Dispersion control in coated wire media slabs

Wire media (WM) metamaterials have many applications, specifically imaging, due to their hyperbolic dispersion properties. Here we consider WM comprised of wires with dielectric coatings and explore how the coating affects the dispersion and its possible applications. Using an effective medium approximation we find the slab modes of dielectric-coated WM and compare the results to numerical simulations. This shows that for potential applications we must consider parameters where these approximations cannot be used. We use numerical results to further explore the effect of strong coatings and lattice distortion and develop a semianalytic approach to tailor the dispersion relation of WM slabs. We use this to find a coating that optimizes control over the dispersion in one dimension, and discuss advantages for imaging applications such as the metamaterial hyperlens and the resonant metalens.