JING Liang^1,2, LIU Jie^1,3, GAO Jing^1,3, ZHANG Lin-bo^1,2, XU Guan-jun^1,3

(1. National Time Service Center, Chinese Academy of Science, Xi′an 710600, China;

2. University of Chinese Academy of Sciences, Beijing 100039, China;

3. Key Laboratory of Time and Frequency Primary Standards, National Time Service Center,

Chinese Academy of Science, Xi′an 710600, China)

Abstract: The fiber interferometer with length-unbalanced arms is an important part of fiber-stabilized laser which can transform frequency fluctuation of laser into phase fluctuation at the output of the interferometer. Therefore, the frequency noise of the laser can be suppressed by using the interferometer as a reference. The fiber-based Michelson interferometer applied in this experiment is studied, both theoretically and experimentally. It demonstrates that the low frequency noise of the laser can be greatly suppressed by using a Michelson interferometer with length-unbalanced fiber arms, and the control bandwidth of frequency stabilization is mainly determined by unbalanced-time-delay of the fiber interferometer.