Developing a testbed for optically pumped magnetometers

Highly precise and accurate magnetic field sensing finds real-world applications in non-destructive testing [1], bio-medical imaging [2], positioning and navigation [3], and transient electromagnetic measurements [4]. Here we present our work towards an experimental test platform for such sensors based on optically pumped magnetometry. An atomic vapor cell containing Cs-133 is heated to 80°C and spin-polarized via a VCSEL-laser, which is frequency stabilized on the D1-line at 895 nm. The cell is surrounded by three pairs of Helmholtz coils and a mu-metal (permalloy) shield. After optically polarizing the atomic sample, we measure its Larmor precession under the i1nfluence of a known magnetic field. We aim to test the feasibility of uncoated, paraffin-coated, and buffer-gas cells, enabling a direct comparison of their operational usability. Future work will be application-driven and include simplification, ruggedization, and miniaturization of the setup and finding a decent trade-off between sensitivity and dynamic range.

[1] S. Youssef, Journal of Nondestructive Testing 21, 19390 (2016)

[2] P. K. Mandal, Front. Comput. Neurosci. 12 (2018)

[3] A. J. Canciani, AFIT, Dissertation, https://scholar.afit.edu/etd/251, (2016)

[4] A. Chwala, SEG Technical Program, 779-783 (2010)