Absorption spectroscopy and Stokes polarimetry in a $^{87}$Rb vapour in the Voigt geometry with a 1.5 T external magnetic field

TL;DR

This paper provides a detailed spectroscopic analysis of a $^{87}$Rb vapour in a 1.5 T magnetic field using Stokes polarimetry, demonstrating high-precision measurements and modeling in the Voigt geometry.

Contribution

The study introduces a comprehensive theoretical and experimental framework for analyzing high-field atomic vapour spectra with precise parameter extraction.

Findings

Excellent agreement between experiment and theory with ~1.5% RMS error.

Successful extraction of magnetic field strength and polarization angle.

Quantification of birefringence effects on optical rotation signals.

Abstract

We present a detailed spectroscopic investigation of a thermal $^{87}$Rb atomic vapour in a magnetic field of 1.5~T in the Voigt geometry. We fit experimental spectra for all Stokes parameters with our theoretical model \textit{ElecSus} and find very good quantitative agreement, with RMS errors of $\sim 1.5$\% in all cases. We extract the magnetic field strength and the angle between the polarisation of the light and the magnetic field from the atomic signal, and we measure the birefringence effects of the cell windows on the optical rotation signals. This allows us to carry out precise measurements at a high field strength and arbitrary geometries, allowing further development of possible areas of application for atomic magnetometers.