Vacuum Lightcone Fluctuations in a Dielectric

Understand

A model for observable effects of electromagnetic vacuum fluctuations is presented.

• The model involves a probe pulse which traverses a slab of nonlinear optical material with a nonzero second order polarizability.
• We argue that the pulse interacts with the ambient vacuum fluctuations of other modes of the quantized electric field, and these vacuum fluctuations cause variations in the flight time of the pulse through the material.
• The geometry of the slab of material defines a sampling function for the quantized electric field, which in turn determines that vacuum modes whose wavelengths are of the order of the thickness of the slab give the dominant contribution.