• Chinese Optics Letters
  • Vol. 23, Issue 4, 041404 (2025)
Xinxing Guo1, Bo Liu1, Shaoshao Yu1, Qian Jing2..., Jiang Chen1, Lin Wu1, Tao Liu1,3,*, Ruifang Dong1,3,** and Shougang Zhang1,3,***|Show fewer author(s)
Author Affiliations
  • 1Key Laboratory of Time Reference and Applications, National Time Service Center, Chinese Academy of Sciences, Xi’an 710600, China
  • 2School of Science, Xi’an Shiyou University, Xi’an 710065, China
  • 3School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing 100049, China
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    DOI: 10.3788/COL202523.041404 Cite this Article Set citation alerts
    Xinxing Guo, Bo Liu, Shaoshao Yu, Qian Jing, Jiang Chen, Lin Wu, Tao Liu, Ruifang Dong, Shougang Zhang, "Time transfer over a 2061 km telecommunication fiber-optic network with single-fiber and two-wavelength approach," Chin. Opt. Lett. 23, 041404 (2025) Copy Citation Text show less

    Abstract

    In this paper, we demonstrate the single-fiber and two-wavelength time transfer (SFTWTT) over a 2061 km field fiber loop-back link network with a synchronous wavelength-division and time-division multiplexing access (WD-TDMA). This system utilizes wavelength-division multiplexing to avoid the impact of backscatter. In order to achieve high-precision time transfer, time-division multiplexing access is employed. This approach facilitates multiple bidirectional comparisons between local and remote devices. A digital phase-locked loop (PLL), which matches the bandwidth of the transfer system, and precision temperature control technology have been proposed to enhance the high stability of the fiber-optic time and frequency transfer system. The first on-site high-precision fiber-optic time transfer system exceeding 2000 km has been validated. Experimental results show that the stabilities of 5.6 ps@1 s and 3.1 ps@40,000 s can be achieved. The precision of time transfer over a 2061 km fiber-optic network, employing a single-fiber and two-wavelength approach, has been significantly enhanced. This study presents an average time difference of 52 ps across the distance, with a system uncertainty budgeted at 41.8 ps. This achievement signifies a substantial advancement in the realms of stability and reach for optical fiber time transfer, facilitating the development of a high-precision ground-based time service system.
    TimingAccuracy=InitialAccuracy×T1+0.5×Aging×(T12).

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    uSFP,total=j=129uSFP,j2+k=129uSFP,k22=29×102+29×102238.

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    Xinxing Guo, Bo Liu, Shaoshao Yu, Qian Jing, Jiang Chen, Lin Wu, Tao Liu, Ruifang Dong, Shougang Zhang, "Time transfer over a 2061 km telecommunication fiber-optic network with single-fiber and two-wavelength approach," Chin. Opt. Lett. 23, 041404 (2025)
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