Light Scattering on Nanowire Antennas: A Semi-Analytical Approach

Two semi-analytical approaches to solve the problem of light scattering on nanowire antennas are developed and compared. The derivation is based on the exact solution of the plane wave scattering problem in case of an infinite cylinder. The original three-dimensional problem is reduced in two alternative ways to a simple one-dimensional integral equation, which can be solved numerically by a method of moments approach. Scattering cross sections of gold nanowire antennas with different lengths and aspect ratios are analysed for the optical and near-infrared spectral range. Comparison of the proposed semi-analytical methods with the numerically rigorous discrete dipole approximation method demonstrates good agreement as well as superior numerical performance.