基于激光波长跟踪的高精度光纤时间传递  

High precision time transfer based on laser wavelength tracking

作　　者：陈法喜[1,2] 赵侃 李立波 郭宝龙 Chen Fa-Xi;Zhao Kan;Li Li-Bo;Guo Bao-Long(Xidian University,Xi’an 710071,China;Jinan Institute of Quantum Technology,Jinan 250101,China)

机构地区：[1]西安电子科技大学,西安710071 [2]济南量子技术研究院,济南250101

出　　处：《物理学报》2022年第23期209-218,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12003042)资助的课题.

摘　　要：时间传递不确定度是光纤时间传递系统的核心指标,商用通讯激光模块波长的不一致和波长的漂移所引入的光纤色散效应是影响时间传递不确定度的主要因素.本文提出了一种基于激光波长跟踪的高精度时间传递方法,在双向同波分时方案基础上,通过波长测量并利用双层控温保持了双向波长的长期一致性,进而大幅改善了时间传递不确定度指标,该方法在长距离光纤时间传递系统中尤其重要.为了验证该方法的可行性,在0.005,250,500,750 km不同长度的实验室光纤链路上进行了实验验证,时间同步偏差均优于5 ps,并在750 km实验室链路上实现了稳定度为4.7 ps@1 s,0.4 ps@4×10^(4) s和时间传递不确定度8.4 ps的高精度时间传递,为远距离高精度光纤时间传递工程奠定技术基础.In a high-precision optical fiber time transfer system,in order to solve the scientific problem of time transfer dispersion deviation caused by the inconsistency of the two-way laser wavelengths,a high-precision time transfer method based on laser wavelength tracking is proposed in this paper.In the two-way time comparison,the laser emitted by the local site is used as a reference,and other lasers in the system track the reference,and the difference between the two-way laser wavelengths is small enough and stable for a long time,thereby greatly reducing the time transfer deviation caused by the inconsistency of the two-way laser wavelengths.In order to verify the performance of laser wavelength tracking,a double-layer temperature controlled externally modulated laser is designed,an experimental device for automatic laser wavelength tracking is designed,and laser wavelength tracking experimental modules are developed.The results show that the standard deviation of wavelength jitter is 55 fm,and the long-term relative stability of laser wavelength tracking is better than 5 fm@1×10^(4) s,which ensures that the two laser wavelengths can remain relatively stable for a long time.In the case of long-distance fiber time transfer,by optimizing the setting value of the wavelength difference between each laser and the reference light on the link,the dispersion deviation of time transfer can be further reduced.In order to verify the feasibility of the high-precision optical fiber time transfer method based on laser wavelength tracking,a long-distance multi-station optical fiber time transfer experimental setup is built in our laboratory.The experiment is carried out in the laboratory by using 0.005,250,500,750 km optical fiber links.The experimental results obtained on 750 km link show that the time transfer deviation is better than 5 ps,the stability is 4.7 ps@1 s,0.4 ps@4×10^(4) s,and the uncertainty is 8.4 ps.In the engineering application of optical fiber time transfer,by optimizing the working sequence of the system,t

关 键 词：光纤链路 时间同步 同步网络 波长跟踪 

分 类 号：TN929.11[电子电信—通信与信息系统]