Three-dimensional Electromagnetic Void Space

TL;DR

This paper introduces a 3D electromagnetic void space realized through all-dielectric photonic crystals, exhibiting unique wave manipulation properties such as boundary control, wave steering, and impurity immunity, both theoretically and experimentally.

Contribution

It demonstrates the creation of a 3D electromagnetic void space with vanishing permittivity and permeability, enabling unprecedented control over electromagnetic waves.

Findings

Realization of 3D electromagnetic void space with Dirac-like dispersion.

Experimental demonstration of boundary-control transmission switching.

Observation of impurity-immunity in 3D void space.

Abstract

We report a realization of three-dimensional (3D) electromagnetic void space. Despite occupying a finite volume of space, such a medium is optically equivalent to an infinitesimal point where electromagnetic waves experience no phase accumulation. The 3D void space is realized by constructing all-dielectric 3D photonic crystals such that the effective permittivity and permeability vanish simultaneously, forming a six-fold Dirac-like point with Dirac-like linear dispersions at the center of the Brillouin Zone. We demonstrate, both theoretically and experimentally, that such a 3D void space exhibits unique properties and rich functionalities absent in any other electromagnetic media, such as boundary-control transmission switching and 3D perfect wave-steering mechanisms. Especially, contrary to the photonic "doping" effect in its two-dimensional counterpart, the 3D void space exhibits an amazing property of "impurity-immunity". Our work paves a road towards the realization of 3D void space where electromagnetic waves can be manipulated in unprecedented ways.