Abstract

Photons created in free space change in nature when interacting with even the simplest of linearly polarizable media. There is a sense in which this transformation characteristically involves the effects of squeezing as well as scattering. The field fluctuations present in the media or their vicinity may, as a result, differ dramatically from zero-point fluctuations in free space. Such altered fluctuation properties are observable, for example, through the inhibition or enhancement of the spontaneous emission rates of excited probe atoms. Not all the effects that have been discussed in connection with squeezing are observable, however. Because interactions with polarizable media can be described by means of mode expansions for which the photon occupation numbers are conserved, they do not lead to qualitative changes in the counting statistics of photoabsorption processes. The field of a dielectric illuminated by a coherent laser beam, for example, yields Poisson photon counting statistics everywhere. We shall discuss other experiments bearing on field fluctuations in dynamic models of polarizable media as well as passive ones.

© 1987 Optical Society of America