title: Optical magnetometer array for fetal magnetocardiography.
abstract: We describe an array of spin-exchange-relaxation-free optical magnetometers designed for detection of fetal magnetocardiography (fMCG). 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. We present the first measurements of fMCG signals using an atomic magnetometer.
authors: Department of Physics, University of Wisconsin–Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA.
authors: Robert
authors: R
authors: Wyllie
authors: Matthew
authors: M
authors: Kauer
authors: Ronald T
authors: RT
authors: Wakai
authors: Thad G
authors: TG
authors: Walker
mesh_terms: D005246:Feedback; D005333:Fetus / Q000502:physiology*; D060328:Magnetic Phenomena; D053798:Magnetocardiography / Q000295:instrumentation*; D055620:Optical Phenomena