Homogenization of plasmonic metasurfaces modeled as transmission-line loads

In this work, we discuss the analytical modeling of single and cascaded plasmonic metasurfaces excited by normally incident plane waves using a transmission-line shunt admittance model. We derive an analytical model that relates the effective surface optical admittance of a single metasurface to its inclusion polarizability and its plane wave reflection and transmission coefficients, and we apply these concepts to predict the wave interaction of more complicated setups in which two stacked surfaces are separated by a varying distance, and possibly rotated with respect to one another, for normal incidence excitation. We show that the analytical model holds very well under suitable conditions, and we verify our analytical results with full-wave numerical simulations, including material dispersion and loss of optical materials.

► Analytical model of ultrathin plasmonic array as transmission-line element.
► Cross-polarization coupling is included, especially relevant when rotation is considered.
► The model is robust in terms of incidence angle, rotation and coupling with other arrays.
► Validation is obtained by comparison with full-wave simulations.