Cylindrical wave approach to observe the scattering of surface plasmon-polariton waves from a cylinder

Abstract

Surface waves are the solutions of Maxwell's equations in the frequency domain at the at interface of two di erent materials. Poynting vector averaged over time has a signi cant component parallel to the interface decays at su ciently large distances normal to the interface. If one of the partnering materials is a metal and the other a dielectric, the surface waves are called surface plasmon-polariton (SPP) waves. Surface plasmon-polariton (SPP) waves are the most extensively studied waves among various types of surface waves because they are easy to excite and have been used in many optical applications particularly for plasmonic communication, sensing, and harvesting solar energy. In all of these applications, especially on-chip plasmonic communication, scattering can be an important issue to contend with. Therefore, the objective of this paper is to theoretically inspect the scattering pattern of SPP waves from a perfect electric conductor (PEC) cylindrical scatterer. The cylindrical wave approach is used to solve the scattering problem by a cylindrical object placed below a metallic layer. The scattering is investigated thoroughly by changing the size of the scatterer and its distance from the interface along which the SPP wave is excited. As size of the scatterer increases, the scattering increases signi cantly. On the other hand, when the distance of the scatterer from the interface is increased, the scattered eld becomes small. Two-dimensional eld maps are produced for the incidence angle at which SPP is excited. Numerical results are also presented for other incidence angles to make a comparison. Furthermore, the forward and backward far- elds are signi cantly enhanced if the SPP wave is scattered in comparison to when SPP wave is not present.