CANONICAL QUANTIZATION OF LIGHT IN A LINEAR DIELECTRIC

Quantization of the macroscopic electromagnetic field via effective susceptibilities leads to inconsistencies if the medium is dispersive. A canonical quantization scheme has to take explicit account of the matter field. By introducing a simple model for the matter, we are able to resolve some of the difficulties highlighted in the recent literature. We demonstrate the fundamental significance of the electromagnetic energy flux (rather than the density) and justify the use of temporal modes of the field. Our analysis leads to an apparently unknown relationship between the group and phase velocity in a linear dielectric medium.