基于正交全息的台阶相位原位重建  

In-situ reconstruction of step phase based on orthogonal holograms

作　　者：郝爱花 黄静燕 张世纪 王志俊 王笑龙 HAO Aihua;HUANG Jingyan;ZHANG Shiji;WANG Zhijun;WANG Xiaolong(School of Electronic Engineering,Xi’an University of Posts&Telecommunications,Xi’an 710061,China)

机构地区：[1]西安邮电大学电子工程学院,西安710061

出　　处：《物理学报》2025年第6期79-86,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12304329)资助的课题.

摘　　要：滤波技术是数字离轴全息精确相位重建的关键.由于CCD分辨本领和离轴全息技术本身的限制,台阶型相位物体在全息滤波过程常常伴随频谱损失、频谱混叠,以及全息图被截取非整数周期时的频谱泄漏问题.目前频域滤波在针对单幅全息图的自适应滤波方面已有很多研究,但上述问题都无法得到根本解决.本文在分析一维空间滤波成像特性的基础上,提出了一种在对两个正交全息图分别进行一维傅里叶变换和一维全谱滤波的基础上,对重构的物光波利用泊松方程进行精确相位解缠绕的相位原位重建技术.该方法从根本上避免了滤波引起的频谱损失、频谱混叠和频谱泄漏问题,且运算过程简单、重建精度高、适合于任何形状台阶物体的三维轮廓重建,为离轴全息的高精度相位重建提供了切实可行的途径.Filtering technology is the key to accurate phase reconstruction in off-axis digital holography.Due to the limitations of resolution of charge coupled device(CCD)and off-axis digital holography itself,the filtering process of the step-phase objects is often accompanied by spectral loss,spectral aliasing and spectral leakage when non-integer periods are intercepted.At present,much research has been done on adaptive filtering in the frequency domain,but the above problems have not been fundamentally solved.In this work,the influence of spatial filtering on the accuracy of step-phase reconstruction is first analyzed theoretically.The analysis shows that even if the size of the filter window is equal to the sampling frequency of the CCD,the reconstructed object cannot retain all the spectral information of the object due to the limitation of the resolution power of the CCD itself.In addition,in the off-axis holographic recording process,considering the interference of zeroorder terms and conjugate terms,the actual filter width is usually only 1/24 of the sampling frequency of the CCD,at which the average absolute error of the step is about 10%of the height of the step,the oscillation is relatively severe,and after further smoothing filtering,the details of the object are lost,the edge is blurred,and the tiny structure cannot be resolved.Second,according to the definition of discrete Fourier transform,the onedimensional Fourier transform of a two-dimensional function integrates only in one direction,while the other dimension remains unchanged.When performing one-dimensional Fourier transform along the direction perpendicular to the holographic interference fringes and performing one-dimensional full-spectrum filtering,the distribution of reconstructed object light waves in the direction parallel to the fringes follows the original distribution,is not affected by the filtering,and has high accuracy.Therefore,by combining the reconstructed light waves obtained from one-dimensional full-spectrum filtering of two orthogon

关 键 词：数字全息 台阶相位 原位重建 

分 类 号：O43[机械工程—光学工程]