Generalized tensor FDTD method for sloped dispersive interfaces and thin sheets

We present a modified formulation of the Finite-Difference Time-Domain (FDTD) technique that facilitates the accurate modeling of curved plasmonic interfaces. These interfaces appear in structures of interest for the design of optical metamaterials, such as arrays of plasmonic nanorods. Our approach uses the standard rectangular FDTD mesh and tensor effective permittivities for the interface cells, implicitly enforcing field boundary conditions, and is readily applicable to thin curved dispersive layers. We demonstrate the accuracy and effectiveness of our approach with the periodic analysis of a silver nanorod array and the computation of scattering parameters from a thin dispersive ring in a waveguide.