Quantum radiation of a harmonic oscillator near the planar dielectric-vacuum interface

A harmonic oscillator interacting with the electromagnetic field in the vicinity of the planar dielectric-vacuum interface has been analyzed. The electromagnetic field is described in terms of Carniglia-Mandel modes (triple-wave modes) which take into account proper boundary conditions at the interface. Exact resolvent functions, which determine the solution of the initial-value problem for the oscillator and the electromagnetic field, have been obtained. These functions give frequency shifts and decay times for oscillator excitations. In most cases, when the oscillator approaches the interface, its excitation decay time decreases. Radiative frequency shifts have been calculated and interpreted in terms of the coupling with the Carniglia-Mandel photons. Outgoing photons, i.e., photons characterized by the outgoing waves and the outgoing wave vectors, have been used for a description of angular radiation intensity patterns. Some results for the radiative damping and the radiation angular distribution are equivalent to the classical ones, however, they get a new quantum interpretation.