Experimental Investigation on a Highly Sensitive Atomic Magnetometer

Guobin Liu, Xian-Ping Sun, 顾思洪 +2 more

Ailin Yang, Guoqing Yang, Yunfei Xu +1 more

We present an experimental and theoretical investigation of the coherent population trapping (CPT) resonance excited on the D1 line of 87 Rb atoms by bichromatic linearly polarized laser light. The experimental results show that a lin ‖ lin transition scheme is a promising alternative to the conventional circular—circular transition scheme for an atomic magnetometer. Compared with the circular light transition scheme, linear light accounts for high-contrast transmission resonances, which makes this excitation scheme promising for high-sensitivity magnetometers. We also use linear light and circular light to detect changes of a standard magnetic field, separately.

吴梓楠 Wu Zinan, 赵正钦 Zhao zhengqin, 温钟平 Wen Zhongping +5 more

Shuguang Li, Zhou Xiang, Cao Xiao-Chao +5 more

An all-optical high sensitivity atomic magnetometer is investigated and demonstrated experimentally, of which the principle is based on the interaction between laser beam and rubidium atoms in magnetic field. This interaction is dependent on the magnetic field surrounding the Rb atom cell, therefore the magnetic field information can be obtained simply by measuring the changes of the laser power transmitted through the Rb atom cell. The principle of the atomic magnetometer is analyzed and the performance of the experimental setup is investigated. The experimental result agrees well with the theoretical predictions. Furthermore, some important factors that may affect the performance of the magnetometer are discussed, and the ways to improve the sensitivity of the atomic magnetometer are also put forward.

Peng Shi, Chen Zuo, Qisong Li +1 more

Spin-exchange relaxation-free (SERF) atomic magnetometers have emerged as highly promising candidates for ultra-weak magnetic field detection, particularly in biomagnetic imaging, owing to their exceptional sensitivity, amenability to miniaturization, and near-room-temperature operation. While current miniaturized magnetometers typically employ laser chips with fixed optical power, the quantitative impact of laser power on critical performance metrics remains to be fully elucidated. This study systematically investigates the influence of laser power on sensitivity, bandwidth, and dynamic range by incorporating considerations of power broadening, saturation absorption, and noise constraints. A miniaturized probe, integrated with an actively controlled vertical-cavity surface-emitting laser (VCSEL), was developed for experimental validation. Theoretical and experimental results consistently demonstrate that as optical power increases, sensitivity exhibits a non-monotonic dependence, whereas both bandwidth and dynamic range manifest a monotonic upward trend, aligning well with theoretical simulations. The optimized sensor achieved a peak sensitivity of 16 fT/√Hz at 300 μW, while the bandwidth and dynamic range reached 230 Hz and ±5.4 nT at 500 μW, respectively. This work establishes a robust theoretical and experimental framework for the comprehensive performance optimization of laser-integrated miniaturized atomic magnetometers.

Georgios Vasilakis, Thomas W. Kornack, R. Ghosh +2 more