【作者】 邹瑾；

【导师】 葛宝臻；

【作者基本信息】 天津大学 ， 光学工程， 2005， 硕士

【摘要】 随着微加工技术的快速发展,微结构表面形貌的获取越来越受到人们的关注。数字全息技术将光学全息与数字技术结合起来,利用CCD器件直接记录数字全息图,通过在计算机中的数字再现可以同时获得物体再现的振幅像和相位像。高分辨率的、快速的、非接触的、无损的、测量便捷的数字全息技术已发展为一种新的微观领域的测试工具,为诸多领域广泛关注。本文主要围绕数字全息技术在物体表面形貌测量方面的应用展开研究,系统的分析了离轴菲涅尔数字全息系统和基于4f系统的离轴菲涅尔数字全息系统用于形貌测量的基本理论,并进行了实验研究,主要内容如下:1.系统的分析了数字全息用于表面形貌测试的基本理论;2.针对数字全息再现中的再现光的载频系数和再现距离的调整方法进行了理论分析。提出用寻找物体空间频谱中心的方法确定再现光的载频系数,保证数字全息的准确再现,对该方法进行了模拟分析及实验验证。并提出利用“Gray”(灰度值)算法、“Entropy”(熵)的算法和“Tenengrad”(梯度)的算法确定再现距离,对三种算法进行了理论模拟。3.提出应用4f系统的成像特性消除二次相位因子对物体相位信息的干扰,并设计了基于4f系统的离轴菲涅尔数字全息系统。4.在理论分析的基础上,分别对离轴菲涅尔数字全息和基于4f系统的离轴菲涅尔数字全息进行了实验研究。更多还原

【Abstract】 With the fast development of the micro-machining, the technology ofmicrostructure topography information obtained becomes an increasing concernedsubject. Digital holography is a technology that combines the digital technology andtraditional optical holography, the hologram generated by object is recorded directlyby CCD and stored digitally by computer, and then reconstructed numerically. Andintensity as well as phase information of a holographically stored wavefront can beachieved directly in the numerical reconstruction process. Digital holography is ahigh-resolution, quick, non-contact and non-invasive, and easy measurementtechnique and now has been developed into the prospect of a powerful new tool formicrodomain measurement and becomes an increasing and wide attention in variousfields.This paper centering about the application of object surfect topographymeasurement with digital holography is studied, and the basic theory of off-axisFresnel digital holographic system and the off-axis Fresnel digital holographic systembased on 4f for topography measurement have been analysized and experimentalresearch have been also done. The main contents of this paper are as follows:1. The basic theory of digital holography for surface topography measurementhas been analysized.2. The method adjusting the reconstructing light carrier frequency coefficientand the reconstructed distance in digital holography is analyzed theoretically.The method determined the reconstructing light carrier frequency coefficientby looking for the space-frequency center of object is presented, and thegood reconstructed images of digital holography are been obtained. Thesimulation analysis and the experimental validation have been completed.The method that decides the reconstructed distance in numericalreconstruction with the algorithms of “Grey level local variance”, “Entropy”and “Tenengrad” has been also proposed, and theoretical simulation hasbeen done.3. The method that eliminates the disturb from a parabolic phase factor toobject’s phase information by using the image character of 4f system hasbeen presented and a optics system of off-axis fresnel digital holographybased on 4f system has been designed.4. The experimental research of off-axis fresnel digital holography and off-axisfresnel digital holography based on 4f system has been done based on thetheories.更多还原