Mimicking Surface Plasmons with Structured Surfaces

TL;DR

This paper demonstrates that structured surfaces with perforations can mimic surface plasmons by controlling electromagnetic surface excitations, enabling customizable plasmonic properties for advanced optical applications.

Contribution

It establishes a theoretical connection between natural surface plasmons and engineered structured surfaces, allowing for designer surface plasmon dispersion control.

Findings

Structured surfaces can support surface modes similar to natural plasmons.

Effective permittivity of perforated surfaces follows plasma-like behavior.

Design flexibility enables tailored surface plasmon properties.

Abstract

Metals such as silver support surface plasmons: electromagnetic surface excitations localised near the surface which originate from the free electrons of the metal. Surface modes are also observed on highly conducting surfaces perforated by holes. We establish a close connection between the two, showing that electromagnetic waves in both materials are governed by an effective permittivity of the same plasma form. Because the size and spacing of holes can readily be controlled on all relevant length scales, this gives the opportunity to create designer surface plasmons with almost arbitrary dispersion in frequency and in space, opening new vistas in surface plasmon optics.