叠层成像技术成像机制的理论分析与实验研究

发布时间：2018-04-10 20:55

本文选题：叠层成像 + 相干衍射成像　；参考：《西安电子科技大学》2016年博士论文

【摘要】：叠层成像是近十年来新兴的一种计算成像技术。该方法通过相位恢复迭代算法,寻找样本在重叠扫描模式下,满足多幅远场衍射强度图像约束的唯一复数解。该成像技术的分辨率不受光学聚焦器件的限制,可突破系统衍射极限,获得超高分辨率成像。在一些需要从相位分量缺失的强度图像中恢复重建光波衍射信息的高分辨率和三维成像领域,叠层成像具有天然的优势和潜在的应用前景。本文围绕叠层成像的成像机理,以及它在相干衍射成像、一般光学成像及计算全息中的应用,展开了深入的研究,并对叠层成像的缺陷和不足提出了相应的解决方法。本文的主要内容如下：1)简要描述叠层成像的理论背景。首先,基于光波的标量衍射理论和傅里叶光学理论,对光波衍射现象,透镜的傅里叶变换作用及成像原理进行数值计算,并分析衍射受限光学系统成像分辨率存在极限的原因。其次,介绍通过干涉获取光波复振幅的全息术,并用计算生成全息图的光电再现实验验证衍射数值计算和全息成像理论的正确性。最后,介绍光相位非干涉获取的概念和相位恢复算法的数学基础——信号复原的反卷积滤波实现和迭代搜索实现理论,以及叠层成像所采用的迭代反卷积滤波器——增量维纳滤波。2)研究相干衍射叠层成像技术。从相干衍射成像的基本原理出发,详细分析传统相干衍射成像对样本孤立性要求和解模糊的产生机理。之后,仿真模拟相干衍射叠层成像使用光探针样本进行重叠扫描,采集记录多幅衍射强度图样,再通过迭代傅里叶变换和增量维纳滤波实现样本恢复重建的过程。定性解释叠层成像通过重叠扫描消除传统相干衍射成像的孤立样本限制和解模糊的原理,并对其中一些关键参数对重建成像的影响做出数值分析。最后,对相干衍射叠层成像检测运动样本的成像过程进行建模仿真,研究表明,由于相干衍射叠层成像图像记录时间长,采集效率低下,运动使重建像出现扭曲、模糊和噪声,像质与曝光积累时间内的样本运动幅度成反比。提出并验证了加入随机相位调制板对光探针调制,可以改善由样本运动引起的重建像降质,提高相干衍射叠层成像应对运动目标的能力,一定程度上解决其只能应对静止或低速目标的问题。3)研究傅里叶叠层成像技术。首先,分析傅里叶叠层成像采用倾斜入射平面波照射样本,使样本频谱与系统相干传递函数之间发生相对移动,从而实现频谱域扫描,并获得不同区域频谱对应样本强度像,再通过相位恢复算法,从这些低分辨率强度图像中重建完整样本频谱,进而获得高分辨率样本图像的原理。其次,通过对比傅里叶叠层成像和相干衍射叠层成像的异同,建立两者间的联系,证明傅里叶叠层成像同样必须遵循重叠扫描约束条件。然后借助合成孔径成像理论,定量分析傅里叶叠层成像对光学显微镜数值孔径和分辨率的提高作用。最后,为提高采集和处理的效率及系统的鲁棒性,提出相干多模态傅里叶叠层成像。利用光电调制器件调制相干光束提供相干多模态照明光照射样本,使所采集强度图像来自多个频谱片段的混叠。之后采用混叠频谱分离的相位恢复算法,从这些图像中计算得到无混叠的样本频谱和高分辨率图像。数值仿真和光电实验证明了,该方法可以显著地减少所需采集图像数量,放松对叠层成像信息复用对于共存多模态的非相干性要求。4)研究叠层成像在集成-全息技术中的应用。首先根据数字全息原理,计算生成三维场景的傅里叶全息图并进行数值重建与分析。其次,介绍非相干光照明下的集成成像技术,针对集成成像与全息相结合而产生的集成-全息技术,仿真实现集成成像单元图像获取、多视点投影图像生成、全息图计算生成和重建的全过程。研究表明现有集成-全息技术对光波场采样稀疏、得到全息图尺寸小、再现像分辨率低且出现视角串扰。然后,推导了多视点投影图像和傅里叶全息图之间的相关性,说明投影图像正是傅里叶全息图经过切割后的子全息图再现像的强度图像,并推导了投影角度和对应子全息图选取位置之间的关系。最后,提出了通过相位恢复算法和子全息图重叠约束条件,从集成成像合成的多视点投影强度图像中重建傅里叶衍射场的计算全息方法,称之为傅里叶叠层集成全息。数值重建和光电再现实验都证明了该方法能够克服传统集成-全息的缺陷,获得高分辨率的三维全息再现像。
[Abstract]:Stack imaging is nearly ten years, a new calculation method of the imaging technique. The phase retrieval algorithm, find the sample in the overlapping scan mode, meet the amplitude of far-field diffraction intensity image constraint solution. The only complex imaging resolution by optical focusing device limitations, can break the diffraction limit system get, ultra high resolution imaging. High resolution and 3D imaging reconstruction field diffraction intensity image information from the phase component missing in some need, laminated imaging has a natural advantage and potential application prospect. This paper focuses on the imaging mechanism of laminated imaging, and its application in coherent diffraction imaging, optical imaging and in CGH, in-depth research, and the corresponding solutions to the defects and shortcomings of laminated imaging is proposed. The main contents of this paper are as follows: 1) a brief description The theoretical background of laminated imaging. Firstly, the light of the scalar diffraction theory and Fourier optics based on the theory of light wave diffraction, numerical calculation and Fourier transform imaging principle of the lens, and the existence of the limit analysis of imaging resolution of diffraction limited optical system from the original. Secondly, through the introduction of the interferometric holography and the complex amplitude of light wave. With the correctness of the numerical calculation and experimental verification of optoelectronic reconstruction diffraction holography theory calculation hologram generation. Finally, the deconvolution filtering optical phase retrieval algorithm and the concept of non phase interference and obtaining the mathematical basis of signal restoration and the realization of the iterative search theory, and iterative deconvolution filter laminated by imaging - increment Wiener filter.2) of coherent diffraction stack imaging technology. Starting from the basic principle of coherent diffraction imaging, a detailed analysis of the traditional phase Dry samples isolated on diffraction imaging requirements for reconciliation mechanism of fuzzy. After the simulation of coherent diffraction imaging using laminated optical probe samples overlap scanning, acquisition and recording of multiple diffraction intensity pattern, and then through the iterative Fu Liye transform and incremental Wiener filter to achieve the process of the restoration and reconstruction. A qualitative explanation of the isolated samples laminated by imaging overlap scanning eliminates traditional coherent diffraction imaging limit principle and fuzzy, and the influence of some key parameters on the reconstruction of numerical analysis. Finally, according to the research on Modeling and simulation, the coherent diffraction imaging process of laminated imaging detection motion samples, due to coherent diffraction stack imaging record for a long time, collection efficiency low movement of the reconstructed image distortion, blur and noise like sample motion amplitude and exposure time of the matter is put forward and inversely. Verify the addition on the optical probe modulation random phase modulation plate, can improve the reconstruction caused by sample motion like the lower quality, improve the ability of coherent diffraction stack motion imaging on the target, to a certain extent to solve it can only deal with static or low speed target.3) of Fu Li leaf stack imaging technique. First, Fourier analysis of stack the oblique incident plane wave imaging layer irradiated samples, the sample spectrum and system causes relative movement between the coherent transfer function, so as to realize the spectral scanning, and obtain corresponding samples in different regions of the spectrum intensity image, and then through the phase retrieval algorithm, the reconstruction of complete sample spectrum from these low resolution images and then obtain the strength, the principle of high resolution images. Secondly, through the comparison of Fourier stack imaging and coherent diffraction imaging of the similarities and differences between layers, establish the connection between proof, Fourier laminated into Like the same must follow the constraints. Then by means of overlapping scanning synthetic aperture imaging theory, quantitative analysis to improve the effect of Fourier laminated imaging of numerical aperture and resolution optical microscope. Finally, in order to improve the efficiency and robustness of the system of acquisition and processing of the proposed coherent multimodal Fourier stack imaging. Coherent beam provides coherent multimodal lighting light irradiation samples using optical modulation, the intensity of collecting images from multiple fragments of spectrum aliasing. The phase spectrum aliasing separation recovery algorithm from these images obtained without sample aliasing and high resolution image. The numerical simulation and experiments show that the photoelectric, this method can significantly reduce the required number of image acquisition, relax on the stack for the coexistence of multi modality imaging information multiplexing non coherence requirement.4) of laminated imaging in integration The application of holographic technology. According to the calculation principle of digital holography, Fu Liye hologram and 3D scene reconstruction and numerical analysis. Secondly, the non coherent integrated light imaging technology, integrated technology for integrated hologram and holographic imaging that combines the simulation of integrated imaging unit multi image acquisition. View projection image generation, the whole process of the generation and reconstruction of CGH. Research shows that the existing integration - holographic technology of light field sampling sparse hologram to be small in size, low resolution of reconstructed image and crosstalk. Then, deduced the correlation between multi view projection image and Fu Liye hologram, that is image projection Fu Liye hologram after cutting the sub hologram intensity image, and deduced the projection angle and the corresponding sub hologram selects the position relationship between. Finally, put forward by phase retrieval algorithm and sub hologram overlap constraint, reconstruction method of computing holography Fourier diffraction field intensity projection image from multi view imaging integrated synthesis, called Fourier stacked integrated holographic reconstruction and optoelectronic reconstruction. Numerical experiments show that this method can overcome the shortcomings of traditional holographic integration to obtain high resolution, three-dimensional holographic reconstructed image.

【学位授予单位】：西安电子科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：O436.1

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