Optical properties of model anisotropic particles on or near a perfectly reflecting surface

In the framework of image theory the full scattering pattern from model anisotropic particles on a perfectly reflecting surface is calculated for an arbitrary direction of the incident field. The particles on the surface are modeled either as clusters of spherical scatterers or as clusters of hemispheres whose flat faces lie on the reflecting surface. Our approach is based on the expansion of all the fields in terms of spherical multipoles whose transformation properties are used to yield a compact expression for the scattered intensity both from a single particle as a function of its orientation and from a dispersion of randomly oriented particles. The patterns that were calculated for several model scatterers show some features that may provide useful information about the possible anisotropy of actual particles on a reflecting surface. 25 refs., 4 figs