Effective medium theory of subwavelength arrays of metallic nanowires: a numerical approach based on modal propagation method

One of the major issues in the modeling of subwavelength optical materials resides in how to compute the effective properties of such media. An efficient technique must be able to describe appropriately the electromagnetic response of the overall structure. Within this context, this work is focused on the calculation of effective parameters of metallic silver nanowires embedded in alumina background. An algorithm based on modal propagation is considered in order to estimate the refractive index at the visible spectrum. The resonances obtained in the computing model are compared to the predictions of analytical Bruggeman and Maxell-Garnett theories and analyzed by regarding excitation of surface modes at the metal-dielectric interface.