基于Fourier频谱分析的白光干涉信号解算方法  

White Light Interference Signal Processing Method Based on Fourier Frequency Spectrum Analysis

作　　者：杜海龙 段照斌 孙晓东[2] Du Hailong;Duan Zhaobin;Sun Xiaodong(Engineering Techniques Training Center National Experimental Teaching Demonstrating Center,Civil Aviation University of China,Tianjin 300300,China;School of Electrical and Electronic Engineering,Tiangong University,Tianjin 300387,China)

机构地区：[1]中国民航大学工程技术训练中心国家级实验教学示范中心,天津300300 [2]天津工业大学电气与电子工程学院,天津300387

出　　处：《激光与光电子学进展》2021年第9期211-216,共6页Laser & Optoelectronics Progress

基　　金：国家自然科学基金青年项目(61605144)。

摘　　要：采样噪声对白光干涉信号Fourier频谱的各个频率均有影响.选用合适的滤波方法进行滤波将有助于提高白光干涉信号信噪比并获得更加准确的解算结果。构建了特定能量比例条件下的能量最集中约束条件,并建立了选取带通滤波器的代价方程。实验给出了白光LED照明条件下代价方程的部分计算过程和结果,代价方程取得最小值时表面粗糙度测量标准差仅为0.02nm。最后在所选参数条件下对银膜反射镜和台阶结构进行了测量,结果表明所提方法具有较好的测量重复性和分辨率。Sampling noise affects each frequency of white light interference signal Fourier frequency spectrum.Selecting an appropriate filter method will help improve the signal-to-noise ratio of a white light interference signal and obtain highly accurate solution results. In this study,an energy concentration constraint under a certain energy ratio is constructed,and a cost function for selecting the bandpass filter is established. The part calculation process and results of the cost equation under white light LED illumination are given in the experiment. When the cost function reaches its minimum value,the standard deviation of surface roughness is only 0. 02 nm. Finally,a silver mirror and a step structure are measured under the selected parameters. The results show that the proposed method has good performances with respect to repeatability and resolution.

关 键 词：傅里叶光学 白光干涉信号 FOURIER变换 包络线 代价函数 

分 类 号：TH741[机械工程—光学工程]