Scattering of evanescent wave by two cylinders near a flat boundary

TL;DR

This paper presents a numerical boundary integral equations method to analyze how evanescent waves scatter off two cylinders near a boundary, with applications in near-field optical microscopy.

Contribution

It introduces a special Green function to efficiently solve the scattering problem involving complex geometries near an interface.

Findings

Energy flux varies with probe position

Pattern simulation of probe and sample in microscopy

Numerical method effectively models evanescent wave scattering

Abstract

Two-dimensional problem of evanescent wave scattering by dielectric or metallic cylinders near the interface between two dielectric media is solved numerically by boundary integral equations method. A special Green function was proposed to avoid the infinite integration. A pattern with a circular and a prolate elliptic cylinders, respectively, is suggested to simulate the sample and the probe in near-field optical microscopy. The energy flux in the midplane of the probe-cylinder is calculated as a function of its position.