Dual-Axis Hanle Magnetometer Based on Atomic Alignment with a Single Optical Access

Optically pumped magnetometers are serious candidates to replace SQUIDs, and thus avoid the need for cryogenics, in applications like magnetoencephalography. In building magnetometer arrays for imaging, a compact yet multiaxis architecture is highly desirable. Here the authors present a scheme based on atomic alignment that only requires one optical access point, bearing both a pump beam and a probe beam at a small angle to it, and that allows measurement of two magnetic field components. Measuring the third component should be possible via partial depolarization of the pump beam. Such a compact scheme opens interesting perspectives for magnetometer arrays for medical imaging.