Spatially resolved spectroscopy of alkali metal vapour diffusing inside hollow-core photonic crystal fibres

TL;DR

This paper introduces a compact, all-glass vapour cell with hollow-core photonic crystal fibres that enables fast, homogeneous heating and real-time monitoring of rubidium atom diffusion through fluorescence measurements.

Contribution

It presents a novel all-glass vapour cell design that allows rapid filling, homogeneous heating, and live optical access for studying atomic diffusion inside fibres.

Findings

Fast filling times from minutes to hours.

Homogeneous heating improves diffusion analysis.

Real-time fluorescence monitoring of rubidium atoms.

Abstract

We present a new type of compact and all-glass based vapour cell integrating hollow-core photonic crystal fibres. The absence of metals, as in a traditional vacuum chamber and the much more compact geometry allows for fast and homogeneous heating. As a consequence we can fill the fibres on much faster timescales, ranging from minutes to hours. Additionally the all-glass design ensures optical access along the fibre. This allows live monitoring of the diffusion of rubidium atoms inside the hollow-core by measuring the frequency-dependent fluorescence from the atoms. The atomic density is numerically retrieved using a 5-level system of Bloch-equations.