摘要白光扫描干涉测试法是光学精密测试领域一个重要的技术手段,它广泛应用于微观表面形貌测试、薄膜厚度测量、光纤技术、干涉定位等领域。白光扫描干涉测试算法的种类很多,选择适当的算法可以使得测量精度提高,因此需要对算法进行研究,比较各类算法的优缺点。在白光扫描干涉测试算法中,空间频域算法具有精度高的优势,可以应用于频谱不对称分布的光源,能够有效定位零光程差位置。五步法具有计算量小和计算误差小的优点,能够减少光源的不均匀性引起的误差,在测量精度和计算效率两方面均有不错的表现。因此这两种算法均具有较好的应用背景和研究价值,是本文研究的主要内容。67206
本文首先介绍了空间频域算法以及五步法的基本原理。其次基于空间频域法的基本原理,详细叙述了其具体的算法流程。最后通过编写程序实现空间频域法的功能,利用白光干涉微观表面形貌测试系统获取被测件表面的白光干涉条纹,采用编写的程序处理实际的条纹图样,分析所得结果。结果证明:空间频域算法在测试微观表面形貌时,是能够精确地定位零光程差位置的,可以得到准确的表面高度信息。
毕业论文关键字:光学精密测试 白光干涉 空间频域算法 五步法
毕业设计说明书(论文)外文摘要
Title The Algorithms of White-light Scanning Interferometry
Abstract
Scanning White-light Interferometry(SWLI) is an important technical means in the field of optical precision measurements, so it is widely used in microscopic surface morphology measurement, film thickness measurement, optical fiber technology, interference location and other aspects. The algorithms of Scanning White-light Interferometry(SWLI) are various, and it can make the measurement accuracy better to select the appropriate algorithm. Therefore the algorithms should be studied and compared between each other, which shows their advantages and disadvantages. In the algorithms of Scanning White-light Interferometry(SWLI), Spatial Frequency Domain Analysis has the advantage of high precision and can be applied to the light source with asymmetric spectrum distribution, which can effectively locate the position where Optical Path Difference(OPD) is zero. With less computation and calculation error, Five-step method can decrease the errors caused by the inhomogeneous light source and it has superior measurement accuracy and computational efficiency. Therefore, these two algorithms have better application background and research value, which are the main content of this paper.
Firstly, this paper describes the basic principles of the spatial frequency domain analysis and five-step method. Secondly, based on the basic principle of spatial frequency domain algorithm, its specific algorithm process is described in detail. Finally, writing program to achieve the function of spatial frequency domain method, with the use of the system of white light interference microscopic surface morphology to obtain the white light interference fringes, the actual fringe pattern is handled by using the above program and then make the analysis of results. Results show that: when the spatial frequency domain algorithm is used to measure microscopic surface topography, it has the ability to accurately locate the position of zero optical path difference position and then it can obtain the accurate surface height information.
Keywords Optical Precision Measurements; White-light interferometry; Frequency Domain Analysis (FDA); Five-step Phase-shifting Algorithm