep subwavelength structures using hyperbolic metamaterials, a novel approach for device miniaturization.

Findings

Hyperbolic slabs exhibit etalon resonances at nanometric thicknesses.

Hyperbolic dispersion enables coupling with high longitudinal wavevectors.

High-contrast optical angular filtering achieved in subwavelength structures.

Abstract

We give a solution to the fundamental problem of restoring optical resonances in deep subwavelength structures by resorting to indefinite metamaterials. We prove that a nanometric thick hyperbolic slab with very small permittivities exhibits etalon resonances and provides high-contrast optical angular filtering. This is possible since the hyperbolic dispersion allows the vacuum radiation to couple with medium plane waves with longitudinal wavenumbers large enough to yield optical standing waves within the nanometric slab thickness. Our findings can form the basis of a novel way for shrinking optical devices down to the deep subwavelength scale.