Zero-point noise in a nonstationary dielectric cavity

The vacuum field in a dielectric cavity where the medium has a rapidly changing time-dependent refractive index exhibits nonclassical features that are directly related to the distortion of the vacuum fluctuations of the field. For appropriate parameters, these nonclassical effects are appreciable enough that a suitable measure of the change in the zero-point noise of the cavity field could provide a way to probe distortions of the vacuum fluctuations.