基于光学时延补偿的50km光纤微波频率传递  

Microwave Frequency Dissemination via 50 km Optical Fiber Based on Optical Delay Compensation

作　　者：赵粹臣 赵文宇[1] 薛文祥[1,2] 全洪雷 闫露露 郭文阁[1] 姜海峰[1,2] 张首刚[1,2] ZHAO Cui-chen;ZHAO Wen-yu;XUE Wen-xiang;QUAN Hong-lei;YAN Lu-lu;GUO Wen-ge;JIANG Hai-feng;ZHANG Shou-gang(Key Laboratory of Time and Frequency Primary Standards,National Time Service Center,Chinese Academy of Sciences,Xi'an 710600,China;School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院国家授时中心时间频率基准重点实验室,西安710600 [2]中国科学院大学天文与空间科学学院,北京100049

出　　处：《光子学报》2020年第8期33-39,共7页Acta Photonica Sinica

基　　金：国家杰出青年科学基金(No.61825505)。

摘　　要：报道了利用50km光纤实现4.38×10^-15@1 s和2.80×10^-18@65.5×10^3s稳定度的微波频率传递的实验研究.实验系统采用多普勒噪声消除技术,通过在本地端探测往返传递的微波信号相位获得链路上的相位变化信息,并实时控制光延迟调整机构进行补偿.光延迟控制采用压电陶瓷的快速拉伸和慢速光纤温控联合方式,可实现5 ns和千赫兹带宽的光延迟控制,能够实现光纤噪声的长期高精度补偿.与电相位补偿相比,光延迟补偿受微波泄露的影响相对较小,而微波泄露影响在类似系统难以避免,因此这种方式更利于获得高稳定度的频率传递.此外,系统采用变频往返传递消除光寄生反射效应,以及色散补偿光纤减小因色散引起的调制信号衰减等措施,提高了系统的技术指标.An experimentally study on microwave frequency transfer over a 50 km long fiber was reported,which frequency instabilities reach 4.38×10^-15@1 s and 2.80×10^-18@65.5×10^3 s.By using the well-known Doppler noise cancellation method,the fiber noise was measured by comparing the phase of the signal double-passed fiber and the reference one at local site,and compensate the fiber noise with a home-made fiber-based variable delay line,which includes a fiber stretcher driven by a piezo-transducer for fast action with 1 kHz bandwidth and a temperature controlled fiber spool with a delay adjustment range of 5 ns.Compared with electronic phase compensation technique,this approach is insensitive to microwave leakages which is difficult to avoid in such a case,consequently,enables a better instability for long terms.In addition,we synthesized the back and forward transferred signals into two different frequencies to avoid effect introduced by stray optical reflections,and employ dispersion-compensation fiber to reduce the penalty due to the chromatic dispersion.

关 键 词：微波频率传递 多普勒噪声消除 光纤色散补偿 可变延迟线 频率稳定度 

分 类 号：TN929.11[电子电信—通信与信息系统]