摘要
为了解决白光干涉相位求解问题,实现微观形貌的高度测量,提出了基于主成分分析(Principal Component Analysis,PCA)的白光干涉(White Light Interferometry,WLI)微观形貌测量算法。通过搭建的白光干涉显微系统采集多幅干涉图,将其重构成向量形式。在一组干涉图中,用时间平均值来估计背景照明,消除背景光成分。然后,通过矩阵运算得到代表原始数据的特征值及其特征向量。最后,通过反正切函数计算物体的包裹相位分布。实验结果表明,本文所提方法对于标定高度为956.05 nm的台阶测量结果为953.66 nm,且可以获得与迭代算法近似的解,而本文所提方法与迭代算法相比,处理速度提高了2个数量级。利用本文方法分析了表面粗糙度为0.025μm样块的干涉条纹。结果显示:计算得到的表面粗糙度均值为24.83 nm,标准差为0.3831 nm。本文提出的方法解决了单色光干涉测量中的不足,还具有计算简单、速度快及精度高等优势。
A white light interferometry micro measurement algorithm based on principal component analysis is proposed to solve the problem of the phase solution in white light interferometry and realize the height measurement of micro morphology.The white light microscopic interference system is used to collect multiple interferograms and reconstruct them into vector form.From a set of interferograms,the background illumination can be estimated by a temporal average,eliminating background light components.Then,the eigenvalues and eigenvectors representing the original data are obtained by a matrix operation.Finally,the phase distribution is calculated by the arctangent function.Experimental results indicate that the measurement result of a standard step height of 956.05 nm by the proposed method is about 953.66 nm and the solution is approximately consistent with the iterative algorithm.In comparison to the iterative algorithm,the processing speed of the proposed method is 2 orders of magnitude faster.The interference fringes with surface roughness of 0.025μm is analyzed,the mean of the surface roughness calculated by the proposed method is 24.83 nm,and the sample’s standard deviation is 0.3831 nm.The proposed method improves the deficiency of monochromatic interferometry and has the advantages of high speed,low computational requirements and high accuracy.
作者
陈浩博
张力伟
孙文卿
陈宝华
曹召良
吴泉英
CHEN Hao-bo;ZHANG Li-wei;SUN Wen-qing;CHEN Bao-hua;CAO Zhao-liang;WU Quan-ying(School of Physical Science and Technology,Suzhou University of Science and Technology,Suzhou 215009,China;Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application,Suzhou 215009,China)
出处
《中国光学（中英文）》
EI
CAS
CSCD
北大核心
2023年第3期637-644,共8页
Chinese Optics
基金
国家自然科学基金(No.61875145,No.11804243)
“十四五”江苏省重点学科资助(No.2021135)
苏州市科技计划前瞻性应用研究项目(No.SYG202013)。
关键词
光学测量
白光干涉
主成分分析
微观形貌测量
optical testing
white light interferometry
principal component analysis
micro topography measurement
