Open AccessSimultaneously improving the sensitivity and absolute accuracy of CPT magnetometer
Author(s) -
Shangqing Liang,
GuangFu Yang,
Yuanxin Xu,
Qiang Lin,
Zhiheng Liu,
Zhengxiang Chen
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.006837
Subject(s) - magnetometer , sensitivity (control systems) , optics , physics , microwave , magnetic field , larmor precession , population , noise (video) , ranging , nuclear magnetic resonance , telecommunications , electronic engineering , computer science , demography , quantum mechanics , artificial intelligence , sociology , engineering , image (mathematics)
A new method to improve the sensitivity and absolute accuracy simultaneously for coherent population trapping (CPT) magnetometer based on the differential detection method is presented. Two modulated optical beams with orthogonal circular polarizations are applied, in one of which two magnetic resonances are excited simultaneously by modulating a 3.4GHz microwave with Larmor frequency. When a microwave frequency shift is introduced, the difference in the power transmitted through the cell in each beam shows a low noise resonance. The sensitivity of 2pT/Hz @ 10Hz is achieved. Meanwhile, the absolute accuracy of ± 0.5nT within the magnetic field ranging from 20000nT to 1nT is realized.