Towards a microscopic theory of spatial confinement of light

A microscopic quantum mechanical analysis of fundamental aspects of near-field optics is presented. It is demonstrated that quantum mechanics, and not classical electromagnetics, sets the limit for the degree of spatial field localisation (compression) one can achieve. With particular reference to near-field optical microscopy at the atomic level a novel theory describing the standing-wave aspects as well as the retarded space-like interaction mechanism dominating near field electrodynamics is established and its physical ingredients discussed. The new theory indicates that only near- and far field phenomena play a fundamental role. For an atomic source middle field effects are artifacts originating in the point-particle model often used in phenomenological approaches.