Optical properties of an atom in the vicinity of a metal or dielectric are different from those in free space. The spontaneous decay of an atom with two degenerate levels is studied, where the relaxation operator is obtained as a function of the atom-surface separation and the complex bulk dielectric & of an excited state ‖$j_e$$m_e$〉 appears to depend on the magnetic & is derived, and from the rotational symmetry with respect to the surface normal it is found &. A general expression for the fluorescent radiation field in the far zone is then derived, which incorporates the polarization properties of the fluorescence, as they are modified by the presence of the dielectric. It is shown that the angular distribution of the emitted intensity depends strongly on ε(ω), and it is pointed out how information about the substrate, e.g., ε(ω), can be extracted from the temporal statistical behavior of the emitted photons. It is emphasized that the major surface effects are purely geometrical, despite the essential quantum nature of the problem.

• Received 26 June 1987

DOI:https://doi.org/10.1103/PhysRevA.37.761