基于环形光瞳滤波器的超分辨数字全息显微成像理论与实验研究

发布时间：2018-05-11 01:19

本文选题：数字全息显微术 + 光瞳滤波器　；参考：《昆明理工大学》2017年硕士论文

【摘要】：数字全息术是一种真正实现物体三维成像与测量的技术,是光学、光电子技术和计算机技术的高度融合。数字全息显微术是数字全息术的一个重要应用领域,它不仅具有非接触、无损伤、全视场、处理灵活、存储方便等优点,还能同时获得三维微结构的强度和相位信息,是近年来显微成像技术的一个重点方向,具有非常广泛的应用前景。传统光学显微镜的成像分辨率,由于受到光学衍射效应的影响,其分辨率存在极限。这对于目前越来越深入的生命科学研究领域显然是不能满足的。因此进一步提高光学显微系统的分辨率,对于探索更精细的细胞结构和功能是很有必要的。本文根据光波标量衍射理论,提出了在数字全息显微系统物光中加入幂级数光瞳滤波器或环形光瞳滤波器的成像新方法。分别从理论分析、数值模拟和实验验证等方面对这种振幅型光瞳滤波器的超分辨成像方法进行了研究。文中的对分辨率的检测近似为只对光强的检测而不讨论对相位的检测。首先给出幂级数光瞳滤波器和环形光瞳滤波器的光瞳函数,然后根据标量衍射理论推导出这两种光瞳滤波器的夫琅禾费衍射分布函数,其分布特点由1阶贝塞尔函数描述。然后根据推导出的光场分布函数和光强分布函数,通过MATLAB编程画出幂级数光瞳滤波器和环形光瞳滤波器的透过率分布和光这两种滤波器的二维光强分布、三维光强分布。光学显微镜的分辨率与艾里斑尺寸密切相关。参照光学超分辨影响因素,讨论了衍射分布的主瓣强度、主瓣宽度和旁瓣强度,分析斯特雷尔比S、最大旁瓣强度比M、分辨参量G和分辨率提高倍数。通过模拟出两个点像叠加后的光强分布,用图像直观地说明,借助这两种光瞳滤波器可以有效提高显微系统的分辨率。最后设计出数字全息显微系统的Mach-Zehnder干涉光路,在物光路中加入环形分布的振幅型光瞳滤波器,并利用预放大的方法拍摄美国空军标准(USAF1951)分辨率板、植物细胞和人血细胞。将拍摄到的全息图取其+1级进行再现,并对比不同环形孔径比下的再现像。实验证明,加入环形光瞳滤波器可以使较大细胞的高频部分更加明显,但对于实现超分辨效果不甚理想。
[Abstract]:Digital holography is a technology that truly realizes three-dimensional imaging and measurement of objects. It is a high fusion of optics, photoelectron and computer technology. Digital holography microscopy is an important application field of digital holography. It not only has the advantages of non-contact, no damage, full field of view, flexible processing, convenient storage and so on, but also can be obtained at the same time. The intensity and phase information of the three-dimensional microstructures is a key direction of the microimaging technology in recent years. It has a very wide application prospect. The resolution of the traditional optical microscope has the limit of resolution due to the influence of the optical diffraction effect. It is obvious that it is becoming more and more deep in the field of life science research. Therefore, it is necessary to further improve the resolution of optical microscopy, and it is necessary to explore more fine cell structure and function. Based on the theory of light wave scalar diffraction, a new method of adding a power series pupil filter or ring pupil filter to the physical light of a digital holographic microscopic system is proposed. On the basis of analysis, numerical simulation and experimental verification, the super-resolution imaging method of this amplitude type pupil filter is studied. The detection of resolution in this paper is approximate to the detection of light intensity only without discussing the detection of phase. First, the pupil function of the power series pupil filter and the ring pupil filter is given, and then it is based on the pupil function of the power series pupil filter and the ring pupil filter. The scalar diffraction theory derives the Fraunhofer diffraction distribution function of these two pupil filters. The distribution features are described by the 1 order Bessel function. Then, according to the deduced light distribution function and the light intensity distribution function, two kinds of power series pupil filter and ring pupil filter are drawn through MATLAB programming. The resolution of the two-dimensional light intensity distribution of the filter, the three-dimensional light intensity distribution. The resolution of the optical microscope is closely related to the size of the Airy spot. Referring to the influence factors of optical superresolution, the main lobe strength, the width of the main lobe and the sidelobe strength of the diffraction distribution are discussed, and the veonstray Erby S, the maximum sidelobe intensity ratio M, the resolution parameter G and the resolution increase multiplier are analyzed. The light intensity distribution after two points is simulated, and the image can be intuitively illustrated by the images. With the help of the two pupil filters, the resolution of the micro system can be improved effectively. Finally, the Mach-Zehnder interference optical path of the digital holographic microsystem is designed, and the amplitude type pupil filter of the ring distribution is added to the physical optical path, and the pre amplification method is used. The USAF1951 resolution plate, plant cell and human blood cell were taken. The hologram was reconstructed at the +1 level, and the reproduction image under the different ring aperture ratio was compared. The experiment showed that the high frequency part of the larger cell could be more obvious by adding the ring pupil filter, but it was not very effective for the superresolution effect. Think.

【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O438.1

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