Design and analytically full-wave validation of the invisibility cloaks, concentrators, and field rotators created with a general class of transformations

TL;DR

This paper presents a comprehensive analytical framework for designing and validating electromagnetic transformation devices like cloaks, concentrators, and rotators, demonstrating their functionalities and robustness through full-wave analysis.

Contribution

It introduces a general analytical method for full-wave validation of transformation electromagnetic devices created with continuous functions, including novel designs like power flux amplifying concentrators and spherical rotators.

Findings

Cloaks can be made insensitive to boundary perturbations.

Left-handed material coatings enable power flux amplification in concentrators.

Spherical rotators can manipulate wave vectors and polarization.

Abstract

We investigate a general class of electromagnetic devices created with any continuous transformation functions by rigorously calculating the analytical expressions of the electromagnetic field in the whole space. Some interesting phenomena associated with these transformation devices, including the invisibility cloaks, concentrators, and field rotators, are discussed. By carefully choosing the transformation function, we can realize cloaks which are insensitive to perturbations at both the inner and outer boundaries. Furthermore, we find that when the coating layer of the concentrator is realized with left-handed materials, energy will circulate between the coating and the core, and the energy transmits through the core of the concentrator can be much bigger than that transmits through the concentrator. Therefore, such concentrator is also a power flux amplifier. Finally, we propose a spherical field rotator, which functions as not only a wave vector rotator, but also a polarization rotator, depending on the orientations of the spherical rotator with respect to the incident wave direction. The functionality of these novel transformation devices are all successfully confirmed by our analytical full wave method, which also provides an alternate computational efficient validation method in contrast to numerical validation methods.