基于光纤传输的相位噪声净化与绝对一致相位同步  

Phase Noise Purification and Absolutely Consistent Phase Synchronization Based on Optical Fiber Transmission

作　　者：吴瑞 杨飞[1] 孙延光[1] 魏芳[1] 桂有珍 丁亚茜[4] 蔡海文[1,2] Wu Rui;Yang Fei;Sun Yanguang;Wei Fang;Gui Youzhen;Ding Yaqian;Cai Haiwen(Key Laboratory of Space Laser Communication and Detection Technology,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai201800,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Quantum Optics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;The 23rd Research Institute,China Electronics Technology Group Corporation,Shanghai 201900,China)

机构地区：[1]中国科学院上海光学精密机械研究所空间激光信息传输与探测技术重点实验室,上海201800 [2]中国科学院大学材料与光电研究中心,北京100049 [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]中国电子科技集团公司第二十三研究所,上海201900

出　　处：《中国激光》2021年第21期88-96,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(61875214);国家重点研发计划(2020YFC2200300);中国科学院战略性先导科技专项(XDB43000000);中国科学院青年创新促进会(YIPA2019251)。

摘　　要：相干探测应用对光纤时频同步技术提出了新的需求,在频率同步的基础上还要能保证相位同步,并且要求低相位噪声传输。为此,研究了一种具有相位噪声净化功能的光纤绝对一致相位同步系统。首先,通过电学锁相环净化频率信号的远端相位噪声,降低了1 GHz频率信号经过26 km长光纤传输后恶化的相位噪声,比如在100 kHz频率偏移处,相位噪声降低了17.0 dB。随后,通过控制时间脉冲的往返延迟和频率信号的往返相移,实现了本远端相位差的绝对一致。当系统经历关闭重启和更改光纤链路操作后,相位差的平均值表现出约2π全周期的1%的不一致性。所设计系统可以在实现频率信号的低相位噪声传输的同时较好地保证了相干性,在相干阵列探测等场景具有重要的应用价值。Objective Time and frequency synchronization technology based on optical fiber transmission method has good synchronization performance,which can meet application requirements such as clock comparison,very long baseline interference,and radar networking.However,some coherent detection applications put forward new requirements for fiber-based time and frequency synchronization technology.Phase synchronization must also be ensured based on frequency synchronization,and low phase noise transmission is required simultaneously.Phase synchronization means that no matter what changes the system experiences,the phase difference between remote sites can remain a constant value,ensuring the phase coherence of the frequency signal.But low phase noise transmission may bring uncertainty to phase synchronization.Therefore,this paper has studied a consistent fiber-optic phase synchronization system with phase noise purification function.Methods The transmitted frequency signal is input into an electrical phase-locked loop(EPLL)at the remote site.The EPLL contains an oven-controlled crystal oscillator(OCXO)with ultra-low phase noise.After completing phase lock,the phase noise of the output frequency signal will be the same as the OCXO at frequency offsets higher than the phase-locking bandwidth.Therefore,the deteriorated far-end phase noise of the frequency signal due to fiber transmission can be purified by the EPLL,realizing low phase noise transmission.Through the“round-trip delay stabilization”method,the round-trip phase difference can remain constant,while the one-way phase difference may change as long as system status changes.EPLL and the phase compensation process can bring phase uncertainties to the one-way phase difference through theoretical analysis.According to the relationship between the round-trip time delay of the time pulse and the phase difference of the frequency signal,the change value of the round-trip delay can be controlled to the even periods of the frequency signal,thereby eliminating the half-perio

关 键 词：光纤光学 光纤链路和子系统 相位同步 相位噪声 不一致性 

分 类 号：TN29[电子电信—物理电子学]