毕业设计说明书中文摘要焦距值是光学元件的最基本参数，焦距值测量结果的精确性至关重要。本文深入研究分析了利用Ronchi光栅的测量焦距的原理和方法，根据Talbot效应与莫尔条纹技术给出了中长焦距测量的计算公式；利用两次莫尔条纹间的转角的关系对焦距公式进行了优化；对系统测量精度的影响参数进行分析讨论并利用Matlab仿真出系统测量的相对不确定度和莫尔条纹质量与系统各几何参数间的关系。通过仿真图的对比，选出在焦距值为5m—80m的测量范围内，使得系统测量精度最优的参数值，分别为：被测透镜到光栅的间距s=200mm、两块Ronchi光栅的间距=200mm、两块Ronchi光栅栅线间的夹角θ=2。5º、光栅的周期µm ；利用Matlab仿真得出此时系统可测量精度优于1。5%，搭建实验装置测量60m的焦距时相对误差为1。1%，符合仿真结果。81684

毕业论文关键词  焦距测量  Talbot效应  莫尔条纹  Matlab仿真

毕业设计说明书外文摘要

Title    Research on focal length measurement     based on Ronchi grating                   

Abstract  The focal length is the most basic parameter of the optical element, and the accuracy of the measurement  is very important。 The principle of measuring the focal length based on Talbot effect and moiré fringe technology is deeply studied and the calculation formula of focal length is given according to them。 Then the focal length formula was optimized by using the relationship between two  roll angles of  moire fringes。 Effect the measurement precision of the system parameters were discussed and the change of relative uncertainty of the measurement system and the quality of moiré fringe with geometric parameters were simulated by using MATLAB software。 Through comparison of simulation diagram,in the focal length range of 5 m to 80 m, the optimal parameter values were chosen causing the system measuring accuracy, respectively is: test lens  to the grating spacing s = 200 mm, two Ronchi gratings spacing d= 200 mm, the Angle between the two of Ronchi gratings grid line θ = 2。5 º,the period of the grantings p=20µm。the result of Matlab simulation show that the measurement accuracy of this system is better than 1。5%。 The relative error of the system when measuring the focal length of 60m is 1。1%, which is consistent with the simulation results。

Keywords  focal length measurement   Talbot effect   Moiré fringe 

Matlab simulation

目   次

1  绪论 1

1。1  研究背景 1

1。2  常规透镜焦距测量方法 1

1。3  课题研究内容 6

2  Talbot效应和莫尔条纹技术 7

2。1  Talbot效应原理 7

2。2  莫尔条纹技术原理 11

3  基于Talbot效应的焦距测量方法 15

3。1  测量原理 15

3。2  公式推导 15

3。3  公式优化 17

4  测量系统的设计与误差分析 19

4。1  系统的总体构成 19

4。2  系统参数分析 20

4。3  关键部件设计