Study of scattering patterns and subwavelength scale imaging based on finite-sized metamaterials

Abstract

A metamaterial slab, used as a superlens in a subwavelength imaging system, is frequently assumed homogeneous. It is the bulk properties of the metamaterial which are responsible for the resolution of the transferred information in the image domain, as a result of high transverse wavevector coupling. However, how in a discretized metamaterial, individual meta-atoms (i.e., the meta-elements composing a negative index metamaterial slab) contribute to the imaging process is still actively studied. The main aim of this paper is to investigate the consequences of using only a few meta-atoms as a negative index slab-equivalent for subwavelength scale imaging. We make a specific choice for a meta-atom and investigate its resonant scattering patterns. We report on how knowledge of these 3D scattering patterns provides a means to understand the transfer of high spatial frequencies and assist with the design an improved negative index slab.

Superresolved image reconstruction from incomplete data

“…For an object classified as a weak scatterer, i.e. that the first Born approximation is valid then a necessary condition is that the product of target's permittivity, its characteristic dimension, a, and wave number, k, should be much less than unity [6]. This is expressed mathematically as kVa <<1 where V is some measure of the maximum value that V(r) = ε(r) -1 takes.…”

“…Our goal to figure out how the field in the image domain of a negative index lens relates to the permittivity profile of the scattering object, and how the usual requirements of multiple incident field directions or wavelengths needed for inverse scattering H algorithms, can be still be exploited. We say this since for the foreseeable future, negative index lenses made from metamaterials, are likely to be quite limited in both depth of focus and bandwidth, [5][6][7][8].…”

Super/Zero Scattering Characteristics of Circular SRR Arrays

“…The strong interest is motivated by the possibility to tailor the electromagnetic response that a periodic structure of metamaterials allows, which promises to have a significant impact in physics, optics and material science. Effective permittivities and permeabilities of metamaterials designed to range from negative to positive values have many important applications such as invisible cloaks [7][8][9][10], superlenses [11][12][13], microwave horn antennas [14] as well as other electromagnetic devices [15,16].…”