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Microfabricated Optically Pumped Magnetometers


We are developing microfabricated high-performance atomic magnetometers for magnetic anomaly detection, nuclear magnetic resonance and biomagnetics.


Fiber magnetometer

The sensors are based on a heated sample of alkali atoms, which are spin-polarized with a polarized light field. Sensitivities below 20 fT/rtHz are achieved, competitive with SQUID-based magnetic sensors, but without the need for cooling to cryogenic temperatures. The sensors are being used in applications such as low-field nuclear magnetic resonance and the measurement of weak magnetic fields produced by the human body.

Major Accomplishments

High-performance magnetometers:

J. Kitching, "Chip Scale Atomic Devices," Applied Physics Reviews, vol. 5, p. 031302, 2018.

D. Sheng, A. R. Perry, S. P. Krzyzewski, S. Geller, J. Kitching, and S. Knappe, "A microfabricated optically-pumped magnetic gradiometer," Applied Physics Letters, vol. 110, p. 031106, 2017

H. Korth, K. Strohbehn, F. Tejada, A. G. Andreou, J. Kitching, S. Knappe, S. J. Lehtonen, S. M. London, and M. Kafel, "Miniature atomic scalar magnetometer for space based on the rubidium isotope 87Rb," Journal of Geophysical Research: Space Physics, vol. 121, p. doi:10.1002/2016JA022389., 2016

S. Knappe, O. Alem, D. Sheng, and J. Kitching, "Microfabricated Optically-Pumped Magnetometers for Biomagnetic Applications," Journal of Physics: Conference Series, vol. 723, p. 012055, 2016

M. P. Ledbetter, C. W. Crawford, D. E. Wemmer, A. Pines, S. Knappe, J. Kitching, and D. Budker, "Detection of J-coupling using an atomic magnetometer," US 9,140657 B2, September 22, 2015, 2015.

O. Alem, T. Sander-Thoemmes, R. Mhaskar, J. LeBlanc, H. Eswaran, U. Steinhoff, Y. Okada, J. Kitching, L. Trahms, and S. Knappe, "Fetal magnetocardiography measurements with an array of microfabricated optically-pumped magnetometers," Physics in Medicine and Biology, vol. 60, pp. 4797-4811, 2015

R. Jiménez-Martinez, S. Knappe, and J. Kitching, "An optically-modulated zero-field atomic magnetometer with suppressed spin-exchange broadening," Rev. Sci. Instrum., pp. 045124-1 - 045124-5, 2014

R. Jiménez-Martinez, D.J. Kennedy, M. Rosenbluh, E.A. Donley, S. Knappe, S.J. Seltzer, H.L. Ring, V.S. Bajaj, and J. Kitching, "Optical hyperpolarization and NMR detection of 129Xe on a microfluidic chip," Nature Communications, pp. 1 - 6, 2014 

P.J. Ganssle, H.D. Shin, S.J. Seltzer, V.S. Bajaj, M.P. Ledbetter, D. Budker, S. Knappe, J. Kitching, and A. Pines, "Ultra-Low-Field NMR Relaxation and Diffusion Measurements Using an Optical Magnetometer," Angew. Chem. Int. Ed., pp. 9766 - 9770, 2014

O. Alem, A.M. Benison, D.S. Barth, S. Knappe, and J. Kitching, "Magnetoencephalography of Epilepsy with a Microfabricated Atomic Magnetrode," J. Neurosci., pp. 14324 - 14327, 2014

R. Mhaskar, S. Knappe, and J. Kitching, "A Low-Power, High-Sensitivity Micromachined Optical Magnetometer," Applied Physics Letters, 101, pp. 241105-1 - 241105-4, 2012

R. Jimenez-Martinez, W. C. Griffith, S. Knappe, J. Kitching, and M. Prouty, "High Bandwidth Optical Magnetometer," Journal of the Optical Society of America B, 29, pp. 3395 - 3403, 2012

R. Jimenez-Martinez, W. C. Griffith, Y. J. Wang, S. Knappe, J. Kitching, K. Smith, and M. D. Prouty, "Sensitivity Comparison of Mx and Frequency-Modulated Bell-Bloom Cs Magnetometers in a Microfabricated Cell," IEEE Transactions on Instrumentation and Measurement, 59, pp. 372 - 378, 2010

W. C. Griffith, S. Knappe, and J. Kitching, "Femtotesla atomic magnetometry in a microfabricated vapor cell," Optics Express, 18, pp. 27167 - 27172, 2010

R. Jimenez-Martinez, S. Knappe, W. C. Griffith, and J. Kitching, "Conversion of laser-frequency noise to optical-rotation noise in cesium vapor," Optics Letters, 34, pp. 2519 - 2521, 2009

W. C. Griffith, R. Jimenez-Martinez, S. Knappe, J. Kitching, and V. Shah, "Miniature atomic magnetometer integrated with flux concentrators," Applied Physics Letters, 94, 2009

V. Shah, S. Knappe, P. D. D. Schwindt, and J. Kitching, "Subpicotesla atomic magnetometry with a microfabricated vapour cell," Nature Photonics, 1, pp. 649 - 652, 2007

P. D. D. Schwindt, B. Lindseth, S. Knappe, V. Shah, J. Kitching, and L.-A. Liew, "A chip-scale atomic magnetometer with improved sensitivity using the Mx technique," Applied Physics Letters, 90, 2007

E. Hodby, E. Donley, and J. Kitching, "Differential Atomic Magnetometry Based on a Diverging Laser Beam," Applied Physics Letters, 91, (2007)

P. D. D. Schwindt, L. Hollberg, and J. Kitching, "Self-oscillating Rb magnetometer using non-linear magneto-optic rotation," Review of Scientific Instruments, 76, 2005

P. D. D. Schwindt, S. Knappe, V. Shah, L. Hollberg, J. Kitching, L. A. Liew, and J. Moreland, "Chip-scale atomic magnetometer," Applied Physics Letters, 85, pp. 6409 - 6411, 2004


J. T. Robinson, E. Pohlmeyer, M. C. Gather, C. Kemere, J. E. Kitching, G. G. Malliaras, A. Marblestone, K. L. Shepard, T. Stieglitz, and C. Xie, "Developing Next-generation Brain Sensing Technologies – A Review," IEEE Sensors Journal, pp. 1-1, 2019.

T. H. Sander, J. Preusser, R. Mhaskar, J. Kitching, L. Trahms, and S. Knappe, "Magnetoencephalography with a Chip-Scale Atomic Magnetometer," Biomedical Optics Express, 3, pp. 981 - 990, 2012

S. Knappe, T. H. Sander, O. Kosch, F. Wiekhorst, J. Kitching, and L. Trahms, "Cross-validation of microfabricated atomic magnetometers with superconducting quantum interference devices for biomagnetic applications," Applied Physics Letters, 97, pp. 133703-1 - 133703-3, 2010

Nuclear Magnetic Resonance:

T. Theis, P. Ganssle, G. Kervern, S. Knappe, J. Kitching, M. P. Ledbetter, D. Budker, and A. Pines, "Parahydrogen-enhanced zero-field nuclear magnetic resonance," Nature Physics, 7, pp. 1 - 5, 2011

M. P. Ledbetter, C. W. Crawford, A. Pines, D. E. Wemmer, S. Knappe, J. Kitching, and D. Budker, "Optical detection of NMR J-spectra at zero magnetic field," Journal of Magnetic Resonance, 199, pp. 24 - 29, 2009

M. P. Ledbetter, I. M. Savukov, D. Budker, V. Shah, S. Knappe, J. Kitching, D. J. Michalak, S. Xu, and A. Pines, "Zero-field remote detection of NMR with a microfabricated atomic magnetometer," Proceedings of the National Academy of Sciences, 105, pp. 2286 - 2290, 2008

Created March 20, 2013, Updated October 2, 2019