Absolute absorption and dispersion of a rubidium vapour in the hyperfine Paschen-Back regime

TL;DR

This study measures the absolute absorption and dispersion of rubidium vapour in high magnetic fields, revealing the hyperfine Paschen-Back regime, using a microfabricated cell and numerical modeling for validation.

Contribution

It provides the first detailed experimental and theoretical analysis of rubidium vapour in the hyperfine Paschen-Back regime at fields up to 0.6 T.

Findings

Identification of the hyperfine Paschen-Back regime above 0.33 T

Excellent agreement between experimental data and numerical susceptibility calculations

Demonstration of a compact microfabricated vapour cell for high-field measurements

Abstract

Here we report on measurements of the absolute absorption and dispersion properties of an isotopically pure 87Rb vapour for magnetic fields up to and including 0.6 T. We discuss the various regimes that arise when the hyperfine and Zeeman interactions have different magnitudes, and show that we enter the hyperfine Paschen- Back regime for fields greater than 0.33 T on the Rb D2 line. The experiment uses a compact 1 mm3 microfabricated vapour cell that makes it easy to maintain a uniform and large magnetic field with a small and inexpensive magnet. We find excellent agreement between the experimental results and numerical calculations of the weak probe susceptibility where the line positions and strengths are calculated by matrix diagonalization.