Light scattering by metallic surfaces with subwavelength patterns

Abstract

We present a simple and intuitive model for analyzing the optical response of metallic surfaces patterned by arbitrary one-dimensional arrays of subwavelength (sub-$\ensuremath{\lambda}$) structures. In the present microscopic approach, the near-field response close to the surface is composed of a linear combination of elementary hybrid waves, which are shown to solely depend on the frequency and to be merely independent of the incident illumination and of the scatterer geometry. The model is tested against fully vectorial computational results obtained for simple systems that can be handled numerically with fully vectorial methods and, in contrast to classical models that solely rely on surface plasmon polaritons, the present model is shown to be highly accurate over a broad spectral range below the plasma frequency of the metal.