An iterative solution for TM scattering from perturbed circular dielectric cylinders

The electromagnetic scattering from an infinite length dielectric cylinder with a nearly homogeneous and circular cross section is considered, with the electric field of the incident plane wave aligned parallel to the infinite axis (TM/sub z/). An iterative approach is adopted, similar to Born's method, but making use of the Green's function for a perfect circular cylinder. As long as the deviations from a homogeneous circular cylinder are minor, the approach is computationally efficient and accurate, a claim demonstrated by comparisons with a moment-method solution. The issue of convergence is explored with respect to shapes and permittivities of perturbations. A method for a priori determination of the success of the iterative method for arbitrary geometries is also given.