515.66km实地光纤链路级联时频传递的高精度时延校准  

High-Precision Time Calibration for Cascaded Time-Frequency Transmission of 515.66 km Long Field Optical Fiber Links

作　　者：金志成 薛申辉 徐致远 杨飞[1,4] 应康[1,4] 桂有珍[1,3,5] Jin Zhicheng;Xue Shenhui;Xu Zhiyuan;Yang Fei;Ying Kang;Gui Youzhen(Wang Zhijiang Innovation Center for Laser,Aerospace Laser Technology and System Department,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Beijing Satellite Navigation Center,Beijing 100094,China;Key Laboratory for Quantum Optics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Science,Shanghai 201800,China;Key Laboratory of Space Laser Communication and Detection Technology,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院上海光学精密机械研究所空天激光技术与系统部王之江激光创新中心,上海201800 [2]北京卫星导航中心,北京100094 [3]中国科学院上海光学精密机械研究所量子光学重点实验室,上海201800 [4]中国科学院上海光学精密机械研究所空间激光传输与探测技术重点实验室,上海201800 [5]中国科学院大学材料与光电研究中心,北京100049

出　　处：《中国激光》2024年第22期154-161,共8页Chinese Journal of Lasers

基　　金：国家自然科学基金(12293033,62175246);上海自然科学基金(22ZR1471100);科技创新2030—“量子通信与量子计算机”重大项目(2021ZD0300701);中国科学院青年创新促进会(YIPA2019251)。

摘　　要：基于波分复用和时延波动的光学补偿方案,实现北京-廊坊-保定全长515.66 km的实地光纤链路中的时间频率信号长距离级联传递,实现长距离链路1 PPS(pulse per second)时间信号传输时延精确校准。在平均时间为1 s时,100 MHz频率信号的级联传输的附加不稳定度为6.49×10^(-14),在平均时间为10000 s时为5.22×10^(-17)。在平均时间为1 s时,1 PPS时间信号的附加不稳定度为2.97×10^(-11),在平均时间为400 s时为2.46×10^(-12)。515.66 km实地链路1 PPS级联传输时延的校准值和实测值之差仅为29.90 ps,单向传输时延的不确定度为9.49 ps。这是国内近期在超过500 km实地链路光纤时频传递系统中实现优于50.00 ps的时间同步准确度的研究。该工作为长距离实际光纤链路中时延精确校准和高精度精确时间同步需求提供可行的解决方案。Objective To realize high-precision time-frequency transmission within a territory,the performance of ultra-long distance field links needs to be verified.In the case of the fiber time-frequency transmission of ultra-long links,optical power attenuation and cumulative phase noise increase with increasing link length,resulting in a decrease in compensation bandwidth and noise rejection ratio.Multistage cascade compensation is an effective solution,and introducing more cascaded transmission is the key to building a wide-area optical fiber time-frequency transmission network.For many applications that require a high time synchronization accuracy,it is necessary to know the exact delay value between the two sides to be synchronized while obtaining a stable time signal.Therefore,delay calibration and evaluation of the delay uncertainty of the optical fiber time-frequency transmission system are essential.This paper reports the realization of time-frequency cascade transmission and accurate delay calibration over a 515.66 km metro fiber link.Methods A two-stage cascade design is adopted for the high-precision time-frequency simultaneous transmission system.The system is based on a dual-wavelength noise suppression scheme with optical compensation as the core,in which the time and frequency signals are co-transmitted by a wavelength division multiplexing(WDM)scheme.The structure and implementation of each level of synchronous transmission system are the same.Therefore,we consider the first level as an example.The 100 MHz frequency signal reaches 1 GHz frequency signal after 10 frequency doubling,and then is modulated by the light wave signal with wavelength of fiber channel C35 through the transmitter.The signal-to-noise ratio of transmission can be effectively improved by adopting a higher frequency.Concurrently,1 PPS(pulse per second)time signal at the transmitting end is modulated by the optical wave signal of fiber channel C34 and entered into the optical fiber link using WDM technology.After reaching the receiving

关 键 词：时频同传 波分复用 光学补偿 时延校准 

分 类 号：O439[机械工程—光学工程]