Transformation-optics macroscopic visible-light cloaking beyond two dimensions

TL;DR

This paper reports the first experimental demonstration of a macroscopic, three-dimensional visible-light cloaking device based on transformation optics, achieving near-3D invisibility with verified light trajectories and optical path lengths.

Contribution

It introduces the first 3D visible-light cloaking device that works beyond two dimensions, demonstrating near-3D invisibility at a macroscopic scale.

Findings

Achieved near-3D invisibility in a macroscopic cloak.

Verified light ray trajectories and optical path lengths experimentally.

Maintained wide-angle invisibility in multiple intersecting 2D planes.

Abstract

Transformation optics, a recent geometrical design strategy of controlling light by combining Maxwell's principles of electromagnetism with Einstein's general relativity, promises without precedent an invisibility cloaking device that can render a macroscopic object invisible in three dimensions. However, most previous proof-of-concept transformation-optics cloaking devices focused predominantly on two dimensions, whereas detection of a macroscopic object along its third dimension was always unfailing. Here, we report the first experimental demonstration of transformation-optics macroscopic visible-light cloaking beyond two dimensions. This almost-three-dimensional cloak exhibits three-dimensional (3D) invisibility for illumination near its center (i.e. with a limited field of view), and its ideal wide-angle invisibility performance is preserved in multiple two-dimensional (2D) planes intersecting in the 3D space. Both light ray trajectories and optical path lengths have been verified experimentally at the macroscopic scale, which provides unique evidence on the geometrical nature of transformation optics.