摘要
在长距离高精度光纤时间同步系统中,为了减少后向反射光与光纤色散对传输精度的影响,本文在双波长光纤时间同步传输方法之上,提出了一种具有色散误差修正功能的双波长光纤时间同步传输方法.以自行研制的工程样机在长度约为800 km的实验室光纤链路上和1085 km的实地光纤链路上进行了实验测试,也是国内首次实现千公里级实地光纤时间同步传输.在实验室光纤链路上,测得传输链路色散补偿后的色散时延误差为10 ps,时间同步标准差为5.7 ps,稳定度为1.12 ps@105 s,不确定度为18.4 ps.在实地光纤链路上,测得传输链路色散补偿后的色散时延误差为60 ps,时间同步标准差为18 ps,稳定度为5.4 ps@4×10^(4) s,不确定度为63.5 ps.
To reduce the influence of fiber dispersion on accuracy of fiber-based time synchronization,a method of dispersion-error corrected dual-wavelength time synchronization is proposed in this paper.Specificlly,the method is to measure the dispersion coefficient of the fiber link,and then input it to each remote terminal,the time delay error caused by the fiber dispersion is eliminated through the delay phase controller.With the selfdeveloped engineering prototypes,the experimental verifications are subsequently made both in laboratory and real field.Before the test,16 devices of time synchronization are connected in series for calibration.The time synchronization system is able to keep delay difference within±15 ps after being calibrated.In the laboratory,the experimental setup is built by cascading 16 rolls of 50km-long fiber coils,and the total length of the fiber link is 800 km.The experimental results show that the dispersion coefficient of 800 km fiber link is 13.36 ps/(km·nm),and the delay error caused by dispersion is maintained within 10 ps after correction.The stability of the time transfer is 5.7 ps in standard deviation and the time deviation is 1.12 ps at an averaging time of 100000 s.In the real field test,a 1085-km-long field fiber link is utilized,along which 16 self-developed time-frequency transceiversare set at the cascaded fiber-optic stations.After being corrected with a dispersion coefficient of 16.67 ps/(km·nm)for 1085 km urban fiber link,the time transfer is demonstrated to have a dispersion-caused delay error of 60 ps.The experimental results show that the time standard deviation is 18 ps and the time transfer instability is 9.2 ps at an averaging time of 1 s and 5.4 ps at an averaging time of 40000 s.Finally,the time uncertainty of 800-km-long laboratory optical fiber link and 1085-km-long urban optical fiber link are evaluated,and the time uncertainty is 18.4 ps and 63.5 ps,respectively.This work paves the way for constructing the time synchronization fiber network in China.To further red
作者
陈法喜
赵侃
李博
刘博
郭新兴
孔维成
陈国超
郭宝龙
刘涛
张首刚
Chen Fa-Xi;Zhao Kan;Li Bo;Liu Bo;Guo Xin-Xing;Kong Wei-Cheng;Chen Guo-Chao;Guo Bao-Long;Liu Tao;Zhang Shou-Gang(Xidian University,Xi’an 710071,China;National Time Service Centre,Chinese Academy of Sciences,Xi’an 710600,China;University of Chinese Academy of Sciences,Beijing 100039,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2021年第7期63-72,共10页
Acta Physica Sinica
基金
国家重点研发计划(批准号:2016YFF0200200)
国家自然科学基金(批准号:91636101,91836301,11803041)
中国科学院战略先导B专项(批准号:XDB21000000)
广东省重点领域研发计划(批准号:2018B030325001)资助的课题.
关键词
光纤光学
时间同步
同步网络
fiber link
time synchronization
synchronization network
