A computational study of the interaction of light with silver nanowires of different eccentricity

The interaction of light with isolated and pairs of silver nanowires with ellipsoidal cross-sections is studied with the finite-difference time-domain (FDTD) method. A Drude model frequency-dependent dielectric constant, with parameters fit to empirical data, is employed. We determine the optical spectra, surface plasmon resonances and near-field profiles for various eccentricities and alignments relative to linearly polarized light. For one nanowire, the surface plasmon resonance position red (to a larger extent) and blue shifts as the ellipse is further elongated when the major (long) axis of the ellipse is oriented along or perpendicular to the direction of incident polarization. We also consider the case of two silver nanowires with circular and ellipsoidal cross-sections.