Finite-difference time-domain simulation of plasmonic nanoparticles

Recently noble metal nanoparticles have attracted strong interest due to their potential as nano-scale waveguides and lumped elements in the optical frequency range. Engheta et. al., (2005) showed that a non-metal nanoparticle can serve as a capacitor whereas a metal nanoparticle can serve as an inductor. This idea is interesting for the design of optical metamaterials, if the proposed nanoparticles are employed to implement the inductive/capacitive blocks in 2-D/3-D negative-refractive-index transmission line (NRI-TL) based metamaterials. Due to the difficulty of adjusting to the inherent numerical intricacies of this problem, simulating plasmonic nanoparticles becomes a challenge for commercial packages. Full-wave analysis through the finite-difference time-domain (FDTD) can provide an alternative to them. In this paper, we present the FDTD analysis of a silver nano sphere and compare its field pattern to that of a dielectric nano sphere. These results are also validated against data obtained from quasi-static theory