Coupled edge plasmon modes of metal/dielectric multi-wedges

We present a metallic/dielectric multi-wedge model to investigate the coupled edge plasmon modes (CEPMs), where all wedges have a common edge and the wave propagates along the edge direction. A general theoretical method valid to many practical structures is presented. The analytical dispersion relations of CEPMs in these structures are obtained and the CEPM properties are discussed with numerical results and the dispersion relations. For all structures mentioned in this paper, we find that the structures containing an even number of metallic wedges own four CEPMs and those with an odd-number of metallic wedges have two CEPMs. Further the periodic structures containing any odd number of periods and any even number of periods possess their common CEPMs, respectively.