Abstract
We describe a magnetic gradiometer that operates at finite fields and uses an intense pulsed laser to polarize a atomic ensemble and a compact vertical-cavity surface-emitting laser probe laser to detect paramagnetic Faraday rotation in a single multipass cell. We report differential magnetic sensitivity of , corresponding to gradiometer sensitivity of with a baseline, over a broad dynamic range, including Earth’s field magnitude and a common-mode rejection ratio higher than . We also observe a nearly quantum-noise-limited behavior of the gradiometer by comparing the experimental standard deviation of the estimated frequency difference against the Cramér-Rao lower bound in the presence of white photon shot-noise, atomic spin noise, and diffusion.
- Received 15 December 2021
- Revised 24 May 2022
- Accepted 8 July 2022
- Corrected 25 August 2022
DOI:https://doi.org/10.1103/PhysRevApplied.18.L021001
© 2022 American Physical Society
Physics Subject Headings (PhySH)
Corrections
25 August 2022
Correction: A proof cycle change to the author order was not implemented correctly and has now been set right.