Wang Yaxiang, Shi Tao, Zhou Weiyong, Tang JunJian, Zhou BinQuan, Jin Ge, Han Bangcheng, Zou Sheng
Opt Express. 2022 Jun 20;30(13):23587-23599. doi: 10.1364/OE.458827.
In the spin-exchange relaxation-free (SERF) magnetometer of a perpendicular pump-probe configuration, the pump and probe beam characteristics significantly affect the performance. In this paper, an efficient evaluation of optical parameters to improve the sensitivity of a miniature magnetometer has been presented. We have determined the pump light's optimal intensity and wavelength through theoretical analysis and the zero-field resonance experiments. Chirp signals are applied to measure the optical rotations at different probe intensities and frequencies. Through theoretical and experimental analysis of noise source characterization under different beam intensities and wavelengths, we demonstrate that dual-beam magnetometer performance is mainly limited by photon shot noise. Based on the optimum pump and probe beam parameters, we demonstrate magnetic field sensitivity of 6.3 fT/Hz in an Rb vapor cell filled with nitrogen gas, with an active measurement volume of 3 × 3 × 3 mm.
在垂直泵浦-探测配置的无自旋交换弛豫（SERF）磁力计中，泵浦光束和探测光束的特性会显著影响其性能。本文提出了一种有效评估光学参数以提高微型磁力计灵敏度的方法。我们通过理论分析和零场共振实验确定了泵浦光的最佳强度和波长。采用啁啾信号在不同探测强度和频率下测量光学旋转。通过对不同光束强度和波长下噪声源特性的理论和实验分析，我们证明双光束磁力计的性能主要受光子散粒噪声限制。基于最佳的泵浦光束和探测光束参数，我们在充满氮气的铷气室中实现了6.3 fT/Hz的磁场灵敏度，有效测量体积为3×3×3 mm。
