光反馈自混合干涉位移实时跟踪测量算法的研究

发布时间：2018-03-07 10:02

本文选题：位移测量　切入点：光反馈自混合干涉　出处：《郑州大学》2017年硕士论文　论文类型：学位论文

【摘要】：光反馈自混合干涉(Optical Feedback Self-Mixing Interference,简称OFSMI)效应是指激光器输出光经外部反射体反射或散射后,其中一部分光又反馈回激光器谐振腔,反馈光与腔内光相干涉,从而调制激光器输出光功率的现象。由于OFSMI信号中含有外部反射体运动信息,所以OFSMI系统可以用于外部反射体位移测量。OFSMI位移测量系统和传统双光束干涉测量系统有相同的测量灵敏度,但具有硬件结构更简单、紧凑、易准直等优点,所以OFSMI位移测量的研究有一定的理论研究意义及实用价值。本文主要研究OFSMI位移实时跟踪测量算法,该算法具有以下特点:适用范围广(弱光和适度光反馈机制通用);算法实时性好;可对任意位移波形进行重构;测量精度高。测量算法主要包括两部分:整数条纹检测及对应位移测量;小数条纹位移测量。具体研究内容可归纳为如下三个方面:1、提出两种整数条纹检测算法:(1)由小波变换奇异点检测理论,研究OFSMI信号的奇异性,设计小波变换整数条纹检测算法;(2)由希尔伯特变换和解析信号理论,研究OFSMI信号希尔伯特变换得到的瞬时相位的特点,设计希尔伯特变换整数条纹检测算法。对两种整数条纹检测算法进行仿真,由仿真结果对比两种算法的抗噪声性能。2、小数条纹位移测量包括三部分:(1)由干涉条纹倾斜程度和光反馈机制的关系,设计光反馈机制判断算法;(2)由适度OFSMI信号为锯齿波和滞回现象特点,设计适度OFSMI小数条纹位移测量算法;(3)由弱OFSMI信号为类正弦波特点,设计弱OFSMI小数条纹位移测量算法。3、由希尔伯特变换整数条纹检测和小数条纹位移测量组成OFSMI位移实时跟踪测量算法,仿真和实验验证该位移测量算法对位移重构的有效性。实验结果表明本文算法测量振幅的绝对误差约为23.2nm,相对误差约为1.81%。和其他两种位移测量算法相比,本文位移测量算法测量精度高,且适用范围广。
[Abstract]:Optical Feedback Self-Mixing interference (OFM) effect means that the output light is reflected or scattered by an external reflector, and some of the light is fed back to the resonator of the laser, and the feedback light interferes with the intracavity light. Thus modulating the laser output optical power phenomenon. Because the OFSMI signal contains the external reflector motion information, Therefore, OFSMI system can be used to measure displacement of external reflector. OFSMI displacement measurement system has the same measuring sensitivity as traditional dual beam interferometry system, but it has the advantages of simple hardware structure, compact structure, easy collimation and so on. Therefore, the research of OFSMI displacement measurement has some theoretical significance and practical value. The algorithm has the following characteristics: wide range of application (weak light and moderate optical feedback mechanism), good real-time performance, reconstruction of arbitrary displacement waveforms; The measurement algorithm consists of two parts: integer fringe detection and displacement measurement; The specific research contents can be summarized as follows: 1. Two integer fringe detection algorithms: 1) based on wavelet transform singular point detection theory, the singularity of OFSMI signal is studied. An integer fringe detection algorithm based on wavelet transform is designed. Based on Hilbert transform and analytic signal theory, the characteristics of instantaneous phase obtained by Hilbert transform of OFSMI signal are studied. An integer fringe detection algorithm based on Hilbert transform is designed. Two integer fringes detection algorithms are simulated. The anti-noise performance of the two algorithms is compared with the simulation results. The fractional fringe displacement measurement includes three parts: 1) the relationship between the inclination of the interference fringes and the optical feedback mechanism. The algorithm for judging optical feedback mechanism is designed, which is characterized by moderate OFSMI signal as sawtooth wave and hysteretic phenomenon, and moderate OFSMI fractional fringe displacement measurement algorithm, which is characterized by weak OFSMI signal as sinusoidal wave. A displacement measurement algorithm of weak OFSMI fractional fringe is designed. The algorithm is composed of Hilbert transform integer fringe detection and fractional fringe displacement measurement. Simulation and experiment verify the effectiveness of the proposed displacement measurement algorithm for displacement reconstruction. The experimental results show that the absolute error of the proposed method is about 23.2nm, and the relative error is about 1.81.Compared with the other two displacement measurement algorithms. The displacement measurement algorithm in this paper has high accuracy and wide range of application.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O436.1

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