纯随机相位板散斑去相关光学相干层析成像  

Speckle Decorrelation Optical Coherence Tomography Using Pure Random Phase Plate

作　　者：屈慧 汪毅[1] 娄世良 徐玉帅 王露桐 蔡怀宇[1] 陈晓冬[1] Qu Hui;Wang Yi;Lou Shiliang;Xu Yushuai;Wang Lutong;Cai Huaiyu;Chen Xiaodong(Key Laboratory of the Ministry of Education on Optoelectronic Information Technology,College of Precision Instrument and Opto-Electronics Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学精密仪器与光电子工程学院光电信息技术教育部重点实验室,天津300072

出　　处：《光学学报》2023年第1期82-90,共9页Acta Optica Sinica

基　　金：国家重点研发计划(2017YFC0109901);天津市自然科学基金(15JCQNJC14200)。

摘　　要：光学相干层析成像(OCT)的图像质量会受到散斑噪声的影响,限制了OCT在临床诊断中的应用。叠加取平均是一种降噪的常用方法,作为相干噪声,散斑降噪的关键在于降低用于叠加的图像之间的散斑相关度。提出了一种基于纯随机相位板的散斑去相关OCT系统(PSD-OCT)。利用纯随机相位板调制样品光的波前相位以实现散斑去相关,从而为采用叠加取平均降低OCT图像噪声的方法提供低相关数据。成像实验证明了纯随机相位板能够降低散斑相关度,提升叠加图像的散斑信噪比,使得生物样品的精细结构更为清晰明显。与传统OCT的相关叠加相比,PSD-OCT的去相关叠加可以大幅降低散斑噪声从而增强OCT图像的视觉可见性,且无需搭建复杂系统,具有广泛的生物医学成像应用前景。Objective Optical coherence tomography(OCT) is a non-invasive optical imaging technology. In recent years, it has become a research hotspot of biological imaging and has been widely used in the field of medical diagnosis. As an imaging technology based on the principle of low coherent light interference, OCT is susceptible to speckle noise. Speckles will destroy details of OCT images and reduce image quality, which imposes significant limitations on the clinical application potential of OCT. Superposition is a common method to reduce additive white noise. However, speckle noise belongs to the multiplicative noise. In order to suppress speckles more effectively, it is necessary to use speckle decorrelation technology to reduce the speckle correlation between images for superimposition, which is called the decorrelation superimposition method. Decorrelation superimposition can improve the speckle signal-to-noise ratios of superimposed images. Up to now, researchers have proposed a variety of speckle decorrelation technologies, but they face the following limitations: the number of available decorrelation images is limited;the overall system is bulky, complex, and expensive;the transmitted light power is greatly lost, and illumination variability during two-dimensional scanning is introduced. In this study, a speckle decorrelation OCT system using a pure random phase plate(PSD-OCT) is reported. The system uses a tailored pure random phase plate(PRPP) to achieve speckle decorrelation, which can avoid the loss of light power and the introduction of illumination variability, and has a simple and low-cost structure. PSD-OCT helps obtain low-noise imaging results.Methods The PSD-OCT system is built based on swept-source OCT. The system uses a PRPP to modulate the wavefront phase of the sample light, and changes the gray value characteristics of speckles when images for superimposition are collected to realize speckle decorrelation, so as to provide low correlation images for decorrelation superposition method and reduce

关 键 词：成像系统 成像系统噪声 光学相干层析 散斑 随机相位板 波前调制 

分 类 号：O436[机械工程—光学工程]