A generalization of image theory to predict the interaction of multipole fields with plane surfaces

A derivation and computational scheme, based on exact image theory, for the field produced by the interaction of an outgoing vector wave harmonic with an infinite-extent plane surface is presented. The method represents the angular-dependent Fresnel reflection coefficients of the surface as Laplace transforms of a spatially dependent function, which results in the reflected field appearing as a superposition of image sources located at complex points along the normal axis within the surface medium. Exact, analytical formulas are given for the transformed reflection coefficients for arbitrary surface refractive index, and an efficient computation scheme for evaluation of the scattered field coupling between a particle and the surface is presented.