Metasurfaces for general transformations of electromagnetic fields

Abstract

In this review paper I discuss electrically thin composite layers, designed to perform desired operations on applied electromagnetic fields. Starting from a historical overview and based on a general classification of metasurfaces, I give an overview of possible functionalities of the most general linear metasurfaces. The review is concluded with a short research outlook discussion.

Spatial transformations: from fundamentals to applications

“…On the other, twodimensional waves (such as waves propagating on a surface) can be controlled by metasurfaces to perform a variety of functions, including beam splitting, wavefront transformations and conversion between surface (two-dimensional) and space (three-dimensional) waves, described by Martini et al [19]. The design of metasurfaces to achieve such functionality is a similar challenge to designing three-dimensional metamaterials, in many respects, but the methodologies described in this issue demonstrate convincingly how this may be achieved at both radio and optical frequencies [19][20][21].…”

“…On the one hand, a two-dimensional device can be designed to perform a variety of transformations on a wave propagating in three-dimensional space, as thoroughly described by Tretyakov and Estakhri et al [20,21]. On the other, twodimensional waves (such as waves propagating on a surface) can be controlled by metasurfaces to perform a variety of functions, including beam splitting, wavefront transformations and conversion between surface (two-dimensional) and space (three-dimensional) waves, described by Martini et al [19].…”

“…The second paper in this group, by Tretyakov, complements the first by reviewing metasurfaces that transform waves propagating through, rather than along (tangential to), the metasurface [20]. Beginning with a discussion of what a metasurface is, he highlights the usefulness of such a twodimensional electromagnetic object in the context of Huygens' equivalence principle.…”

“…. the electromagnetic fields created by arbitrary sources in an arbitrary volume V can be found as the fields created by equivalent currents on the volume surface S' [20]. Equivalently, the fields outside a volume can be controlled by either the fields within that volume or by the surface currents surrounding it.…”

Metamaterials for Microwave Radomes and the Concept of a Metaradome: Review of the Literature

“…Despite their small thickness, metasheets can fully control reflection, absorption, and transmission of electromagnetic waves (e.g., plane, surface or guided), including polarization, phase, and amplitude of the transmitted wave [35,[43][44][45]. As shown in literature, it is theoretically possible to design devices for almost arbitrary manipulations of plane waves, which results in such devices as self-oscillating teleportation metasheets, transmitarrays, double current sheets, and metasheets formed by only lossless components [46].…”