【作者】 刘京；

【导师】 张红霞； 陈家田；

【作者基本信息】 天津大学 ， 光学工程（专业学位）， 2016， 硕士

【摘要】 光学成像系统是一种重要的光学信息传递和处理系统,在很多领域有着广泛的应用。传统的光学成像系统是物面、镜头主面和像面互相平行的光学系统,但在一些成像系统中物面与镜头主面和像面是不平行的,所以倾斜成像系统的研究很有意义。倾斜成像系统广泛应用于粒子场测量,干涉粒子成像(IPI)系统是其中主要的应用。IPI系统的采样体积是研究粒子数浓度的基础,聚焦IPI系统的采样体积与成像系统的景深有关,而离焦IPI系统的采样体积与成像系统的景深无关。本论文研究聚焦和离焦IPI系统采样体积的计算公式和测量方法,搭建聚焦和离焦IPI实验系统,使用标准网格标定板和标准球形粒子分别对聚焦和离焦IPI系统的采样体积进行测量。本论文的工作对于确定倾斜成像系统的采样体积具有重要指导意义。本论文的主要工作:1.基于几何光学理论分析了IPI测量技术的基本原理,研究搭建IPI实验系统的几个关键问题:系统最佳散射角的选择,样品池不同摆放方式的影响、成像系统放大倍率的校正以及离焦IPI实验系统具体参数的计算。2.研究仅物面倾斜和物像面双倾斜这两种聚焦IPI系统的采样体积,推导采样体积的计算公式,分析采样体积与物面倾斜角、成像镜头焦距和光圈数、系统中心放大倍率的关系。比较两种成像方式发现,物像面双倾斜聚焦IPI系统的采样体积大于仅物面倾斜聚焦IPI系统的采样体积。3.搭建两种物面倾斜聚焦IPI实验系统,采集网格标定板图像,处理图像提取目标横线平均线宽,判断清晰成像范围,得到了聚焦IPI系统的采样体积。4.提出一种离焦IPI系统采样体积的确定方法,根据CCD靶面上每一个位置x处所形成的干涉条纹圆尺寸的范围12pixpixApixA(37)￡(37)￡(37)来确定采样区域。分析离焦条纹圆尺寸与后向离焦距及其在CCD靶面上位置的关系,推导了离焦IPI系统采样体积的计算公式。5.搭建离焦IPI实验系统,采集标准球形粒子的离焦干涉条纹图,对全视场的干涉条纹圆尺寸范围进行了修正,获得了离焦IPI系统的采样体积。更多还原

【Abstract】 Optical imaging system is an important optical information transmission and processing systems,which has important applications in many fields.A conventional imaging system satisfies the condition that the object plane,lens plane,and image plane are parallel to each other.However,in some imaging systems the object plane is not parallel to the lens plane and image plane;thus,the research of tilted imaging system is of great significance.The tilted imaging system is widely used in the measurement of particle field,and Interferometric particle imaging(IPI)system is an important application.The sampling volume of an IPI system is the basis to study the particle number concentration.The sampling volume of an in-focus IPI system is correlated to the depth of field,while the sampling volume of an out-of-focus IPI system has nothing to do with the depth of field.This paper studies the sampling volume of in-focus and out-of-focus IPI systems.The formula for the sampling volume has been derived,and the measurement method has been proposed.The experimental setup of in-focus and out-of-focus IPI systems have been established,the standard grid calibration plate and the standard spherical particles are used respectively to calculate the sampling volume of the in-focus and out-of-focus IPI systems.This work is of great significance to determine the sampling volume in tilted imaging systems.Main work of this paper:1.Based on geometrical optics,the basic theory of the IPI technique has been analyzed,and several key problems to develop IPI experiment system have been discussed.The choice of the best scattering angle in an IPI system has been studied,the influence of the sampling pool with different ways to put has been discussed,the calibration of magnification in an IPI system has been proposed,and the calculation of parameters in an out-of-focus IPI system has been studied.2.The sampling volume in in-focus IPI systems which are only the object plane is inclined to optical axis(Type-I)or both the object plane and image plane are inclined to the optical axis(Type-II)have been studied,the formula for the sampling volume has been derived,and the effects of the tilted angle,central magnification,focal length,and F-number on the sampling volume have been analyzed.Comparing to the two imaging methods,the sampling volume of the Type-II system is larger than that of the Type-I system.3.The experimental setup of two types of in-focus IPI systems has been established,grid calibration plate images have been acquired,the average line width of objective horizontal has been obtained by image processing,the clear imaging range has been determined,and then the sampling volume of in-focus IPI system has been calculated.4.A method to determine the sampling volume in the out-of-focus IPI systems has been proposed.The sampling region is determined by the range of the interferometric fringe circle size at each position of the CCD target surface,that is12pixpixApixA(37)￡(37)￡(37).The relationship between the interferometric fringe circle size and its position on the CCD target surface or back defocus distance has been analyzed.The formula of the sampling volume in the out-of-focus IPI system has been derived.5.The experimental setup of the out-of-focus IPI system has been established.The interferometric fringe circles of the standard spherical particles have been acquired,the range of interferometric fringe circle size within the whole view has been calibrated,and then the sampling volume of out-of-focus IPI system has been obtained.更多还原