太赫兹主动关联成像技术研究
文献类型：学位论文
| 作者 | 闫昱琪 |
| 文献子类 | 硕士 |
| 导师 | 赵成强 |
| 关键词 | 太赫兹 Terahertz 关联成像 Ghost imaging 赝热光源 Pseudo-thermal light 压缩感知算法 Compressed sensing |
| 其他题名 | Research on the Terahertz Active Ghost Imaging Technology |
| 英文摘要 | 太赫兹辐射作为一种特殊的电磁波，具有十分重要的学术价值和广阔的应用前景。由于太赫兹波的各种优良特性，太赫兹成像成为了一种新兴的成像技术，从二十一世纪开始得到了各国学者的广泛关注和深入研究。如今，太赫兹成像技术已经在国家安全、生物医学研究、航空航天等领域逐渐发挥出了它的价值。为进一步发掘太赫兹成像技术的潜力，提高太赫兹成像的精度和速度，本论文提出了一种新型的太赫兹成像方式—太赫兹主动关联成像技术，并通过仿真和实验证明了此技术在成像速度和分辨率方面的优势，旨在解决目前太赫兹成像中成像分辨率低、速度慢的问题。本论文主要包含以下内容： 第一章首先阐述了太赫兹波的性质、独特优势以及太赫兹成像技术在各领域的应用前景，并且通过太赫兹成像技术的国内外研究现状指出了现阶段研究出高速、高分辨太赫兹成像技术的重要性。然后介绍了关联成像技术的原理和研究现状，阐明将关联成像应用于太赫兹成像当中的优势。 第二章详细介绍了太赫兹主动关联成像系统设计的理论基础—压缩感知算法和可预置赝热光源的单臂关联成像方式，通过它们的原理及优势提出了太赫兹主动关联成像系统的设计思路，并且在理论上阐述了此系统在太赫兹成像速度和分辨率方面的优势。然后根据设计思路分为两个步骤对太赫兹主动关联成像系统进行了具体设计。 第三章主要通过数值模拟量化分析了系统各因素（成像距离、随机图形尺寸、采样次数等）对成像质量的影响，为太赫兹主动关联成像实验装置的器件选择和实验方案提供了最优指标，证明了该系统的可行性。仿真结果表明：采用压缩感知算法可以在低采样数的条件下更准确地恢复出待测目标；双调幅板距成像面越近，成像质量越高；调幅板上不透明随机图形的最佳尺寸为6 mm。另外，本章还通过仿真优化了双调幅板的运动策略，以提高采样矩阵的随机性，降低了系统成像所需的采样次数，进一步提高成像速度。 第四章对搭建的成像实验装置、各器件的参数性能以及软件控制系统进行了介绍，实验采用波长为3 mm的太赫兹辐射源和一个太赫兹单点探测器，成功获得了30 pixel×30 pixel的太赫兹图像。实验结果表明：在单个像素大小为1.8 mm的条件下，采用压缩感知算法重建出的目标图像分辨率可以达到4 mm，且系统成像时间由调幅板的电机转速决定。另外，实验中还通过对金属钥匙进行成像，验证了系统的实物成像能力。最后，分析了太赫兹主动关联成像系统在成像精度、速度方面的潜力和优势，证实了利用此成像方式实现高速、高分辨太赫兹成像的可行性。; As a special electromagnetic wave, Terahertz radiation has very important academic value and wide application prospect. Its excellent properties make the Terahertz imaging technology become a new imaging technology, which has been widely concerned and studied by scholars from the 21st century. Today, Terahertz imaging technology has gradually played its value in the fields of national security, biomedical research, aerospace and other fields. In order to further explore its potential and improve accuracy and speed of Terahertz imaging, a new method - Terahertz active ghost imaging technology is proposed in this paper. The advantages of this method in imaging speed and resolution are proved by simulation and experiment. The aim is to solve the problem of low resolution and speed in the present Terahertz imaging. The main contents of this paper are as follows: In Chapter1, the properties, unique advantages of THz and the application prospect of Terahertz imaging technology in various fields are described. And the importance of high speed and high resolution terahertz imaging is pointed out at present by the research status of Terahertz imaging technology at home and abroad. And then, the principle and research status of the ghost imaging technology are introduced, and the advantages of applying ghost imaging to Terahertz imaging are illustrated. In Chapter2, the theoretical basis of Terahertz active ghost imaging system - compression sensing algorithm and the single arm ghost imaging mode based on preset pseudo thermal light are introduced in detail. And through their principles and advantages, the design idea of Terahertz active ghost imaging system is proposed. Then, according to the design idea, it is divided into two steps to design the Terahertz active ghost imaging system, which has a great advantage in imaging speed and resolution. In Chapter3, the influence of various factors in the system (imaging distance, size of random pattern, sampling times, etc.) on imaging quality is analyzed by numerical simulation, in order to provide optimal indexes for the device selection and experimental scheme. The simulation results show that the compressed sensing algorithm can recover the target more accurately under the condition of low sampling times. The nearer the imaging distance, the higher the imaging quality. And the best size of the random pattern on the amplitude plates is 6 mm. In addition, we optimize the motion strategy of the double amplitude plates by simulation, in order to improve the randomness of the sampling matrix and reduce the sampling times required in imaging, further improving the imaging speed. In Chapter4, the experimental equipment, parameter performance of each device and the software control system are introduced. And practical experiment is carried out. The experimental results show that the imaging resolution with the compressed sensing algorithm can reach 4 mm, when the single pixel size is 1.8 mm. And the imaging speed is determined by the motor speed of amplitude plates. In addition, the actual imaging ability of this system is proved by imaging experiment on the metal key. Finally, the potential and advantages of Terahertz active ghost imaging system in imaging accuracy and speed are analyzed. And the feasibility of high speed and high resolution Terahertz imaging with this method is proved. |
| 学科主题 | 光学 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/31090]  |
| 专题 | 中国科学院上海光学精密机械研究所 |
| 作者单位 | 中国科学院上海光学精密机械研究所 |
| 推荐引用方式 GB/T 7714 | 闫昱琪. 太赫兹主动关联成像技术研究[D]. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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