Gaussian beam scattering from a dielectric cylinder, including the evanescent region
Related Experiment Video
Updated: Jun 18, 2026

Controlled Synthesis and Fluorescence Tracking of Highly Uniform Poly(N-isopropylacrylamide) Microgels
Published on: September 8, 2016
Peter Pawliuk1, Matthew Yedlin
1Department of Electrical and Computer Engineering, The University of British Columbia, 2329 West Mall, Vancouver, British Columbia, Canada V6T 1Z4. ppawliuk@interchange.ubc.ca
Abstract:
The scattering of a two-dimensional Gaussian beam from a homogeneous dielectric cylinder is analyzed using a plane-wave spectrum. Special attention is given to the computation of the evanescent field of the beam and its effect in the scattering. A comparison is made between the evanescent field in Cartesian coordinates and in cylindrical coordinates as a sum of cylindrical waves. The field given by the cylindrical wave equation is found to converge spatially as we include more Bessel modes. The evanescent field incident on the dielectric cylinder is found to cause radiating waves to form and propagate outward.
Related Concept Videos
Gauss's Law in Dielectrics
Gauss's Law: Cylindrical Symmetry
Gauss's Law: Spherical Symmetry
Gauss's Law: Problem-Solving
Electrostatic Boundary Conditions in Dielectrics
Consider a case where both the mediums across a boundary are two different dielectric materials. Recall that the electric field and electric displacement are proportional and related through the material's permittivity.
Gauss's Law

