Backaction in metasurface etalons

Abstract

We consider the response of etalons created by a combination of a conventional mirror and a metasurface, composed of a periodic lattice of metal scatterers with a resonant response. This geometry has been used previously for perfect absorption, in so-called Salisbury screens, and for hybridization of localized plasmons with Fabry-Perot resonances. The particular aspect we address is if one can assume an environment-independent reflectivity for the metasurface when calculating the reflectivity of the composite system, as in a standard Fabry-Perot analysis, or whether the fact that the metasurface interacts with its own mirror image renormalizes its response. Using lattice sum theory, we take into account all possible retarded dipole-dipole interactions of scatterers in the metasurface amongst each other, and through the mirror. We show that while a layer-by-layer Fabry-Perot formalism captures the main qualitative features of metasurface etalons, in fact the mirror modifies both the polarizability and reflectivity of the metasurface in a fashion that is akin to Drexhage's modification of the radiative properties of a single dipole.Comment: 10 pages, 5 figure

A simple transfer-matrix model for metasurface multilayer systems

“…In principle any full-wave method could be used. For our work we use a semi-analytical approach that constructs the response of a metasurface on the basis of scatterer polarizability, and using Ewald lattice summation to account for all the interactions in the lattice [28,54,55].…”

“…In principle, the metasurface transfer matrix M meta (r a , t a ) allows to insert the reflection and transmission of a metasurface as calculated by any modeling approach. In this work we focus for demonstration purposes on behavior of metasurface etalons in which the metasurface is simply a non-diffractive sheet of resonant nanoscale polarizabilities placed in a lattice, as for instance obtained by making sufficiently dense arrays of plasmon antenna particles [28,54,55]. To model reflection and transmission of such a layer one must first specify the polarizability of a single scatterer, then include its radiative damping to obtain a selfconsistent t-matrix, and finally account for all the nearfield and far-field multiple scattering interactions with its neighbors in the lattice.…”

“…To model reflection and transmission of such a layer one must first specify the polarizability of a single scatterer, then include its radiative damping to obtain a selfconsistent t-matrix, and finally account for all the nearfield and far-field multiple scattering interactions with its neighbors in the lattice. A didactic introduction is provided by de Abajo [54], while implementation details for arbitary lattice symmetries and polarizability tensors are listed in [28,55]. In this work we assume that the polarizability is scalar, purely electric (p 4πεα E ) and we use a unit system in which polarizability α E has units of volume.…”

“…Such structures control reflected waves in amplitude, phase and polarization through constructive and destructive interference of scattering contributions from a ground plane and a scatterer array [3,27]. These structures essentially constitute a metasurface etalon, where both the round trip phase, controlled by separation, and the reflection phase of the metasurface reflector, control response [21,23,26,28]. Beyond applications as antireflection devices, absorption enhancers in photodetection scenarios, and as metasurface pixels from which to build metasurface devices, these metasurface etalons also have been proposed for plasmonic color printing and polarization multiplexing therein [29][30][31][32][33].…”

Electrodynamics of Magnetoelectric Media and Magnetoelectric Fields

“…[72,73] It is assumed that bianisotropy (chirality) in these metamaterials arises from a local ME effect. [74][75][76][77] Such a "first-principle," "microscopic-scale" ME effect of a structure composed by "glued" pairs of electric and magnetic dipoles raises many questions. First, it is unclear what the near field of this structure is.…”