SCATTERING OF ELECTROMAGNETIC-PLANE WAVES BY RADIALLY INHOMOGENEOUS SPHERES - A FINELY STRATIFIED SPHERE MODEL

A new recursive algorithm to calculate the internal and scattered fiel ds of finely stratified inhomogeneous spheres has been developed. No r estriction on the number of layers-the thicknesses of which can be arb itrarily small-is imposed by this method. The number of layers is rest ricted only by the computer's capability: calculations with spheres wi th more than 10,000 layers were successfully performed with a HP work station. The new algorithm circumvents the limitations introduced by t he numerical round-off errors encountered when using the previously de veloped recursive relations to calculate the ratios of Riccati-Bessel functions. Tests and calculations show that the method is stable and a ccurate for a large range of size parameters and optical properties. B y employing the proposed algorithm, the problems encountered in analyz ing the scattering by spheres with continuous-profile refractive indic es can be solved with good accuracy.