Abstract
In this paper we introduce a versatile and numerically efficient computational technique to model the problem of scattering from plasmonic nanorod antennas. The key to achieving the numerical efficiency is to utilize macro basis functions (MBFs) that taking into account the physics of the problem to reduce the size of matrix equation we need to solve. Closed form formulations are presented for computing the fields by the transverse and longitudinal MBFs that enable us to generate the required matrix elements rapidly, while ensuring that the matrix is well-conditioned. We show that the transverse and longitudinal components of polarization current and all of the components of the scattered fields can be computed very accurately by employing only a few MBFs, i.e., by solving a relatively small-size matrix equation. The accuracy of our modeling technique has been successfully demonstrated by comparing the simulation results with those derived by using the finite difference time domain (FDTD) technique, which is considerably more time-consuming than the present approach. Interesting physical phenomena such as surface plasmon modes for polarization currents and resonance behaviors of plasmonic nanorods are illustrated. (C) 2011 American Institute of Physics. [doi:10.1063/1.3597819]