Open AccessPulsed vapor cell atomic clock with a differential Faraday rotation angle detection
Author(s) -
Kemu Wang,
ZhenTing Du,
Yanyan Liu,
Zhenxin Yu,
Shubin Yan,
Tao Liu,
Ruifang Dong,
Shougang Zhang
Publication year - 2021
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.440524
Subject(s) - optics , faraday effect , physics , laser , relative intensity noise , noise (video) , faraday rotator , photodetector , materials science , semiconductor laser theory , magnetic field , quantum mechanics , artificial intelligence , computer science , image (mathematics)
Laser intensity noise is one of the main limiting factors in pulsed vapor cell clocks. To reduce the contribution of the laser intensity noise to detection signal in the pulsed optically pumped atomic clock, a scheme based on the differential Faraday rotation angle is proposed. Theoretically, the Ramsey fringes, the sensitivity of clock frequency to laser intensity fluctuation and the signal to noise ratio for absorption, differential, and Faraday rotation angle methods are calculated and compared. Using a Wollaston prism rotated 45°relative to the incident polarization, and two photodetectors, Ramsey fringes of three detection methods are obtained simultaneously. In the proposed scheme, the long-term Faraday rotation angle fluctuation is 0.66% at 30000s, which is much smaller than fluctuation of traditional absorption signal 3.9% at 30000s. And the contribution of laser intensity noise to clock instability is also reduced. Using optimized photodetector with high common mode rejection ratio, a better performance should be expected. This proposed scheme is attractive for the development of high performance vapor clock based on pulsed optically pumped.