Emission characteristics from dipoles with fixed positions in Fabry-Perot cavities

Spectral characteristics of emission from Fabry-Perot cavities containing dipoles with fixed positions are calculated. It is shown that the emission characteristics can have a sensitive dependence on the precise location of the dipoles. When the dipoles have a fixed position the usual analysis of the emission in terms of the cavity transmission characteristics becomes invalid. Interference effects which lead to the spectral characteristics are then determined by the details of the interaction between the cavity reflectors and the spontaneous wavepackets emitted from the excited dipoles. Typical measured emission which resembles cavity transmission spectra actually results from averaging over many dipole positions. For dipole locations close to a cavity reflector, that is within the first-order coherence length of the spontaneous emission, total emission into all cavity modes can be either increased or decreased depending on the precise dipole location. An example of the dipole localization effects is given in the experimental emission characteristics from a semiconductor Fabry-Perot cavity