An omnidirectional retroreflector based on the transmutation of dielectric singularities

TL;DR

This paper presents a novel metamaterial-based omnidirectional retroreflector that transmutates dielectric singularities into topological defects, enabling broadband, robust microwave retroreflection with potential applications in visible light.

Contribution

It introduces a new method to realize devices requiring dielectric singularities by transforming them into topological defects in metamaterials, advancing transformation optics applications.

Findings

Demonstrated omnidirectional microwave retroreflection

Achieved broadband and robust performance

Potential applicability to visible light frequencies

Abstract

In the field of transformation optics, metamaterials mimic the effect of coordinate transformations on electromagnetic waves, creating the illusion that the waves are propagating through a virtual space. Transforming space by appropriately designed materials makes devices possible that have been deemed impossible. In particular, transformation optics has led to the demonstration of invisibility cloaking for microwaves, surface plasmons and infrared light. Here we report the achievement of another "impossible task". We implement, for microwaves, a device that would normally require a dielectric singularity, an infinity in the refractive index. We transmute a singularity in virtual space into a mere topological defect in a real metamaterial. In particular, we demonstrate an omnidirectional retroreflector, a device for faithfully reflecting images and for creating high visibility, from all directions. Our method is robust, potentially broadband and similar techniques could be applied for visible light.