Slow light in flight imaging

TL;DR

This paper demonstrates direct visualization of slow light propagation at the single-photon level using in-flight imaging with a specialized camera, revealing pulse compression, dispersion, and group velocity effects in rubidium vapor.

Contribution

It introduces a novel method combining light-in-flight imaging with single-photon detection to study slow light phenomena in real-time.

Findings

Visualized spatial pulse compression and dispersion effects.

Measured single-photon fractional delays greater than 1.

Demonstrated direct observation of group velocity at the single-photon level.

Abstract

Slow-light media are of interest in the context of quantum computing and enhanced measurement of quantum effects, with particular emphasis on using slow-light with single photons. We use light-in-flight imaging with a single photon avalanche diode camera-array to image in situ pulse propagation through a slow light medium consisting of heated rubidium vapour. Light-in-flight imaging of slow light propagation enables direct visualisation of a series of physical effects including simultaneous observation of spatial pulse compression and temporal pulse dispersion. Additionally, the single-photon nature of the camera allows for observation of the group velocity of single photons with measured single-photon fractional delays greater than 1 over 1 cm of propagation.