Voigt transmission windows in optically thick atomic vapours: a method to create single-peaked line centre filters

Briscoe, Jack D; Logue, Fraser D; Pizzey, Danielle; Wrathmall, Steven A; Hughes, Ifan G

Abstract

Cascading light through two thermal vapour cells has been shown to improve the performance of atomic filters that aim to maximise peak transmission over a minimised bandpass window. In this paper, we explore the atomic physics responsible for the operation of the second cell, which is situated in a transverse (Voigt) magnetic field and opens a narrow transmission window in an optically thick atomic vapour. By assuming transitions with Gaussian line shapes and magnetic fields sufficiently large to access the hyperfine Paschen–Back regime, the window is modelled by resolving the two transitions closest to line centre. We discuss the validity of this model and perform an experiment which demonstrates the evolution of a naturally abundant Rb transmission window as a function of magnetic field. The model results in a significant reduction in two-cell parameter space, which we use to find theoretical optimised cascaded line centre filters for Na, K, Rb and Cs across both D lines. With the exception of Cs, these all have a better figure of merit than comparable single cell filters in literature. Most noteworthy is a Rb-D2 filter which outputs >92% of light through a single peak at line centre, with maximum transmission 0.71 and a width of 330 MHz at half maximum.

Citation

Briscoe, J. D., Logue, F. D., Pizzey, D., Wrathmall, S. A., & Hughes, I. G. (2023). Voigt transmission windows in optically thick atomic vapours: a method to create single-peaked line centre filters. Journal of Physics B: Atomic, Molecular and Optical Physics, 56(10), Article 105403. https://doi.org/10.1088/1361-6455/acc49c

• Journal Article Type: Article
• Acceptance Date: Mar 15, 2023
• Online Publication Date: Apr 21, 2023
• Publication Date: May 28, 2023
• Deposit Date: Aug 16, 2023
• Publicly Available Date: Aug 16, 2023
• Journal: Journal of Physics B: Atomic, Molecular and Optical Physics
• Print ISSN: 0953-4075
• Electronic ISSN: 1361-6455
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 56
• Issue: 10
• Article Number: 105403
• DOI: https://doi.org/10.1088/1361-6455/acc49c
• Keywords: Condensed Matter Physics; Atomic and Molecular Physics, and Optics
• Public URL: https://durham-repository.worktribe.com/output/1719395