一种基于3×3光纤耦合器的短距离光纤频率传递的噪声抑制方法  

Noise Suppression of Frequency Transfer on Short-distance Optical Fiber Link Based on 3×3 Fiber Coupler

作　　者：胡珍源[1,2] 岳耀笠 张颜艳[1] 高帅和[1] 杨西光 眭明 潘志兵 张首刚 李阳[1] HU Zhenyuan;YUE Yaoli;ZHANG Yanyan;GAO Shuaihe;YANG Xiguang;SUI Ming;PAN Zhibing;ZHANG Shougang;LI Yang(National Time Service Center,Chinese Academy of Sciences,Xi′an 710600,China;University of Chinese Academic of Sciences,Beijing 100049,China;The 34th Research Institute of CETC,Guilin 541004,China)

机构地区：[1]中国科学院国家授时中心,西安710600 [2]中国科学院大学,北京100049 [3]中国电子科技集团第三十四研究所,桂林541004

出　　处：《光子学报》2023年第1期88-98,共11页Acta Photonica Sinica

基　　金：中国科学院战略性先导科技专项(No.XDB35030101);国家重点研究发展计划(No.2020YFA0309800);陕西省自然科学基金(No.2020JQ434);西部之光(No.E016YR1R);陕西省人才计划项目(No.E039SB1K)。

摘　　要：提出了一种噪声抑制方法,设计了基于3×3光纤耦合器迈克尔逊干涉仪的频率传递系统,使用嵌入式系统进行控制,通过调整光纤长度,实时补偿由温度变化等环境因素引起的时延变化,并进行了实验验证。启用时延补偿后,实验用的30 m长传输光纤在环境温度变化21℃条件下长度变化量小于±1μm,对应时间延迟变化量小于10 fs,所传输的光梳重频信号的频率稳定度没有明显变化。本文工作有望为空间条件下的光钟信号向比对设备的传输路径噪声抑制提供有效的解决方法。Optical clocks have reached an instability level of 10^(-19). Remote clock comparisons require more stable frequency transfer systems. Remote time and frequency transfer are currently performed using RF link or laser link. The signal pathway between the clock and RF/laser transceiver also requires high stability. In some applications, ambient temperature change is the main noise source. However, it is difficult to control optical fiber temperature precisely under certain circumstances such as on a space station.A noise suppression method is developed and a frequency transfer system is designed using Michelson interferometer based on a 3×3 fiber coupler. A 3×3 fiber coupler rather than a 2×2 fiber coupler is chosen to build a Michelson interferometer because the direction of the fiber length change can be judged effectively when a 3×3 fiber coupler is used. An optical comb is used as a frequency source, with a wavelength of 1550 nm, an output power of 40 mW, and f_(r)(repetition frequency) at 200 MHz. A 1 310 nm CW-laser is used as a measurement scale. The two laser beams are input into the same optical fiber via a WDM.Another WDM split the two laser beams at the end of the optical fiber. The optical comb laser beam can be directly input into the target device. The measurement laser beam is reflected by a Faraday rotation mirror back to the fiber coupler. The optical fiber is the measuring arm of the Michelson interferometer.Photodiodes detect the interference fringe.An embedded system is employed in counting the interference fringe shift amount, calculating the compensation value, tuning the fiber length, and compensating the time delay variation in real time. A compensation device was built, and experiments were carried out.The experimental system is mainly composed of a compensation device, 30 m optical fiber, wavelength division multiplexers, Faraday rotation mirrors, and other auxiliary devices. The temperature of the 30 m optical fiber is controlled by an external TEC. For each test, the temperature of 3

关 键 词：光纤干涉仪 频率传递 噪声抑制 条纹计数法 波分复用 

分 类 号：TN929.11[电子电信—通信与信息系统]