Vector magnetometry employing a rotating RF field in a single-beam optically pumped magnetometer

Abstract

Magnetic field vector information is crucial for many advanced applications, such as navigation and biomedical imaging. However, existing methods often lack high sensitivity or require complex setups. This study addresses these challenges by proposing a novel vector magnetometry method using a single-beam optically pumped magnetometer. A rotating radio-frequency field is innovatively utilized to excite atomic spin precession, enabling accurate measurement of the magnetic field direction based on scalar measurement. The method is tested through physical experiments with different magnetic field configurations to validate its performance. The experimental results demonstrate high accuracy, and achieve a magnetic field amplitude sensitivity of 800 fT/Hz${}^{1/2}$, an azimuth sensitivity of 100 $\mu$rad/Hz${}^{1/2}$, and a polar angle sensitivity of 13 $\mu$rad/Hz${}^{1/2}$. The proposed method facilitates sensor miniaturization and is suitable for applications in high magnetic field environments, such as geomagnetic field.