Explosive Detecting Technology Based On Wide-band THz Technology

Terahertz radiation is electromagnetic radiation whose frequency range liesfrom0.1to10THz. THz radiation is a novel, with many unique advantages ofradiation sources. Terahertz technology is a very important cross-frontier totechnological innovation. It provides a new opportunity for development totechnological innovation, and the development of the national economy andnational security. Terahertz technology has many new characteristics. In recentdecades, with the rapid development of electrical and ultrafast optics Terahertztechnology, The terahertz technology to detect explosives has been widely used.Terahertz spectroscopy has become a popular method for the investigationand characterization of a wide range of molecular solids. This is primarily due tothe fact that many materials have distinctive THz absorption features that aredirectly related to their crystal structure. Over the last decade, the developmentof THz pulsed spectroscopy, using ultra-short pulses of coherent THz radiation,has greatly facilitated experimental access to this range of the electromagnetic spectrum. The THz spectral features can be used in applications such asdetecting and identifying solid-state explosives.In the first chapter of thesis mainly introduces terahertz many of thefeatures and use certain features to detect the unknown explosives. Severalcommon explosives detection equipment and technical are introduced. Usingterahertz technology has many advantages over others technologies. Itsummarizes the major domestic and international major research institutionsusing terahertz technology to detect explosives.The second chapter classify the generation of THz. THz is divided intonarrow-band terahertz, terahertz, and ultra-wide-band terahertz pulse terahertz,and compare the detection of terahertz pulses.It mainly introduces theexperiment photoconductive antenna terahertz sources.The third chapter introduces the terahertz time-domain spectroscopy and itsanalysis of the principle and characteristics.The fourth chapter describes the use of terahertz time-domain spectroscopy(TDS) detection of common explosives in less than3THz band analysis using wavelet transform to optimize the results. And Fourier transform infraredspectroscopy is introduced.The fifth chapter describes the common explosives(TNT,PETN,HMX,RDX)under the wide-band terahertz pulse terahertz spectroscopy, which extendedfrequency range.The last chapter summarizes this whole thesis, and look forward to thefuture of the THz spectra technology.