Frequency range and explicit expressions for negative permittivity and permeability for an isotropic medium formed by a lattice of perfectly conducting Ω\Omega particles

An analytical model is presented for a rectangular lattice of isotropic scatterers with electric and magnetic resonances. Each isotropic scatterer is formed by putting appropriately 6 $\Omega$-shaped perfectly conducting particles on the faces of a cubic unit cell. A self-consistent dispersion equation is derived and then used to calculate correctly the effective permittivity and permeability in the frequency band where the lattice can be homogenized. The frequency range in which both the effective permittivity and permeability are negative corresponds to the mini-band of backward waves within the resonant band of the individual isotropic scatterer.Comment: 25 pages, 6 figure

On effective electromagnetic parameters of artificial nanostructured magnetic materials

In this paper we discuss effective material parameter description of new nanostructures designed to perform as artificial magnetic materials for vis- ible light. Among these structures there are various split-ring resonators, dual-bar structures, fishnet layers and other geometries. Artificial magnetic response in these structures appears due to weak spatial dispersion effects, and it is important to study the conditions under which the magnetic re- sponse can be adequately measured with effective permeability tensor. On the examples of dual bars and split rings we show that this is possible only under some quite restrictive conditions. In the general case, more compli- cated constitutive relations with more effective material parameters need to be developed.Comment: 20 pages, 2 figure

Subwavelength resolution for horizontal and vertical polarization by coupled arrays of oblate nanoellipsoids

A structure comprising a coupled pair of two-dimensional arrays of oblate plasmonic nanoellipsoids in a dielectric host medium is proposed as a superlens in the optical domain for both horizontal and vertical polarizations. By means of simulations it is demonstrated that a structure formed by silver nanoellipsoids is capable of restoring subwavelength features of the object for both polarizations at distances larger than half-wavelength. The bandwidth of subwavelength resolution is in all cases very large (above 13%).Comment: 3 pages with 6 figure