Coherent Optical Frequency Transfer via a 490 km Noisy Fiber Link  

作　　者：Xiang Zhang Xue Deng Qi Zang Dongdong Jiao Jing Gao Dan Wang Qian Zhou Jie Liu Guanjun Xu Ruifang Dong Tao Liu Shougang Zhang 张翔;邓雪;臧琦;焦东东;高静;王丹;周茜;刘杰;许冠军;董瑞芳;刘涛;张首刚(National Time Service Center,Chinese Academy of Sciences,Xi’an 710600,China;University of Chinese Academy of Sciences,Beijing 100039,China;Key Laboratory of Time and Frequency Standards,Chinese Academy of Sciences,Xi’an 710600,China)

机构地区：[1]National Time Service Center,Chinese Academy of Sciences,Xi’an 710600,China [2]University of Chinese Academy of Sciences,Beijing 100039,China [3]Key Laboratory of Time and Frequency Standards,Chinese Academy of Sciences,Xi’an 710600,China

出　　处：《Chinese Physics Letters》2022年第4期7-11,共5页中国物理快报（英文版）

基　　金：supported by the National Key Research and Development Program of China(Grant No.2016YFF0200200);the National Natural Science Foundation of China(Grant Nos.91636101,12103059,91836301,and 11803041);the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.1188000XGJ);the West Light Foundation of the Chinese Academy of Sciences(Grant No.XAB2016B47);the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB21000000)。

摘　　要：We demonstrate the coherent transfer of an ultrastable optical frequency reference over a 490 km noisy field fiber link.The fiber-induced phase noise power spectrum density per-unit-length at 1 Hz offset frequency can reach up to 510 rad^(2)·Hz^(-1)·km^(-1),which is much higher than the fiber noise observed in previous reports.This extreme level of phase noise is mainly due to the fiber link laying underground along the highway.Appropriate phaselocked loop parameters are chosen to complete the active compensation of fiber noise by measuring the intensity fluctuation of additional phase noise and designing a homemade digital frequency division phase discriminator with a large phase detection range of 2^(12)πrad.Finally,a noise suppression intensity of approximately 40 d B at1 Hz is obtained,with fractional frequency instability of 1.1×10^(-14 )at 1 s averaging time,and 3.7×10^(-19) at10000 s.The transfer system will be used for remote atomic clock comparisons and optical frequency distribution over a long-distance communication network established in China.

关 键 词：FIBER noise UNDERGROUND 

分 类 号：TN929.11[电子电信—通信与信息系统]