Solving guided wave modes in plasmonic crystals

In this study, we present an interfacial operator approach for solving guided wave modes of plasmonic crystals. They are formulated as an eigenvalue problem of the wavenumber along the axis of the crystal. In this formulation, the permittivity and permeability of the metallic component can be arbitrary functions of frequency. Moreover, a coupling interface method is introduced to facilitate accurate treatment of the interface conditions with an arbitrary shape between the metal and host materials. Numerical results are illustrated for different shapes of plasmonic crystals, and physical significance is discussed.