Affiliation:
1. Hefei National Laboratory
2. Hangzhou Institute of Extremely-Weak Magnetic Field Major National Science and Technology Infrastructure
Abstract
An optical pumping scheme is proposed for reducing the gradient of electron spin polarization and suppressing light source noise in a spin-exchange relaxation-free magnetometer. This is achieved by modulating only the phase of a narrow-linewidth pump light field with external Gaussian noise. Compared to the absence of phase modulation, the uniformity of electron spin polarization was improved by over 40%, and the light-frequency noise suppression ratio of the magnetometer was enhanced by 4.3 times. Additionally, the response of the magnetometer was increased by 54%, resulting in a sensitivity of 0.34 fT/Hz1/2 at 30 Hz. The applicability of this scheme can extend to other optical pumping experiments involving large atom ensembles requiring uniform electron spin polarization distribution, which is beneficial for developing ultra-high sensitivity and high stability magnetometers essential for magneto-cardiography and magneto-encephalography research applications.
Funder
National Natural Science Foundation of China
Innovation Program for Quantum Science and Technology
Postdoctoral Fellowship Program of China Postdoctora Science Foundation
Natural Science Foundation of Zhejiang Province
China Postdoctoral Science Foundation