旋转双散射片散斑抑制方法  

Speckle Suppression Method Based on Rotating Double Diffusers

作　　者：刘芸[1] 刘雨萌 卜佩华 焦明星[1] 邢俊红[1] 翁浚 Liu Yun;Liu Yumeng;Bu Peihua;Jiao Mingxing;Xing Junhong;Weng Jun(School of Mechanical and Precision Instrument Engineering,Xi'an University of Technology,Xi'an 710048,Shaanxi,China)

机构地区：[1]西安理工大学机械与精密仪器工程学院,陕西西安710048

出　　处：《光学学报》2023年第4期96-103,共8页Acta Optica Sinica

基　　金：国家自然科学基金(61805195,51875455);陕西省教育厅重点实验室项目(18JS069);西安市科技计划项目(22GXFW0089)。

摘　　要：提出一种手动旋转双散射片的散斑噪声抑制方法,以一动一静的工作模式获得多幅独立的散斑场,通过多幅再现像叠加实现散斑的抑制。通过理论分析一动一静双散射片和单散射片的时间相关函数,证明一动一静双散射片的去相关速率明显高于单散射片,具有更好的散斑抑制效果。实验上分别进行了不同目数单散射片和双散射片、相同目数单散射片和双散射片之间的对比研究。从散斑对比度结果可以看出,散射片目数越多,再现像叠加数量越多,散斑抑制效果越好,并且双散射片的散斑抑制效果要优于单散射片。以相位光栅为样本,采用一动一静双散射片方式验证了所提方法的可行性,该方法获得了更好的成像效果。Objective Digital holographic microscopy technique has been applied in biomedical imaging,particle tracking,microelectronic system detection,and other fields due to its advantages of non-contact,high precision,and threedimensional imaging.As a light source with high coherence,the laser is widely used.However,coherent noise is inevitably introduced into the imaging,which thus degrades the imaging quality.In order to reduce the speckle noise in holographic imaging,a lot of approaches have been adopted.They are mainly divided into three categories.The first one is based on temporal integration by multiplexing holograms.The second category of digital processing methods is composed of the wavelet transform,neural network,and so on.The third one aims to reduce the coherence of the light source and adopt incoherent holography to suppress speckle.Among them,the rotating diffuser method has been studied due to its simple structure and implementation,and it can obtain multiple uncorrelated holograms by manually or electrically rotating diffusers.Although the electrically rotating diffuser method is suitable for dynamic measurement,it may be affected by vibration and thus brings additional noise to measurement results.Alternatively,the manually rotating diffuser can obtain more stable speckle fields and a better speckle suppression effect.In this paper,the speckle suppression method is proposed which performs by manually rotating double diffusers.Specifically,one diffuser is static,and another diffuser is rotated by manual operation.On this basis,multiple independent speckle fields are obtained.The superimposition of multiple reconstructed images realizes the speckle reduction.Compared with a rotating single diffuser,the proposed method can obtain lower speckle contrast and more accurate measurement results.Methods In theory,the spatio-temporal correlation functions of the dynamic-static and single diffusers are analyzed,respectively.From the theoretical simulation results,it can be concluded that the speckle suppression ef

关 键 词：测量 全息干涉测量 散斑抑制 手动旋转散射片 一动一静双散射片 散斑对比度 

分 类 号：O438[机械工程—光学工程]