三维显微测振中离轴光路机械形变对耦合效率的影响  

Influence of Mechanical Deformation of Off-Axis Optical Path on Coupling Efficiency in 3D Micro-Vibration Measurement

作　　者：董辉 王大勇[2] 孔新新[3] 王云新[2] Dong Hui;Wang Dayong;Kong Xinxin;Wang Yunxin(Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100124,China;Faculty of Science,Beijing University of Technology,Beijing 100124,China;Key Laboratory of Computational Optical Imaging Technology,Chinese Academy of Sciences,Beijing 100094,China)

机构地区：[1]北京工业大学材料与制造学部,北京100124 [2]北京工业大学理学部,北京100124 [3]中国科学院计算光学成像技术重点实验室,北京100094

出　　处：《光学学报》2023年第10期115-123,共9页Acta Optica Sinica

基　　金：国家自然科学基金(62075001,62275008)。

摘　　要：三维显微测振仪可用于测量微结构的三维振动,其两条离轴光路用于接收包含面内振动信息的信号光,系统的机械形变会直接影响光纤的耦合效率,从而影响系统的测振精度。结合衍射传播理论和光纤耦合原理,建立了离轴光路的信号光传输耦合模型,针对信号光平面与光纤平面存在倾角的问题,利用频域坐标旋转变换法将倾斜的物面信号光场投影到平行的参考平面上,再基于菲涅耳衍射传播计算得到光纤平面的光场分布,进而结合光纤的模场分布可计算得到光纤耦合效率。研究了耦合透镜、光纤等元件的机械形变对光纤耦合效率的影响,阐明了光纤耦合效率和各个机械变形量的关系,为三维激光多普勒显微测振系统的设计和装调工作提供了理论指导。Objective Three-dimensional(3D)laser Doppler micro-vibration measurement technology is widely applied in the research on dynamic characteristics of microstructures.Its two off-axis optical paths are employed to receive signal light containing in-plane vibration information.The optical fiber coupling efficiency in optical paths will directly affect the vibration measurement accuracy of the system.At present,the factors affecting the coupling efficiency of optical fiber mainly include optical system aberration,atmospheric turbulence,amplitude distribution type of signal light and local light,and optical system parameters.The effect of gravity,temperature,or mechanical deformation of optical elements during installation on the coupling efficiency is not considered.In addition,most of the current research focuses on onedimensional laser Doppler detection system,and there is a lack of research on 3D laser Doppler micro-vibration measurement system,especially the off-axis optical path.To this end,based on the diffraction propagation theory and the fiber coupling principle,the optical transmission and coupling model of the off-axis signal receiving optical path in the 3D micro-vibration measurement system is built in this paper.The mechanical deformation of typical optical components in the system is analyzed,and the influence of these mechanical deformations on the fiber coupling efficiency is studied.In addition,the maximum tolerances of different mechanical deformations are given.The research is of guiding significance for the design and installation of 3D laser Doppler micro-vibration measurement system.Methods The detection optical path of the 3D micro-vibration measurement system includes the main axis optical path and off-axis optical path.The main axis optical path is overlapped with the z axis.Its function is to incident the laser onto the object to be measured and receive the reflected signal light containing the vibration component information of the object in the z direction.The two off-axis optical paths ar

关 键 词：测量 干涉测量 三维显微测振 机械形变 光纤耦合 衍射传播理论 

分 类 号：O436[机械工程—光学工程]