Photonic Band Gaps in One-Dimensionally Ordered Cold Atomic Vapors

TL;DR

This paper experimentally demonstrates high-efficiency Bragg reflection in one-dimensional cold atomic structures, revealing photonic band gaps that enable nearly 80% light reflectance, advancing control over light-matter interactions.

Contribution

The study provides the first experimental observation of photonic band gaps in cold atomic vapors with high reflectance, confirming theoretical predictions.

Findings

Achieved 80% reflectance efficiency.

Confirmed the presence of photonic band gaps.

Demonstrated control of light reflection via atomic periodicity.

Abstract

We experimentally investigate the Bragg reflection of light at one-dimensionally ordered atomic structures by using cold atoms trapped in a laser standing wave. By a fine tuning of the periodicity, we reach the regime of multiple reflection due to the refractive index contrast between layers, yielding an unprecedented high reflectance efficiency of 80%. This result is explained by the occurrence of a photonic band gap in such systems, in accordance with previous predictions.