On the quantum space-time structure of light

We extend the quantum theory of Time Refraction for a generic spatial and temporal modulation of the optical properties of a medium, such as a dielectric or a gravitational field. The derivation of the local Bogoliubov transformations relating the global electromagnetic modes (valid over the entire span of space and time) with the local modes (valid for the vicinity of each spatial and temporal position) is presented and used in the evaluation of vacuum photon creation by the optical modulations of the medium. We use this approach to relate and review the results of different quantum effects such as the dynamical Casimir effect, space and Time Refraction, the Unruh effect and radiation from superluminal non-accelerated optical boundaries.