Terahertz Time-domain Spectroscopy With Stealth Materials

One application of the terahertz radiation technology in military and space is stealthy technology and anti-stealthy technology. Nowadays, many countries are working at researching for new materials as well as improving traditional stealthy materials. Although the application of stealthy material in wave band has reached a certain degree of success, such as infrared ray and microwave, it is still a blank in the THz wave band.In this thesis, the key point is about the exploration about absorption and stealthy materials through several experiments, and having got the spectrum from 0.2 THz to 2.5 THz of several kinds of crystal compounds, metallic oxide and shielding cloths were got. I discussed the shielding effect by the different grades and their potential value, and these results maybe bring some important information on the basic research on terahertz absorption and stealthy materials. In the first chapter of this paper, I introduced the development of stealthy generation technology and materials at home and abroad. Besides, the technology and detection for terahertz wave, the purpose and significance of topics are also introduced.The second chapter was mainly about terahertz time-domain spectrum system. Extraction method of related material parameters was explained.The third chapter was mainly about the experiment process and the means to deal with the data. In the fourth chapter, measurement results of the terahertz spectra of crystal compounds were discussed. The results showed that these crystal compounds had a good absorbency to terahertz radiation, among which mirabilite, bluestone and alum had better absorbency. This provides possible evidence for the research of absorbent materials.In the fifth chapter, measurement results of the terahertz spectra of four kinds of stealthy material were discussed. Results showed that these four shielding cloths had a good shielding effect to terahertz radiation; especially the gray shielding cloth. If they are applied on aerospace or military equipments, there would be some difficulties for terahertz detection,The sixth chapter mainly talked about the measurement results of the terahertz spectra of seven kinds of metallic oxide. The results showed that magnesia, tungsten trioxide and lead oxide had better effect.In the last chapter, I gave a summary on the work of experiment results. The prospects of the terahertz science and technology for antagonism and stealthy technology were discussed.