Atomic magnetometers based on absorption or polarization rotation of light in an alkali vapor have recently demonstrated sensitivities rivaling those of superconducting quantum interference devices (SQUIDs). Miniaturization of such devices containing vapor cells fabricated with micro electro mechanical (MEMS) technology has been the focus of development for the better part of the last decade. In this paper, we describe a portable magnetometery system with a sensitivity below 50 fT/rt-Hz at 50 Hz. The atomic magnetometer consists of a microfabricated sensor head that is fiber coupled to a control module consisting of a laser and electronics. We describe the construction of this system and present the results of sensitivity measurements with an emphasis on identifying and characterizing the source of 1/f (flicker) noise. This portable magnetometer system was developed to measure of Magnetocardiograms (MCG)of healthy human subjects inside a shielded environment.
Proceedings Title: Proc. 2010 IEEE Intl. Freq. Cont. Symp.
Conference Dates: June 1-4, 2010
Conference Location: Newport Beach, CA
Pub Type: Conferences
1/f noise, atomic magnetometer, flicker noise, high-sensitivity magnetometry, low frequency noise, magnetometry, MEMS, MOEMS, optical magnetometer, optical MEMS, SQUIDs