A cool simulation using FDTD showing the excitaion of Localized Surface Plasmons in metal nanorods. These simulations are done by Prof. Maxim Sukhrev. The external electromagnetic wave excites plasmons (oscillation of electron sea in the particle) in the direction of polarization of incident wave. At a certain resonance frequency of incoming light (which depends on the shape, size and environment), the particle exhibits large scattering and absorption. It also leads to large enhancements in electric field at the surface.
To know more about localized surface plasmons, read my upcoming articles in my plasmonics information center.