基于相关度的白光干涉信号解调算法  

White Light Interference Signal Demodulation Algorithm Based on Correlation

作　　者：张振清 董丽娟[2] 孙勇[3] ZHANG Zhen-qing;DONG Li-juan;SUN Yong(Department of Criminal Science and Technology,Railway Police College,Zhengzhou 450053,China;Shanxi Provincial Key Laboratory of Microstructure Electromagnetic Functional Materials,Shanxi Datong University,Datong 037009,China;MOE Key Laboratory of Advanced Micro-Structured Materials,School of Physics Science and Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]铁道警察学院刑事科学技术系,河南郑州450053 [2]山西大同大学微结构电磁功能材料山西省重点实验室,山西大同037009 [3]同济大学物理科学与工程学院,先进微结构材料教育部重点实验室,上海200092

出　　处：《光谱学与光谱分析》2023年第6期1941-1946,共6页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(11974261);山西省科技创新团队项目(201805D131006);山西省重点研发计划项目(201903D121026);中央引导地方科技发展资金项目(YDZJSX2021B011)资助。

摘　　要：超精密的微纳器件是制造领域的核心器件,随着超精密加工技术的迅猛发展,对相应的微纳检测技术要求越来越高。微纳检测技术是保证超精密加工技术精确稳定的重要手段,是超精密加工技术进一步发展的前提。现有的微纳器件表面轮廓检测方法按是否使用光学原理可以分为光学类和非光学类,非光学类检测通常为点扫描、接触检测的方式,检测效率低,容易破坏待测器件的表面形貌。光学类的检测方式多为面扫描,非接触式测量,不会划伤待测器件,检测效率高。在光学检测中,白光干涉技术由于其相干长度短的特点,可实现微纳器件三维形貌的高精度测量,受到国内外研究人员的广泛关注。在白光干涉检测技术中,信号解调算法对整个检测系统至关重要,传统的白光干涉信号解调算法只采用了干涉信号的部分信息,解调精度较低,而高精度的相移解调算法又依赖于粗定位的精度,无法直接实现高精度的三维形貌恢复。为了解决以上问题,提出以相关度为基础的信号解调算法,该算法通过三级滑动窗口计算相关度,利用了白光干涉信号的全部信息,无需粗定位,就可直接确定待测物体的表面三维形貌信息。为验证该算法的性能,对其进行了模拟仿真和实验验证。模拟仿真结果表明该方法具有可行性,可准确恢复仿真待测三维结构形貌,采用三级滑动窗的设置可有效提高运算效率。同时,搭建了白光干涉垂直扫描实验系统,并对光栅结构和微透镜结构进行了测量,将实验结果与传统的重心法和相移法进行了比较。实验结果表明该方法能准确恢复出不同物体的三维形貌,精度及鲁棒性均优于改进的重心法,接近相移法,光栅高度的恢复结果表明该方法与相移法的误差小于0.5 nm。仿真和实验结果表明,所提出的基于相关度的白光干涉信号解调方法是可行的,无需粗定位便可�Ultra precision micro nano devices are the core devices in the manufacturing field.With the rapid development of ultra-precision machining technology,the corresponding micro nano detection technology is required to be higher and higher.Micro nano measurement technology is an important means to ensure the accuracy and stability of ultra-precision machining technology and is the premise for further development.The surface profile detection methods for micro/nanodevices can be divided into optical and non-optical types according to whether optical principles are used.Non-optical detection usually adopts point scanning and contact detection,which is inefficient and easy to damages the surface morphology of the device to be tested.Optical detection methods are mostly surface scanning,and non-contact measurement,which will not scratch the device to be tested,and the detection efficiency is high.In optical detection,white light interferometry has been widely concerned by researchers at home and abroad because of its short coherence length,which can achieve high-precision measurement of three-dimensional morphology of micro-nano devices.In white light interference detection technology,the signal demodulation algorithm is very important to the entire detection system.Traditional white light interference signal demodulation algorithm only uses part of the information of the interference signal,which has low demodulation accuracy.However,high-precision phase shift demodulation algorithm depends on the accuracy of rough positioning,which cannot directly achieve the high-precision three-dimensional shape recovery.In order to solve the above problems,this paper proposes a signal demodulation algorithm based on the correlation.This algorithm calculates the correlation through a three-level sliding window and uses all the white light interference signal information.Without rough positioning,it can directly determine the three-dimensional surface topography information of the object to be measured.In order to verify the performan

关 键 词：白光干涉 相关算法 三维形貌 

分 类 号：TN911.74[电子电信—通信与信息系统]