Hawking spectrum for a fiber-optical analog of the event horizon

TL;DR

This paper calculates the Hawking radiation spectrum in a fiber-optical system mimicking an event horizon, revealing it peaks at group-velocity horizons and nearly vanishes at phase horizons, providing insights for laboratory analogs.

Contribution

It presents the first detailed calculation of Hawking radiation spectrum in a fiber-optical analog, highlighting the conditions for observable radiation in experiments.

Findings

Hawking radiation peaks at group-velocity horizons.

Radiation nearly vanishes at phase horizons.

Experimental conditions for observing Hawking radiation are identified.

Abstract

Hawking radiation has been regarded as a more general phenomenon than in gravitational physics, in particular in laboratory analogs of the event horizon. Here we consider the fiber-optical analog of the event horizon, where intense light pulses in fibers establish horizons for probe light. Then, we calculate the Hawking spectrum in an experimentally realizable system. We found that the Hawking radiation is peaked around group-velocity horizons in which the speed of the pulse matches the group velocity of the probe light. The radiation nearly vanishes at the phase horizon where the speed of the pulse matches the phase velocity of light.