摘要
基于频率纠缠光源及二阶量子干涉的时间同步协议中,利用Hong-Ou-Mandel(HOM)干涉实现纠缠光源至两臂的被同步钟环路时延平衡是实现时钟同步的关键,因而,时间同步的精度受限于HOM干涉环路两臂平衡的锁定精度。提出了一种锁定方法侧边锁定来实现干涉环路两臂平衡的锁定,并且与之前的顶端锁定方法进行了对比,分析给出了侧边锁定时的反馈速率比顶端锁定时提升了一倍,同时提高了干涉环路两臂平衡锁定的长期稳定性。利用该锁定方法,实验上实现了基于光纤路径的环路锁定。实验研究表明,随着光纤链路长度的增加,即当光纤长度分别为0,1和2km时,光纤干涉环路两臂平衡锁定的长期稳定度在2ks时均可以达到5fs,为长距离长时间高精度的量子时间同步奠定了良好的基础。
In the time synchronization protocol based on the quantum second-order interference of the entangled photon pairs,the balance of the propagation loops between the entangled bi-photons and the two clocks to be synchronized based on a Hong-Ou-Mandel(HOM)interferometer is the key point to realize the clock synchronization.The accuracy of the time synchronization is limited by the locking stability of the balance of the interference loop.In this paper,a new method of side locking is proposed to improve the locking stability of the propagation loop,and experimentally verified on fiber links with different lengths.According to the results,the feedback rate of this method is twice as fast as that of the previously-used top locking,and the long-term locking stability is obviously improved.Furthermore,by comparing the locking stability of the fiber loops with lengths of0km,1km and2km respectively,the dependence of the locking stability on the fiber propagation length is investigated.It can be seen that though there is such dependence,the long-term stability of the fiber loop based on side locking can still reach a fairly good result:5fs at20ks,which lays a good foundation for the long-term and high-precision quantum time synchronization.
作者
翟艺伟
权润爱
王盟盟
侯飞雁
项晓
张首刚
刘涛
董瑞芳
ZHAI Yi-wei;QUAN Run-ai;WANG Meng-meng;HOU Fei-yan;XIANG Xiao;ZHANG Shou-gang;LIU Tao;DONG Rui-fang(National Time Service Center,Chinese Academy of Sciences,Xi'an 710600,China;Key Laboratory of Time and Frequency Primary Standards,Chinese Academy of Sciences,Xi'an 710600,China;University of Chinese Academy of Sciences,Beijing 100049,China;School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 101048,China)
出处
《时间频率学报》
CSCD
2018年第4期294-299,共6页
Journal of Time and Frequency
基金
国家自然科学基金资助项目(61025023
11273024
91836301
61875205)
中国科学院科研仪器设备研制资助项目
中国科学院前沿科学重点研究资助项目(QYZDB-SSWSLH007
QYZDB-SSWJSC013)
中组部"青年拔尖人才支持计划"资助项目(组厅字[2013]33号)
国家重点研发资助项目(2017YFA0304000)
关键词
时间同步协议
二阶量子干涉
侧边锁定
长期稳定度
time synchronization protocol
second-order quantum interference
side locking
longterm stability
