Practical primary thermometry via alkali-metal-vapour Doppler broadening

TL;DR

This paper demonstrates a practical primary thermometry method using alkali-metal vapour Doppler broadening, achieving sub-kelvin accuracy and high absorption fit precision in a simple setup, with potential for portable applications.

Contribution

It presents a novel, practical approach to primary thermometry using alkali-metal vapour Doppler broadening with high accuracy and simplicity.

Findings

Achieved sub-kelvin temperature accuracy.

Attained absorption fit residuals below 0.05%.

Demonstrated potential for portable thermometry devices.

Abstract

Doppler-broadening thermometry (DBT) can be used as a calibration-free primary reference suitable for practical applications, e.g. reliably measuring temperatures over long periods of time in environments where sensor retrieval is impractical. We report on our proof-of-concept investigations into DBT with alkali metal vapour cells, with a particular focus on both absorption and frequency accuracy during scans. We reach sub-kelvin temperature accuracy, and experimental absorption fit residuals below $0.05\,\%$, in a simple setup. The outlook for portable, practical devices is bright, with clear prospects for future improvement.