Hidden progress: broadband plasmonic invisibility

TL;DR

This paper demonstrates broadband plasmonic cloaking using structured metal surfaces with dielectric materials, achieving extended invisibility over 650-900 nm through a non-resonant metamaterial approach validated by experiments.

Contribution

It introduces a novel non-resonant plasmonic metamaterial that enables broadband cloaking, surpassing previous bandwidth limitations in electromagnetic invisibility.

Findings

Achieved cloaking over 650-900 nm wavelength range.

Validated theoretical predictions with experimental surface light intensity mapping.

Demonstrated control of surface plasmon polaritons for cloaking applications.

Abstract

The key challenge in current research into electromagnetic cloaking is to achieve invisibility over an extended bandwidth. There has been significant progress towards this using the idea of cloaking by sweeping under the carpet of Li and Pendry, with dielectric structures superposed on a mirror. Here, we show that we can harness surface plasmon polaritons at a metal surface structured with a dielectric material to obtain a unique control of their propagation. We exploit this to control plasmonic coupling and demonstrate both theoretically and experimentally cloaking over an unprecedented bandwidth (650-900 nm). Our non-resonant plasmonic metamaterial allows a curved reflector to mimic a flat mirror. Our theoretical predictions are validated by experiments mapping the surface light intensity at the wavelength 800 nm.