arXiv:1403.7545 · Physical Review Letters
All-Optical Vector Atomic Magnetometer
Brian Patton, E. Zhivun, D. C. Hovde, Dmitry Budker
Abstract
We demonstrate an all-optical magnetometer capable of measuring the magnitude and direction of a magnetic field using nonlinear magneto-optical rotation in cesium vapor. Vector capability is added by effective modulation of the field along orthogonal axes and subsequent demodulation of the magnetic-resonance frequency. This modulation is provided by the ac Stark shift induced by circularly polarized laser beams. The sensor exhibits a demonstrated rms noise floor of $\ensuremath{\sim}65\text{ }\text{ }\mathrm{fT}/\sqrt{\mathrm{Hz}}$ in measurement of the field magnitude and $0.5\text{ }\text{ }\mathrm{mrad}/\sqrt{\mathrm{Hz}}$ in the field direction; elimination of technical noise would improve these sensitivities to $12\text{ }\text{ }\mathrm{fT}/\sqrt{\mathrm{Hz}}$ and $10\text{ }\text{ }\ensuremath{\mu}\mathrm{rad}/\sqrt{\mathrm{Hz}}$, respectively. Applications for this all-optical vector magnetometer would include magnetically sensitive fundamental physics experiments, such as the search for a permanent electric dipole moment of the neutron.