Ultrathin All-Angle Hyperbolic Metasurface Retroreflectors Based on Directed Routing of Canalized Plasmonics

TL;DR

This paper introduces an ultrathin, all-angle retroreflector using hyperbolic plasmonic metasurfaces that efficiently redirects incident waves back along their original path, with high efficiency and wide angular coverage.

Contribution

The authors propose and experimentally demonstrate a novel hyperbolic plasmonic metasurface design enabling ultrathin, all-angle retroreflection through canalized spoof surface plasmons, overcoming size and bandwidth limitations.

Findings

Maximum efficiency of 83.2% achieved

Field of view extends up to 53 degrees

Prototype thickness approximately equal to the wavelength

Abstract

Retroreflectors that can accurately redirect the incident wave in free space back along its original channel provide unprecedented opportunities for light manipulation in wireless communication. However, to the best of our knowledge, the existing methods of designing retroreflectors suffer from either the bulky size, narrow angular bandwidth, or time-consuming post-processing. Here, a scheme of designing ultrathin and all-angle retroreflectors based on hyperbolic plasmonic metasurfaces is proposed and experimentally demonstrated. The physical mechanism underlying this scheme is the high-efficiency all-angle transition between the traveling waves in free space and the canalized spoof surface plasmon (SSP) on the hyperbolic plasmonic metasurfaces (HPMs). In this case, the strong confinement characteristic benefited from the enhanced light-matter interaction enables us to route and retroreflect the canalized SSP with extremely ultrathin structures. As proof of the scheme, a retroreflector prototype with a thickness approximately equal to the central wavelength is designed and fabricated. Further experimental investigation obtains a maximum efficiency of 83.2% and a half-power field of view up to 53{\deg}. This scheme can find promising applications in target detection, remote sensing, and diverse on-chip light control devices.