Dual-Axis Hanle magnetometer based on atomic alignment with a single optical access

Abstract : The usual Hanle-effect magnetometers allow the measurement of two components of a very-low magnetic field using three orthogonal light beams. Here we present a scheme based on atomic alignment that requires only a single optical access for both a pump beam and a probe beam with a small angle between them. The results of experimental tests of this configuration are in close agreement with the theoretical predictions. We show that measurements of the third component should be possible by instrumentation of a partial depolarization of the pump beam. Such compact architectures open interesting perspectives for magnetometer arrays for medical imaging.