Electromagnetic tunneling properties of sandwich structure containing single negative material

Abstract

The electromagnetic tunneling properties of the sandwich structure with single negative material/positive index material (single negative material)/ single negative material are experimentally investigated based on the theoretical analysis. The tunneling properties come from the resonance coupling between the incident plane wave and the surface and bulk polaritons. First, the surface or bulk polariton dispersion relations under zero incident condition are discussed and calculated. It is found that the positive index material sandwiched by single negative material possesses bulk polaritons, the resonance frequency of polariton decreases with the thickness of the central layer increasing. The sandwhic structures composed of different single negative materials possess double surface polaritons, and the two surface polaritons degenerate with the thickness of the central single negative material layer. Subsequently, the tunneling properties of the sandwich structures are measured, which are consistent well with the simulation and theoretical analyses. The two structures both possess tunable tunneling modes, their properties have potential applications in designing tunable single or multiple-channeled filters.