High-resolution atomic magnetometer-based imaging of integrated circuits and batteries

Dominic Hunter; Marcin S. Mrozowski; Stuart J. Ingleby; Timothy S. Read; Allan P. McWilliam; James P. McGilligan; Ralf Bauer; Peter D. D. Schwindt; Paul F. Griffin; Erling Riis

doi:10.1109/tim.2026.3664381

High-resolution atomic magnetometer-based imaging of integrated circuits and batteries

Dominic Hunter
, Marcin S. Mrozowski
, Stuart J. Ingleby
, Timothy S. Read
, Allan P. McWilliam
, James P. McGilligan
, Ralf Bauer
, Peter D. D. Schwindt
, Paul F. Griffin
, Erling Riis

Research output: Contribution to journal › Article › peer-review

1 Citation (Scopus)

28 Downloads (Pure)

Abstract

Optically pumped magnetometers (OPMs) have emerged as a powerful technique for high-resolution magnetic field imaging. However, achieving sub-millimeter spatial resolution at sub-picotesla sensitivities (< 1 pT/ √ Hz) remains challenging, particularly under finite-field conditions. We present a high-resolution magnetic imaging system based on a free-induction-decay (FID) OPM integrated with a two-axis scanning micromirror for automated beam steering. The double-pass optical configuration allows millimeter-scale devices under test (DUTs) to be positioned directly behind the vapor cell. This enables a standoff distance of 2.7 mm between the magnetic source and the atomic vapor, improving practical imaging resolution by increasing the amplitude of near-field magnetic signals sampled within the sensitive volume. Spatial resolution is experimentally demonstrated by imaging a custom printed circuit board (PCB) containing antiparallel copper tracks spaced 2 mm apart, with measured field maps in close agreement with Biot–Savart predictions. The OPM achieves an optimal field sensitivity of 0.5 pT/ √ Hz, demonstrating the system’s capability for high-precision magnetic field measurements. The imaging system is further validated by resolving polarity-dependent asymmetries in a bridge rectifier integrated circuit (IC) and tracking current dynamics in a ceramic battery in situ. These results highlight the potential of OPM-based systems for noninvasive diagnostics of electronic circuits and batteries.

Original language	English
Article number	9509810
Pages (from-to)	1-10
Number of pages	10
Journal	IEEE Transactions on Instrumentation and Measurement
Volume	75
DOIs	https://doi.org/10.1109/tim.2026.3664381
Publication status	Published - 13 Feb 2026

Funding

D. Hunter gratefully acknowledges funding support from a Royal Academy of Engineering UK Intelligence Community Fellowship. J. P. McGilligan gratefully acknowledges funding from a Royal Academy of Engineering Research Fellowship. This work was supported by the Engineering and Physical Sciences Research Council under grants EP/W026929/1, EP/Z533166/1, and EP/Z533178/1. T. S. Read gratefully acknowledges support by the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health under Award Number U01EB028656. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the US Department of Energy National Nuclear Security Administration under contract DENA0003525. The content of this publication is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health, Sandia National Laboratories, or US Department of Energy. The authors acknowledge funding support from INMAQS. Engineering and Physical Sciences Research Council EP/W026929/1, EP/Z533166/1, EP/Z533178/1, International Network for Micro-fabricated Atomic Quantum Sensors (INMAQS) Royal Academy of Engineering UK Intelligence Community Fellowship National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health U01EB028656, Sandia National Laboratories is a Multimission Laboratory Managed and Operated through the National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., U.S. Department of Energy National Nuclear Security Administration DENA0003525, Royal Academy of Engineering Research Fellowship

Keywords

optically pumped magnetometer
free induction decay
magnetic field imaging
MEMS scanning mirror
quantum sensing
cesium vapor
integrated circuits
battery monitoring

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10.1109/tim.2026.3664381

Hunter-etal-IEEE-TIM-2026-High-resolution-atomic-magnetometer-based-imagingAccepted author manuscript, 18.1 MBLicence: CC BY 4.0

Cite this

Hunter, D., Mrozowski, M. S., Ingleby, S. J., Read, T. S., McWilliam, A. P., McGilligan, J. P., Bauer, R., Schwindt, P. D. D., Griffin, P. F., & Riis, E. (2026). High-resolution atomic magnetometer-based imaging of integrated circuits and batteries. IEEE Transactions on Instrumentation and Measurement, 75, 1-10. Article 9509810. https://doi.org/10.1109/tim.2026.3664381

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abstract = "Optically pumped magnetometers (OPMs) have emerged as a powerful technique for high-resolution magnetic field imaging. However, achieving sub-millimeter spatial resolution at sub-picotesla sensitivities (< 1 pT/ √ Hz) remains challenging, particularly under finite-field conditions. We present a high-resolution magnetic imaging system based on a free-induction-decay (FID) OPM integrated with a two-axis scanning micromirror for automated beam steering. The double-pass optical configuration allows millimeter-scale devices under test (DUTs) to be positioned directly behind the vapor cell. This enables a standoff distance of 2.7 mm between the magnetic source and the atomic vapor, improving practical imaging resolution by increasing the amplitude of near-field magnetic signals sampled within the sensitive volume. Spatial resolution is experimentally demonstrated by imaging a custom printed circuit board (PCB) containing antiparallel copper tracks spaced 2 mm apart, with measured field maps in close agreement with Biot–Savart predictions. The OPM achieves an optimal field sensitivity of 0.5 pT/ √ Hz, demonstrating the system{\textquoteright}s capability for high-precision magnetic field measurements. The imaging system is further validated by resolving polarity-dependent asymmetries in a bridge rectifier integrated circuit (IC) and tracking current dynamics in a ceramic battery in situ. These results highlight the potential of OPM-based systems for noninvasive diagnostics of electronic circuits and batteries.",

keywords = "optically pumped magnetometer, free induction decay, magnetic field imaging, MEMS scanning mirror, quantum sensing, cesium vapor, integrated circuits, battery monitoring",

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AU - McGilligan, James P.

AU - Bauer, Ralf

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AB - Optically pumped magnetometers (OPMs) have emerged as a powerful technique for high-resolution magnetic field imaging. However, achieving sub-millimeter spatial resolution at sub-picotesla sensitivities (< 1 pT/ √ Hz) remains challenging, particularly under finite-field conditions. We present a high-resolution magnetic imaging system based on a free-induction-decay (FID) OPM integrated with a two-axis scanning micromirror for automated beam steering. The double-pass optical configuration allows millimeter-scale devices under test (DUTs) to be positioned directly behind the vapor cell. This enables a standoff distance of 2.7 mm between the magnetic source and the atomic vapor, improving practical imaging resolution by increasing the amplitude of near-field magnetic signals sampled within the sensitive volume. Spatial resolution is experimentally demonstrated by imaging a custom printed circuit board (PCB) containing antiparallel copper tracks spaced 2 mm apart, with measured field maps in close agreement with Biot–Savart predictions. The OPM achieves an optimal field sensitivity of 0.5 pT/ √ Hz, demonstrating the system’s capability for high-precision magnetic field measurements. The imaging system is further validated by resolving polarity-dependent asymmetries in a bridge rectifier integrated circuit (IC) and tracking current dynamics in a ceramic battery in situ. These results highlight the potential of OPM-based systems for noninvasive diagnostics of electronic circuits and batteries.

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KW - MEMS scanning mirror

KW - quantum sensing

KW - cesium vapor

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ER -

High-resolution atomic magnetometer-based imaging of integrated circuits and batteries

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Keywords

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