Optical transmission of an atomic vapor in the mesoscopic regime

TL;DR

This paper investigates how near-resonant light transmission through a nano-cell filled with atomic vapor exhibits mesoscopic optical effects due to atomic motion and phase coherence, challenging traditional local response models.

Contribution

It introduces a non-local, size-dependent susceptibility model that accurately describes mesoscopic optical responses in atomic vapors confined in nano-cells.

Findings

Conventional dispersion theory fails to match experimental spectra.

A non-local susceptibility model aligns well with measurements.

Results enhance understanding of light-matter interactions at the mesoscopic scale.

Abstract

By measuring the transmission of near-resonant light through an atomic vapor confined in a nano-cell we demonstrate a mesoscopic optical response arising from the non-locality induced by the motion of atoms with a phase coherence length larger than the cell thickness. Whereas conventional dispersion theory -- where the local atomic response is simply convolved by the Maxwell-Boltzmann velocity distribution -- is unable to reproduce the measured spectra, a model including a non-local, size-dependent susceptibility is found to be in excellent agreement with the measurements. This result improves our understanding of light-matter interaction in the mesoscopic regime and has implications for applications where mesoscopic effects may degrade or enhance the performance of miniaturized atomic sensors.