Simulation of Surface Plasmon Excitation in a Plasmonic Nano-Wire Using Surface Integral Equations

In this paper, scattering of a plane and monochromatic electromagnetic wave from a nano-wire is simulated using surface integral equations. First, integral equations governing unknown fields on the surface is obtained based on Strattun-Cho surface integral equations. Then, the interaction of the wave with a non-plasmonic as well as a palsmonic nano-wire is considered. It is shown that in scattering of the wave from the non-plasmonic nano-wire the simple phenomena of refraction and transmission occur. On the other hand, the interaction of TM polarized light with plasmonic nano-wire excites surface plasmon waves. Simulations show that no surface plasmon is excited in interaction of TE polarized light with plasmonioc nano-wire. It is observed that, while increasing the frequency of incident light, the regime of scattering goes from electrostatic limit to simple geometric limit through diffraction region. In continuation, charge distribution induced by surface plasmon is simulated for different times. The simulation shows that a wave-like surface charge is excited and propagates on the surface. There is a very weak charge distribution within the nano-wire indicating that no light penetrates the wire.