Pulsed optically pumped atomic clock with a medium- to long-term frequency stability of 10-15

Qian Shen; Haixiao Lin; Jianliao Deng; Yuzhu Wang

doi:10.1063/5.0006187

Pulsed optically pumped atomic clock with a medium- to long-term frequency stability of 10^-15

Rev Sci Instrum. 2020 Apr 1;91(4):045114. doi: 10.1063/5.0006187.

Authors

Qian Shen¹, Haixiao Lin¹, Jianliao Deng¹, Yuzhu Wang¹

Affiliation

¹ Key Laboratory of Quantum Optics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.

PMID: 32357681
DOI: 10.1063/5.0006187

Abstract

Herein, we report a significant improvement in the medium- to long-term frequency stability of our pulsed optically pumped (POP) vapor-cell rubidium clock. Such an achievement is established with the better control of our system and the environment. An integrated optical module, including a distributed Bragg reflector laser and an acousto-optic modulator, is developed to improve the stability of the laser. The physics package is sealed in a vacuum chamber with a vacuum of 4 × 10^-4 Pa to significantly reduce the impacts of the barometric effect. An AC-driven heater is placed much closer to the cell to enable a better temperature control. The resolution of the servo control voltage is also optimized. With all these improvements, a frequency stability of 4.7 × 10^-15 at 10⁴ s in terms of the Allan deviation is obtained. We also estimate the main noise sources that limit the frequency stability of the POP atomic clock.