1. A High Sensitivity Closed-Loop Spin-Exchange Relaxation-Free Atomic Magnetometer With Broad Bandwidth
- Author
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Tao Hu, Zhongyi Wu, Chun-qiao Chen, Yan Chang, Yin Zhang, Ming-kang Zhang, Xiaoyu Feng, Qingqian Guo, and Xiaodong Yang
- Subjects
Physics ,Dynamic range ,Magnetometer ,business.industry ,Relaxation (NMR) ,Superconducting magnet ,Magnetic field ,law.invention ,SQUID ,law ,Bandwidth (computing) ,Optoelectronics ,Sensitivity (control systems) ,Electrical and Electronic Engineering ,business ,Instrumentation - Abstract
Spin-exchange relaxation-free (SERF) atomic magnetometers are the promising non-cryogenic sensors to potentially replace the superconducting quantum interference device (SQUID) in the ultra-weak magnetic-field measurements. Although the SERF magnetometers have achieved a sensitivity of sub-femtotesla, the bandwidth is limited at a narrow range. In this work, we developed a closed-loop SERF magnetometer under proportional-integral (PI) control, the bandwidth could be adaptively tuned and extended above 1.2 kHz. A nearly 40-fold enhancement of the typical bandwidth was achieved in comparison with the open-loop system and the sensitivity was maintained at 15 fT/Hz1/2 from 30 Hz to 750 Hz. Moreover, the magnetic field dynamic range could also be greatly improved. This proposed atomic magnetometer with higher bandwidth, sensitivity, and dynamic range has a good prospect in developing a compact, portable, and non-cryogenic magnetic field sensor and may find more applications in biomedical, nuclear magnetic resonance, and fundamental physics research.
- Published
- 2021