基于双驱动马赫-曾德尔调制器的激光测距研究  

Dual-Drive Mach-Zehnder Modulator-Based Laser Ranging Technology

作　　者：张博峰 赵刚[1,2] 闫晓娟 马维光[1,2] Zhang Bofeng;Zhao Gang;Yan Xiaojuan;Ma Weiguang(State Key Laboratory of Quantum Optics and Quantum Optics Devices,Institute of Laser Spectroscopy,Shanxi University,Taiyuan 030006,Shanxi,China;Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,Shanxi,China)

机构地区：[1]山西大学激光光谱研究所量子光学与光量子器件国家重点实验室,山西太原030006 [2]山西大学极端光学协同创新中心,山西太原030006

出　　处：《中国激光》2023年第2期57-63,共7页Chinese Journal of Lasers

基　　金：国家重点研发计划(2017YFA0304203);国家自然科学基金(61875107,61905136,61905134,62175139)。

摘　　要：提出了一种基于双驱动马赫-曾德尔调制器(DD-MZM)的激光测距技术。通过对DD-MZM的单路进行调制可产生测距用的类双频光源,DD-MZM中两路光的时间延迟差很小,可有效抑制两路光拍频信号的强度噪声。为了进一步抑制由温度变化造成的两路光的相位差噪声,通过实时反馈控制DD-MZM的直流输入端,补偿了两路的相位差。首先基于光场传输函数建立了测距理论模型,分析了相位反馈控制的机理;然后基于理论模型搭建了测距系统,采用降频法采样信号;最后利用相位法反演出距离值。结果显示,在动态控制相位差后,系统相位差的长期漂移抑制比可达11 dB,距离测量的稳定度达到0.4μm。该方案有利于提高激光测距系统的稳定性和集成度。Objective Ranging technology has important applications in many fields.Lasers have excellent coherence and high brightness,and therefore,their employment in ranging has rapidly promoted the development of various absolute or relative distance measurement technologies.Among them,dual-frequency laser ranging technology,which combines multi-wavelength interferometry and the phase method,has been demonstrated to be a powerful ranging tool.The distance is deduced by the relative phase difference between two beat frequencies generated in the echo light and reference light,each of which is composed of two lasers with different frequencies.However,the application and generalization of the traditional dual-frequency laser ranging technology are impeded by its complexity,limited measuring range,low phase detection stability,large phase noise,and low sensitivity.Methods We propose a novel dual-frequency laser ranging technology based on a dual-drive Mach-Zehnder modulator(DD-MZM).Only the light in one of the two phase modulators inside the DD-MZM is modulated by a radio frequency and then is combined with that within the other phase modulator.Consequently,a light source analogous to a dual-frequency laser is generated in the output of the DD-MZM.The noise intensity induced by the phase difference is significantly suppressed due to the tiny difference in the phase shifts between the two light paths inside the DD-MZM.In addition,to further restrict the phase difference noise,a real-time phase shift control is implemented in one path of the DD-MZM using a feedback loop.The error signal of the feedback is generated from the direct current(DC) output of one detector monitoring the beat note relative to the phase noise.In this paper,the theoretical model for laser ranging is first presented using the electromagnetic transfer function.Subsequently,the principle of feedback control is analyzed.Based on the model,the experimental setup is established.The signal is acquired using frequency down-conversion and the distance information

关 键 词：测量 激光测距 双驱动马赫-曾德尔调制器 双频光 激光频率调制 

分 类 号：TB96[机械工程—光学工程]