%0 Journal Article
%T Optical Magnetometer Array for Fetal Magnetocardiography
%A Robert Wyllie
%A Matthew Kauer
%A Ronald T. Wakai
%A Thad G. Walker
%J Physics
%D 2012
%I arXiv
%R 10.1364/OL.37.002247
%X 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.
%U http://arxiv.org/abs/1202.5019v1