# BEAMS - Beams scattering through Electromagnetic Axisymmetric Multilayers and Structures - Software Package

Do NOT download the "PWS example data" folder unless needed.

For more details on how to use the package, refer to the README.txt file.

BEAMS is a collection of MATLAB scripts and a Wolfram interactive notebook which together allow the user to calculate the fields of any electromagnetic beam incident on any material structure with at least one axis of continous rotational symmetry. The generated beam is a 3D time-harmonic non-paraxial field valid for all degrees of focusing. This is done in a post-processing manner by ingesting plane wave simulation data (e.g. acquired with a traditional finite-element solver) and applying 3D rotations and the angular spectrum approach to efficiently calculate 3D complex electromagnetic fields. Examples of applications include high-order Gaussian modes incident on a core-shell particle, a polarisation vortex beam incident on a cylinder and non-trivial beams incident on multilayered structures at any angle of incidence. The focus of the beam can be adjusted or even swept in a computationally-efficient manner to obtain data such as force and torque maps.

For an explanation of the physics, see "Efficient post-processing of electromagnetic plane wave simulations to model arbitrary structured beams incident on axisymmetric structures", J. J. Kingsley-Smith & F. J. Rodriguez-Fortuno.

Written by Dr Jack Kingsley-Smith (2023) in the Department of Physics at King's College London.