复杂环境下的激光成像及传输技术研究

发布时间：2017-12-26 16:37

本文关键词：复杂环境下的激光成像及传输技术研究　出处：《北京交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：激光技术如今被广泛应用在激光雷达、激光测距、激光遥感成像及水下光学成像等领域,然而激光在大气及水下等复杂环境传输过程中,不可避免的要受到介质的影响,尤其在大气中传输时,由于大气吸收、散射以及湍流等效应会使光信号衰减、光强起伏及相位起伏等,这些问题限制着激光技术的进一步推广应用。因此,对于激光在复杂环境下的传输及成像问题的研究具有重要的意义,论文的工作围绕该问题展开,主要完成了以下的工作:1、完成了畸变图像的实时修复,并解决了复杂环境成像分辨率低的问题。对于消除图像畸变的方法进行了理论研究,完成了消除图像畸变的实验设计,搭建三波混频光学相位共轭消除图像畸变的实验系统。在实现12线/mm高分辨率的同时,首次将光学增益提升至17.8dB;本文利用三波混频来获取相位共轭光,该方法光路简单、转换效率高、响应速度快,且所需泵浦功率低,对今后实时消除畸变具有一定的指导意义。2、提出了水下图像传输所面临的分辨率和传输距离不可兼得问题的解决方案。首次将水下关联探测及水声通信结合(发明专利申请号:201611183949.5),设计水下关联图像远程加密传输装置,利用光学成像实现高分辨率,声学传输实现远距离,关联探测实现加密;该方案不仅能保持光学成像高分辨率的优点,同时还可解决光学信号在水下传输距离短等问题。3、基于Kolmogorov理论,利用相位屏方法,对激光在湍流大气中的传输特性进行了研究,计算不同条件下的光强起伏及相位起伏,且分析了相位共轭技术修复大气畸变的可行性。利用三波混频光学相位共轭技术响应快、光路简洁、实时修复等特点,有望将其使用于水下、大气及生物组织等复杂环境,消除因介质带来的畸变,实现复杂环境下的高分辨率成像。
[Abstract]:Laser technology is now widely used in laser radar, laser ranging, laser remote sensing imaging and underwater optical imaging etc. However, laser in air and underwater complex environment in the process of transmission, influence inevitably by the media, especially the transmission in the atmosphere, due to atmospheric absorption, scattering and turbulence effects will make the optical signal attenuation, light intensity and phase fluctuations, these problems restrict the further application of laser technology. Therefore, it is significant to research the problem of laser transmission and imaging in complex environment, this thesis focuses on the problems, mainly completed the following work: 1, completed the real-time repair image distortion, and solves the problem of low resolution imaging in complex environment. The method of eliminating the image distortion is studied theoretically, and the experimental design of eliminating the image distortion is completed. The experimental system of eliminating the image distortion with the three wave mixing optical phase conjugation is built. In the realization of the 12 line /mm high resolution at the same time, for the first time will enhance the optical gain to 17.8dB; using three wave mixing to obtain the phase conjugate light, the method of simple optical path, high conversion efficiency, fast response speed, and the required pump power is low, the future real-time eliminate distortion has certain guiding sense. 2. A solution to the problem of the resolution and transmission distance of underwater image transmission is proposed. For the first time with underwater acoustic communication and correlation detection (patent application number: 201611183949.5), remote transmission device encryption related image design of underwater high resolution optical imaging, acoustic transmission remote detection, correlation encryption; advantages of the scheme can not only maintain the high resolution optical imaging, but also can solve the problem the optical signal in underwater short distance transmission etc.. 3, based on Kolmogorov theory, the transmission characteristics of laser in turbulent atmosphere were studied by phase screen method. The intensity fluctuation and phase fluctuation under different conditions were calculated, and the feasibility of phase conjugation technology to repair atmospheric distortion was analyzed. The three wave mixing optical phase conjugation technology has the characteristics of fast response, simple optical path and real-time repair. It is expected to be applied to complex environment such as underwater, air and biological tissue, to eliminate the distortion caused by the medium, and achieve high resolution imaging in complex environment.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN24

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