太赫兹脉冲扫描成像算法及其应用

发布时间：2018-02-12 22:00

本文关键词： 太赫兹成像太赫兹成像算法太赫兹脉冲时域光谱太赫兹应用　出处：《电子科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：太赫兹技术是未来科研及应用发展的新方向。太赫兹波段电磁波处于可见光波和微波之间的空白区,本身具有巨大的发展空间,这使得太赫兹科学技术受到国内外许多方面的关注。飞秒激光的发展使得光导天线成为稳定、可靠的太赫兹脉冲辐射源,为太赫兹成像技术奠定了较好的基础。太赫兹脉冲成像技术是太赫兹科学与技术中颇具潜在发展可能的一个应用领域,多个国家将太赫兹成像技术作为一个重要的战略发展方向,其未来对整个世界产生的影响将不可小觑。本课题以太赫兹脉冲时域光谱成像算法及应用为中心。首先通过调研来研究太赫兹时域成像技术与频域成像技术的发展状况及发展方向。介绍所使用的太赫兹脉冲时域光谱仪系统及实验中扫描成像系统工作原理。对太赫兹脉冲成像各种模式的实现及使用时各个模式的最佳适应条件进行了研究。其次,研究太赫兹脉冲扫描成像数据处理算法。推导太赫兹脉冲时域数据处理理论,对其中提及的双高斯滤波器及去卷积技术进行算法实现。尝试实现太赫兹相位成像及太赫兹三维成像,并用相关实验对两种成像模式进行了验证。再次,使用太赫兹脉冲扫描成像数据处理分析算法进行实验样品成像数据分析。最后,设计拥有自主版权的太赫兹脉冲成像数据分析平台,并通过实验验证该数据处理平台。具体工作如下:(1)讨论太赫兹脉冲成像系统中的多种成像模式。针对不同的样品选择不同的成像模式,同一个样品采集不同的位置的信息时也可以选择不一样的成像模式来更好的进行分析。这部分为太赫兹脉冲成像数据分析奠定基础。(2)详细推导太赫兹脉冲时域成像数据处理理论、双高斯滤波器以及去卷积算法实现理论。针对本论文中尝试的新成像方式相位成像以及三维成像进行描述以及介绍,并通过对应的实验验证提出的成像方式。通过相位成像可得到更加精准的样品重构图像,而三维成像模式下得到的三维重构图有助于分析样品内部结构状况。(3)利用太赫兹成像技术对两种样品,小麦种子以及人体牙齿进行成像及图像重构分析。通过太赫兹成像技术中的切片峰峰值成像模式对小麦种子进行分析,获得在不同时间切片位置处的二维重构图像。从不同切片位置的重构图像出可依稀辨别出种子下方的缝隙结构,并通过比较中层时间切片位置处三颗种子的切片峰峰值二维重构图像可判断种子对应的状态,该结果获得认可。由于牙齿体型不均匀,其对微弱太赫兹辐射散射较多,以致本文中的牙齿成像结果不太理想。虽然如此,但通过实验结果还是可以区别出病牙和正常牙齿。(4)基于数学工具MATLAB设计属于自己的可扩展数据处理分析平台。对该数据分析平台进行结构设计,并添加附加功能。在新设计的平台上调用太赫兹时域光谱成像系统中的成像数据文件进行数据处理,验证该平台的可用性。总而言之,本论文对太赫兹脉冲时域光谱成像算法及应用进行了的研究。采用实验验证理论的方式,对相位成像及三维成像算法的可行性进行了验证。本课题研究为太赫兹成像技术的下一步发展提供了参考,具有意义。
[Abstract]:Terahertz technology is a new direction for the future research and application development. THz electromagnetic wave in visible light wave and microwave the space itself has a huge space for development, which makes the Terahertz Science and technology has attracted much attention of many aspects at home and abroad. The development of femtosecond laser makes the photoconductive antenna become stable, reliable terahertz radiation source, which a good foundation for THz imaging. Terahertz pulsed imaging technology is a field of application can be a potential development of Terahertz Science and technology, many countries will terahertz imaging technology as an important strategic direction of development, affecting the future of the whole world have to be underestimated. The THz pulse time-domain spectral imaging algorithm and Application Center. Firstly, through the research on terahertz time domain and frequency domain imaging imaging technology development Development status and development direction. The working principle of scanning imaging system using the terahertz time-domain spectroscopy system and experiments. The best fit conditions on the implementation and use of terahertz pulse imaging modes of each mode was studied. Secondly, the research of terahertz pulse imaging data processing algorithm. Derivation of terahertz pulse time domain data processing theory the double filter, Gauss mentioned and deconvolution technique algorithm. Try to achieve terahertz phase imaging and THz imaging, and related experiments on the two imaging mode is verified. Thirdly, using terahertz pulse analysis algorithm experiment sample imaging data analysis of imaging data processing. Finally, the design of terahertz pulse imaging data copyright analysis platform, data processing platform and the specific work is verified by experiments. Are as follows: (1) discuss the various imaging modalities of terahertz pulse imaging system. Choose different imaging modes for different samples, the same samples were collected in different locations of information can also be analyzed to choose different imaging mode to better. This part is called the terahertz pulse imaging data analysis (lay the foundation. 2) time domain imaging data processing theory derived terahertz pulse, double Gauss filter and deconvolution algorithm theory. Description and introduction to new imaging methods, this paper attempts to phase imaging and 3D imaging, imaging method and verified by experiments. The corresponding proposed sample image reconstruction more accurate by phase imaging. The 3D reconstruction by 3D imaging mode is helpful to the analysis of the internal structure of the samples. (3) of the two samples using terahertz imaging technology, small Wheat seed and human teeth were analyzed by imaging and image reconstruction. Peak slice imaging mode THz imaging technology in the analysis of wheat seeds, to obtain two-dimensional images at different time slice position. From the reconstructed image can distinguish the thin slot structure under different seed slice position, and to determine the corresponding seed the state with the slice peak two-dimensional reconstruction image comparison middle time slice position three seeds, recognized the results. Because of the tooth body evenly, the weak scattering of terahertz radiation is more, so that the dental imaging results are not ideal. In spite of this, but by the results of the experiment can still distinguish tooth disease and the normal teeth. (4) MATLAB mathematical tools to design their own scalable data processing platform based on the analysis of data analysis platform structure Design, and add additional functionality. The imaging data file in a new design platform called terahertz time-domain spectral imaging system for data processing, to verify the availability of the platform. In a word, the research on terahertz time-domain spectral imaging algorithm and the application of the theory. By experimental verification, the feasibility of phase imaging and 3D imaging algorithm is verified. The research for terahertz imaging technique for the next step in the development of reference, has the significance.

【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O441.4

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