Theoretical analysis of metallic nanohole filled with dispersive material

A theoretical analysis of nanoscale metallic hole filled with a dielectric material is presented. The dispersion characteristics of the guided modes of a dielectric-filled metallic nanohole show interesting characteristics such as negative dispersion which is not normally observed in air-filled structures. Moreover, the material dispersion, taken fully into consideration, is shown to have a significant effect on the modal dispersion of guided modes, specially, at visible range of frequencies. The analysis is carried out using a full vectorial finite element method which can accurately detect the propagation properties of the structure under investigation.