Suppression of Parasitic Scattering of Surface Plasmon Polariton Propagating over a Rectangular Step

We study the “parasitic” scattering of a surface plasmon-polariton (SPP) when it propagates over a rectangular step located on the metal surface. We propose a method, which makes it possible to completely eliminate the parasitic scattering losses and utilizes the oblique SPP incidence geometry at angles of incidence exceeding a definite “threshold” angle. The results of rigorous numerical simulations confirm high efficiency of the proposed method. The obtained results may find application in novel integrated plasmonic circuits