Electromagnetic forces and torques in nanoparticles irradiated by a plane wave

TL;DR

This paper introduces a numerical method to calculate electromagnetic forces and torques on arbitrarily-shaped nanoparticles in plane wave illumination, enhancing understanding of optical manipulation techniques.

Contribution

It presents a new boundary element method-based approach for computing electromagnetic forces and torques on complex-shaped particles in optical fields.

Findings

Validated method on spherical particles

Extended calculations to non-spherical objects

Provided analytical expressions for forces and torques

Abstract

Optical tweezers and optical lattices are making it possible to control small particles by means of electromagnetic forces and torques. In this context, a method is presented in this work to calculate electromagnetic forces and torques for arbitrarily-shaped objects in the presence of other objects illuminated by a plane wave. The method is based upon an expansion of the electromagnetic field in terms of multipoles around each object, which are in turn used to derive forces and torques analytically. The calculation of multipole coefficients are obtained numerically by means of the boundary element method. Results are presented for both spherical and non-spherical objects.