【作者】 单纪鑫；

【导师】 李琦；

【作者基本信息】 哈尔滨工业大学 ， 物理电子学， 2008， 硕士

【摘要】 太赫兹辐射是频率在0.1THz~10THz区间内的远红外电磁辐射,它可以像X射线、可见光等辐射一样,作为物体成像的光源,由于其独特的性质,使得成像技术在安全检查、航天航空领域等方面都有着巨大的应用潜力。目前太赫兹源种类较多,但只有CO2激光泵浦THz激光器具有实验装置紧凑,输出光功率较大、功率较稳定等优点,且已经商品化。为此本论文主要是使用相干公司生产的CO2激光泵浦THz激光器SIFIR-50进行了两个方面的研究:一方面利用P4-42探测器进行了太赫兹扫描反射成像的研究,太赫兹反射成像在安全检测以及反恐等领域有很大的发展潜力,目前尚未见有国内相类似的研究报道;另一方面利用Pyrocom III热像仪进行了太赫兹实时透射成像的研究,目前提高太赫兹成像速度和图像分辨率是国际上对太赫兹成像研究的热点,利用Pyrocom III热像仪构建的实时透射成像系统在成像速度和图像分辨率上有很大的提高。由于太赫兹扫描反射成像系统需要利用锗制分光镜,因此本论文首先研究了在太赫兹波段下半导体锗的透过特性,测得了在6种波长下的透过率,并且分析半导体锗的透过特性与波长之间的关系。本文设计和搭建了太赫兹扫描反射成像系统,进行了改变系统参数对成像效果影响的实验,并且隔着障碍物对一些样品进行反射成像,为今后深入的研究和探索提供了一定的借鉴。另外,本文还搭建了基于Pyrocam III热像仪的实时透射成像系统,自行编写了系统的控制软件。利用该实时透射成像系统对1.63THz和2.52THz分别进行了成像实验研究。最后利用VC++初步编写了太赫兹仿真软件和太赫兹图像处理软件,为太赫兹成像在系统仿真和图像处理方面的研究打下基础。更多还原

【Abstract】 THz radiation is the far infrared radiation whose frequency is between 0.1THz and 10THz, which can be used as imaging light source like X radiation and visible light. Because it has special characteristics, THz imaging technology has tremendous application potentiality in the safety inspection, aerospace and other areas. There are many THz laser sources, but only THz laser pumped by CO2 gas has the advantages of compactness, high and stable output power, which is already widely applied in commerce. In this thesis, the investigations on THz imaging were made in two aspects with CO2 laser-pumped THz laser produced by Coherent Corporation. On the one hand, the THz scanning reflection imaging technique was studied by utilizing the P4-42 detector. The THz reflection imaging has been not reported in domestic newspapers and periodicals at present, but it has tremendous application potentiality in safety inspection, counter-terrorism and other fields. On the other hand, the research on THz real-time transmission imaging was made by using the Pyrocam III thermal imaging system. In recent days, how to heighten the THz imaging velocity and resolution ratio is a focus in the international community, and the transmission imaging system based on Pyrocam III can be a good improvement measure of resolving these two issues.Because the spectroscope made by spectroscope is used in the THz scanning reflection imaging system, the transmission properties of Ge semiconductor in Terahertz region were studied firstly. Transmittances at six different waveforms were measured and the relationship between the transmission and wavelength was investigated.THz reflection imaging system was designed and implemented in this paper. Some imaging experiments were made to analyze how the parameters of system affect the imaging results, and some images were acquired by penetrating through some barriers, which would have some reference values for further research and exploration. Otherwise, the THz real-time transmission imaging system based on the Pyrocam III thermal imaging system was constructed, and the system control software was developed. Utilizing this THz real-time transmission imaging system, some imaging experiments were made at 1.63THz and 2.52THz. At last, the THz imaging simulation software and the THz image processing software were primarily designed utilizing VC++ tool, which would set the foundation for the research on THz imaging system simulation and image processing.更多还原