Light Scattering on Two Parallel Subwavelength Cylinders

TL;DR

This paper derives an analytical solution for light scattering on two parallel subwavelength cylinders, accounting for different sizes and dielectric properties, validated by numerical simulations, advancing understanding of plasmonic interactions.

Contribution

It introduces a conformal transformation approach to analytically solve scattering by two cylinders with different diameters and dielectric constants, extending previous models.

Findings

Analytical near-field intensity distribution matches numerical results.

Green's function enables higher-order decomposition analysis.

Solution applicable to cylinders with varying sizes and dielectric properties.

Abstract

The plasmon resonance has found important application in various systems, e.g., nanoantennas, solar panels, refractive index sensors. Unfortunately, a few analytical solutions for such systems are known. The work aims to find a solution for scattering by a plane electromagnetic wave on two parallel cylinders. When their diameters and the gap between them are less than the radiation wavelength, the quasistatic approximation is valid. We build up a conformal transformation that maps Cartesian into bipolar orthogonal coordinates and represent the scattered field as a decomposition by eigenfunctions of the Laplace operator. The near-field intensity distribution is shown to coincide with numerical calculation performed by COMSOL Multiphysics. Green's function obtained allows one to find also higher decomposition orders. Compared to previous studies, we treat the general case of cylinders with different diameters and dielectric constants.