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arXiv · 1202.5019

Optical Magnetometer Array for Fetal Magnetocardiography

Robert Wyllie·Matthew Kauer·Ronald T. Wakai·Thad G. Walker
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Abstract

We describe an array of spin-exchange relaxation free optical magnetometers designed for detection of fetal magnetocardiography (fMCG) signals. The individual magnetometers are configured with a small volume with intense optical pumping, surrounded by a large pump-free region. Spin-polarized atoms that diffuse out of the optical pumping region precess in the ambient magnetic field and are detected by a probe laser. Four such magnetometers, at the corners of a 7 cm square, are configured for gradiometry by feeding back the output of one magnetometer to a field coil to null uniform magnetic field noise at frequencies up to 200 Hz. Using this array, we present the first measurements of fMCG signals using an atomic magnetometer.

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Robert Wyllie, Matthew Kauer, Ronald T. Wakai, Thad G. Walker. 2012-02-22. Optical Magnetometer Array for Fetal Magnetocardiography. https://doi.org/10.1364/ol.37.002247

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