Radiative absorption, fluorescence, and scattering of a classical dipole near a lossless interface: a unified description

Abstract

A simple input–output formalism based on the Lorentz reciprocity theorem is presented for the study of a classical radiating dipole near a lossless interface. The problems of dipole absorption, fluorescence, and scattering are considered in a unified description, and the effects of the interface (a simple dielectric here) are shown to be broadly twofold. First, the channeling of radiation into and out of the dipole is modified. Second, the intrinsic dipole polarizability is found to be modified, leading to an effective absorption (or scattering) cross section that depends on the states of both the dipole and the driving field. These results are particularly applicable to studies involving evanescent-wave microscopy.