Experimental and theoretical characterisation of Stokes polarimetry of the potassium D1 line with neon buffer gas broadening

TL;DR

This paper combines experimental measurements and theoretical modeling to analyze how neon buffer gas affects Stokes polarimetry of potassium D1 line, improving understanding of atom-light interactions in buffer-gas environments.

Contribution

It introduces the first application of ElecSus to model buffer gas effects on potassium D1 line polarimetry, validated with experimental data up to 1.2 kG magnetic fields.

Findings

Buffer gas influences Stokes parameters significantly.

Theoretical model accurately predicts experimental spectra.

Enhanced understanding of atom-light interactions with buffer gases.

Abstract

This study presents a comprehensive experimental and theoretical characterisation of Stokes polarimetry in potassium (K) vapour on the D1 line. Measurements were performed in the weak-probe regime, investigating the influence of neon buffer gas in the presence of an applied magnetic field in the Faraday geometry. While previous Stokes polarimetry studies in alkali-metal vapours have been conducted, the specific effects of buffer gas-induced broadening and shifts on the observed Stokes parameters remained largely underexplored. Here, experimental measurements of absolute absorption and dispersion were compared with a theoretical model for the electric susceptibility of the vapour, calculated using the established software package $ElecSus$. This work marks the first application of $ElecSus$ to model buffer gas polarimetry of the potassium D1 line, with validation performed against experimental spectra for magnetic fields up to 1.2 kG. Our findings provide new insight into how the presence of buffer gas influences the observed Stokes parameters, thereby enhancing the predictive capabilities of theoretical frameworks for atom-light interactions in buffer-gas environments.