Advanced Photonics Nexus
Light-shift suppression in an optically pumped magnetometer via dual-frequency optical pumping
Huanyu Zhou, J Q Li, Yi Zhang, Shuo Sun, Rongtong Zhu, Yan Xuan, Pengcheng Du, Zhuangsheng Zhu
Abstract
The light shift represents a major source of measurement error and system noise in optically pumped atomic magnetometers (OPAMs). Tuning the laser frequency to a specific value is a common and effective approach to suppressing light shift in many optical-pumping systems. However, when this method is applied to OPAMs, a significant issue arises: at the zero-light-shift frequency, the magnetometer’s sensitivity decreases markedly. Consequently, it is not possible to optimize simultaneously both the measurement accuracy affected by the light shift and the overall sensitivity of the magnetometer. To address this contradiction, the underlying mechanism was analyzed using the theory of light absorption and the principles governing light–atom interactions, leading to the proposal of a dual-frequency optical-pumping scheme. Experimental results demonstrate that this approach can suppress the light shift by more than 95% while maintaining the optimal sensitivity of the OPAM. The proposed dual-frequency scheme can also be extended to other circularly polarized optical-pumping systems, thereby facilitating both the enhancement of OPAM performance and its practical deployment in real-world applications.