基于多元散射校正的光谱共焦位移测量方法分析与研究  

Analysis and research of spectral confocal displacement measurement method based on multiple scattering correction

作　　者：李春艳 王泞淋 刘继红 武少杰 付雯雯 任凯利 LI Chunyan;WANG Ninglin;LIU Jihong;WU Shaojie;FU Wenwen;REN Kaili(School of Electronic Engineering,Xi'an University of Posts&Telecommunications,Xi'an 710121,China)

机构地区：[1]西安邮电大学电子工程学院,陕西西安710121

出　　处：《红外与激光工程》2025年第1期221-230,共10页Infrared and Laser Engineering

基　　金：国家自然科学基金项目(62276210);陕西省自然科学基金项目(2022JM-387);陕西省重点研发计划项目(2020GY-127)。

摘　　要：为提高光谱共焦位移测量系统精度,对样品表面散射特性的影响进行了研究。首先,介绍了光谱共焦位移测量系统的原理,基于标量散射理论,推导了表面散射特性影响下的光谱共焦轴向响应,建立了散射对位移测量影响的关系模型。然后,对散射引起的峰值波长曲线偏移导致的位移测量误差进行了理论研究和仿真分析;结果表明:在样品表面粗糙度较大时,会产生较大的散射效应,导致测量精度明显下降;同时,在进行光谱共焦位移测量时受各波长入射特性的影响。为校正散射的影响,提出采用多元散射校正方法结合广义回归神经网络(General Regression Neural Network, GRNN)对光谱数据进行处理,建立了散射校正算法模型。最后,搭建实验平台,选取样品进行了位移测量实验;实验结果表明,系统的测量性能随粗糙度的增大而降低,对于粗糙度为20 nm的样品散射误差校正后测量结果的最大位移测量误差从12.6μm降为1.9μm,平均位移测量误差从8.1μm降为0.86μm,提高了位移测量精度,验证了理论分析的正确性以及提出的散射校正方法的有效性。文中研究结果对提高光谱共焦位移测量系统的精度具有一定的参考意义。In order to improve the accuracy of spectral confocal displacement measurement system,the influence of surface scattering characteristics of samples was studied.Firstly,the principle of spectral confocal displacement measurement system is introduced.Based on scalar scattering theory,the axial response of spectral confocal under the influence of surface scattering characteristics is deduced,and the relationship model of scattering influence on displacement measurement is established.Then,the displacement measurement error caused by the peak wavelength curve shift caused by scattering is studied theoretically and simulated.The results show that when the surface roughness of the sample is large,it will produce a large scattering effect,which will lead to a significant decline in measurement accuracy.At the same time,the spectral confocal shift measurement is affected by the incident characteristics of each wavelength.In order to correct the influence of scattering,a multivariate scattering correction method combined with generalized regression neural network(GRNN)is proposed to process spectral data,and a scattering correction algorithm model is established.Finally,an experimental platform was built,and samples were selected for displacement measurement experiments.The experimental results show that the measurement performance of the system decreases with the increase of roughness.For the sample with roughness of 20 nm,the maximum displacement measurement error is reduced from 12.6μm to 1.9μm,and the average displacement measurement error is reduced from 8.1μm to 0.86μm,which improves the displacement measurement accuracy and verifies the correctness of theoretical analysis and the effectiveness of the proposed scattering correction method.This research result has certain reference significance for improving the accuracy of spectral confocal displacement measurement system.Objective Displacement measurement technology can be used to detect surface morphology,film thickness,three-dimensional structure of living c

关 键 词：光谱共焦 表面散射特性 位移测量 光谱数据处理 多元散射校正 

分 类 号：O433.1[机械工程—光学工程]