多普勒激光雷达多模光纤Mach-Zehnder干涉仪鉴频系统准单模设计及实现  

Quasi Single Mode Design and Implementation of Doppler Lidar Frequency Discrimination System Based on Multimode Fiber Mach-Zehnder Interferometer

作　　者：汪丽[1] 陈阳 索建平 潘睿 王东 高飞[1] 华灯鑫[1] Wang Li;Chen Yang;Suo Jianping;Pan Rui;Wang Dong;Gao Fei;Hua Dengxin(Faculty of Mechanical and Precision Instrument Engineering,Xi′an University of Technology,Xi′an,Shaanxi 710048,China)

机构地区：[1]西安理工大学机械与精密仪器工程学院,陕西西安710048

出　　处：《光学学报》2020年第17期53-63,共11页Acta Optica Sinica

基　　金：国家自然科学基金(61775179,41627807)。

摘　　要：多普勒激光雷达在大气风场探测方面已经得到了广泛应用。光纤Mach-Zehnder干涉仪(MZI)作为多普勒激光雷达的新型鉴频系统,具有体积小、轻便、稳定性高的优点。鉴于一般常用的单模光纤MZI与望远镜接收系统的多模光纤直接耦合时能量耦合损耗严重、耦合效率低的缺点,提出采用多模光纤MZI作为鉴频系统,以提高耦合效率,实现能量及探测高度的增加。针对多模光纤MZI可能产生的干涉质量下降问题,利用调整入射角及扰模方式实现多模光纤准单模输出,理论计算结果表明实验所用多模光纤准单模输出对应的入射角度为0.8°,扰模直径为2.2 cm,并进行了实验验证。通过对多普勒激光雷达系统的风场探测信噪比的仿真和对比分析可得,多模光纤MZI作为鉴频器将有效提升系统探测性能。The Doppler lidar has been widely used in the detection of atmospheric wind field.An optical fiber Mach-Zehnder interferometer(MZI)used as a new frequency discrimination system for the Doppler lidar,has the advantages of small size,light weight,and high stability.To address the problems of serious energy coupling loss and low coupling efficiency when the commonly used single-mode fiber MZI is directly coupled with the multimode fiber of the telescope receiving system,the multimode fiber MZI is proposed as a frequency discrimination system to improve the coupling efficiency and increase the energy and detection height.In order to solve the problem of interference quality degradation caused by the multimode fiber MZI,the quasi single mode output of the multimode fiber is realized by adjusting the incident angle and disturbing mode.Theoretical calculation results show that the incident angle of the quasi single mode output of the multimode fiber used in the experiment is 0.8°and the diameter of the disturbed mode is 2.2 cm,which are experimentally verified.Through the simulation and comparative analysis of the signal-to-noise ratio of Doppler lidar wind measurement,we find that the multimode fiber MZI used as a frequency discriminator will effectively improve the system detection performance.

关 键 词：光通信 激光雷达 多模光纤Mach-Zehnder干涉仪 准单模 扰模直径 

分 类 号：TN253[电子电信—物理电子学]