太赫兹炸药探测方案毕业设计.doc

毕业设计说明书
太赫兹炸药探测方案设计
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2012年6月
太赫兹炸药探测方案设计
摘要
近十几年来,太赫兹技术随着超快激光技术的进展而得到蓬勃发展。-10太赫兹区间的远红外电磁辐射,其波段位于微波和红外光之间。太赫兹时域光谱技术是20世纪80年代以来发展起来的一种新型光谱测量技术。它以太赫兹辐射作为探测源,利用电光采样或光电导采样方法直接记录太赫兹辐射电场的振幅时间波形,通过傅立叶变换得到测量信号振幅和相位的光谱分布,进而获得材料在太赫兹波段的吸收和色散等信息。许多物质在THz波段的光谱包含着丰富的物理和化学信息,因此研究物质在该波段的光谱具有重要意义。太赫兹辐射对炸药所处的状态非常敏感,温度的不同和晶型的不同都会在太赫兹光谱中有不同反应,不同的炸药样品吸收特征也有所差别,可用于炸药的精细结构监测分析,利用太赫兹光谱技术可以测得爆炸物的特征吸收光谱,由此识别爆炸物种类,进而分析物质的物理化学特性,为爆炸物的探测提供了一种全新的方法。
本论文首先介绍了THz波的特性及其在爆炸物探测技术上所存在的优势,并对近年来国内外利用THz-TDS技术探测炸药领域的研究进展进行了详细的综述。其次,对THz的产生和探测技术进行了归类和介绍。对实验中使用的透射型THz-TDS系统的光路系统及其主要工作原理和数据分析方法进行了介绍。然后,利用THz-TDS技术进行了炸药THz吸收光谱的探测,并对使用小波变换对THz-TDS系统所测数据进行了降噪分析。
关键词:太赫兹,爆炸物,探测技术,小波变换
THZ EXPLOSIVE DETECTION SCHEME DESIGN

ABSTRACT
The THz technology is developed with the development of ultra-fast laser in recent years, Terahertz radiation usually refers to the wavelength in terahertz to 10 terahertz range of far infrared ic radiation, the waveband is located between in the microwave and infrared radiation. THz time-domain spectroscopy is a powerful tool development in 1990s for spectroscopy measurement. This technique can record the amplitude of the wave by electro-optical or photoconductive sampling. After fast Fourier transform, the amplitude and phase of the THz pulse wave is given, then the refractive index and absorption of the material in THz region is extracted. Terahertz radiation to the explosive which state is very sensitive, different temperature and different type in terahertz spectroscopy has different reaction, the different absorption characteristics of explosive samples also difference can be used for monitoring and analysis of the fine structure of explosive, Because of the vibration and rotation energy levels of many explosives lie in the THz wave band, the characteristic absorption spectra of the explosives which can be detected by the THz technology can be used to analyze the physical and chemistry characteristic. The THz te