Low-drift Zeeman shifted atomic frequency reference

• Published in: arXiv.org
• Main Authors: Reed, D J, Šibalić, N, Whiting, D J, Kondo, J M, Adams, C S, Weatherill, K J
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 30.08.2018
• Subjects: Cesium; Drift; Magnetic fields; Magnetism; Permanent magnets; Physics - Atomic Physics; Rubidium; Tuning; Upper bounds; Vapors; Zeeman effect
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1804.07928

We present a simple method for producing a low-drift atomic frequency reference based upon the Zeeman effect. Our Zeeman Shifted Atomic Reference `ZSAR' is demonstrated to have tens of GHz tuning range, limited only by the strength of the applied field. ZSAR uses Doppler-free laser spectroscopy in a thermal vapor where the vapor is situated in a large, static and controllable magnetic field. We use a heated \(^{85}\)Rb vapor cell between a pair of position-adjustable permanent magnets capable of applying magnetic fields up to 1 T. To demonstrate the frequency reference we use a spectral feature from the Zeeman shifted D1 line in \(^{85}\)Rb at 795 nm to stabilize a laser to the 7S\(_{1/2}\) \(\longrightarrow\) 23P\(_{1/2}\) transition in atomic cesium, which is detuned by approximately 19 GHz from the unperturbed Rb transition. We place an upper bound on the stability of the technique by measuring a 2.5 MHz RMS frequency difference between the two spectral features over a 24 hour period. This versatile method could be adapted easily for use with other atomic species and the tuning range readily increased by applying larger magnetic fields.