Elastic scattering of surface plasmon polaritons: Modeling and experiment

Elastic (in-plane) scattering of surface plasmon polaritons (SPP’s) is modeled by considering isotropic pointlike scatterers whose responses to the incident SPP field are phenomenologically related to their effective polarizabilities. Numerical simulations of single, double, and multiple scattering are presented for randomly situated scatterers showing the interplay between different orders of scattering and localization phenomena. Correlation between the scattering regimes and spatial Fourier spectra of the corresponding SPP intensity distributions is considered. Various optical microcomponents (e.g., straight and curved micromirrors) formed by sets of point scatterers are also simulated, and the stability and dispersion of their characteristics are investigated. The appropriate experimental results for SPP scattering by both random and specially configured sets of microscatterers are reported for two excitation wavelengths (594 and 633 nm) and different metal (silver and gold) films. The near-field optical images obtained are related to the calculated SPP intensity distributions demonstrating that the model developed can be successfully used in studies of SPP elastic scattering, e.g., to design the microcomponents for SPP’s.