收发望远镜参数对光纤激光测振仪测量分辨力的影响  

Influence of transmitting and receiving telescope parameters on measurement resolution of fiber laser doppler vibrometer

作　　者：沈杨翊 戴玉 孔新新 赵思泽鹏 张文喜 SHEN Yangyi;DAI Yu;KONG Xinxin;ZHAO Sizepeng;ZHANG Wenxi(Aerospace Information Research Institute,Chinese Academy of Science,Beijing 100094,China;School of Optoeletronics,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院空天信息创新研究院,北京100094 [2]中国科学院大学光电学院,北京100049

出　　处：《物理学报》2025年第1期176-183,共8页Acta Physica Sinica

基　　金：国家重点研究发展计划(批准号:2022YFF0706300)资助的课题.

摘　　要：激光外差干涉测量是非接触振动探测的重要手段,随着探测目标距离拓展,人们对激光测振仪能量利用率和测量分辨力提出了更高的要求.基于菲涅耳衍射积分、光纤耦合等相关理论,建立了收发一体式光纤激光测振仪光场传递模型,并基于散粒噪声受限假设,提出粗糙目标回光情况仪器噪声基底评价方法.结果表明,收发望远镜焦距和口径共同决定系统能量利用率分布情况,并进一步影响仪器测量分辨力.针对激光波长为1550 nm,光纤模场半径为5μm,对准距离为1 km的典型应用场景进行数值仿真实验,收发透镜最优F数为3.3,验证了模型的正确性,仿真结果可作为光纤激光测振仪、激光测风雷达等收发镜头设计的依据.In a laser Doppler vibrometer(LDV),the laser Doppler effect is used to real-time acquire target displacement,velocity,and acceleration.Fiber optic laser vibrometers have received widespread attention in recent years due to their strong environmental adaptability and high integration advantages.With the expansion of detection target distance,higher requirements have been put forward for the measurement resolution of laser vibrometers.The LDV system typically employs a transceiver integrated telescope structure for laser emission and target return light reception.The aperture and focal length of the transceiver telescope determine its basic structure,directly affecting the emission and reception efficiency of laser energy.Additionally,the speckle effect generated by the scattering of rough targets affects the coupling of light energy entering the fiber optic for interference,thereby influencing the LDV measurement resolution.Based on relevant theories such as Gaussian beam waist transmission,rough target generation,Fresnel diffraction integration,and fiber optic coupling,a transceiver integrated fiber optic laser vibrometer optical field transmission model is established.Numerical simulation and analysis of the emission transmission process of ideal Gaussian laser and the coupling process of surface target echo reception are conducted.Based on the assumption of laser vibrometer speckle noise limitation,an evaluation scheme for the instrument’s noise baseline under rough target return light conditions is proposed.Numerical simulation experiments are conducted for a typical fiber LDV application scenario with an alignment distance of 1 km,a single-mode fiber mode field radius of 5μm,and a laser wavelength of 1550 nm.The results indicate that the focal length and aperture of the transceiver telescope determine the distribution of system energy utilization and further affect the instrument’s noise baseline.Simulation results show that when the F-number of the transceiver lens reaches 3.3,LDV achieves the highest s

关 键 词：激光多普勒效应 光场传递 散斑 光纤耦合 

分 类 号：TH74[机械工程—光学工程] TN249[机械工程—仪器科学与技术]