Time varying gratings model Hawking radiation

TL;DR

This paper models Hawking radiation using moving diffraction gratings, showing that optical event horizons can trap and amplify wave energy, producing a measurable, quasi-thermal quantum vacuum radiation spectrum dependent on grating profile and length.

Contribution

It introduces a novel optical analog for Hawking radiation using time-varying gratings and calculates the resulting radiation spectrum and temperature scaling.

Findings

Wave trapping at optical horizons leads to radiation emission.

The spectrum is quasi-thermal with profile-dependent features.

Emission flux scales exponentially with grating length.

Abstract

Diffraction gratings synthetically moving at trans-luminal velocities contain points where wave and grating velocities are equal. We show these points can be understood as a series of optical event horizons where wave energy can be trapped and amplified, leading to radiation from the quantum vacuum state. We calculate the spectrum of this emitted radiation, finding a quasi-thermal spectrum with features that depend on the grating profile, and an effective temperature that scales exponentially with the length of the grating, emitting a measurable flux even for very small grating contrast.