Realizing a rapidly switched Unruh-DeWitt detector through electro-optic sampling of the electromagnetic vacuum

A new theoretical framework to describe the experimental advances in electro-optic detection of broadband quantum states, specifically vacuum, is devised. Electro-optic sampling a technique ultrafast photonics which, when transferred into domain, can be utilized resolve properties sampled state via its interaction with strong coherent probe pulse at timescales. By making use fundamental concepts from field theory on spacetime metrics, nonlinear behind effect shown equivalent stationary Unruh-DeWitt detector coupled conjugate during very short time interval. When coupling lasts for interval comparable oscillation periods detected mode (i.e., subcycle regime), virtual particles inhabiting vacuum are form real excitation. We demonstrate that this behavior rigorously translated scenario which (spectrally filtered) works as an detector, interaction-generated photons arising electromagnetic vacuum. Our analysis accurately encapsulates nature and we propose specific working regime experimentally verify existence correlations ground state.