Light scattering by multi-layered axisymmetric particles

          V G Farafonov^1, M S Prokopjeva^2 and V B Il'in^2

    ^1 St.Petersburg University of Aerocosmic Instrumentation,
       Bol.Morskaya ul. 67, St.Petersburg 190000, Russia

    ^2 Sobolev Astronomical Institute, St.Petersburg University,
       Bibliotechnaya pl. 2, St.Petersburg 198504, Russia


                         Abstract

We present an exact solution to the problem of light scattering by
multi-layered axisymmetric particles and a numerical code
implementing this solution.
The main features of the solution are: separation of the incident,
scattered, and internal fields into two parts with a proper
choice of scalar potentials for each of them, expansion of
the potentials in terms of the spherical wave functions,
usage of surface integral equations
and truncated systems of linear algebraic
equations relative to the coefficients of the potential expansions.
The solution is also formulated in a recursive way.

The numerical code developed has shown that the solution really
allows a treatment of axisymmetric particles
of quite different internal structures
(e.g., combinations of a spherical core, a prolate spheroidal layer and
an oblate spheroidal mantle).
Some illustrative results
of calculations of the optical properties of layered particles
are given and briefly discussed.