Research on the anti-interference ability of optically pumped magnetometer

Abstract

The anti-interference ability of OPM is systematically demonstrated by theoretical analysis and experimental study in this paper. The results show that the transverse modulation mode of the single-beam OPM has the strongest anti-interference ability compared with the dual-beam OPM’s non-modulation and longitudinal modulation modes. Additionally, the OPM built with a larger linewidth cell has a stronger anti-interference ability than that with a smaller linewidth cell. Moreover, a three-axis magnetic field closed-loop control mode of the single-beam OPM is proposed to further enhance the anti-interference ability. The experimental results prove that the OPM operating at the three-axis magnetic field closed-loop mode can provide real-time feedback on the magnetic field so that the performance of the OPM remains unchanged under biased magnetic fields, and the scale factor error is stable within 0.5%. The enhancement of OPM’s anti-interference ability is significant to improve the MEG source localization accuracy of OPM-MEG systems.