The Error Analysis and Experimental Verification of Laser Radar Spectrum Detection and Terahertz Time Domain Spectroscopy
LIU Wen-tao1，LI Jing-wen1，SUN Zhi-hui2
1. Electronic and Information Engineering Institute, Beihang University, Beijing 100191, China 2. Institute of Optoelectronics, Beijing Institute of Technology, Beijing 100081, China
Abstract：Terahertz waves (THz,T-ray) lie between far-infrared and microwave in electromagnetic spectrum with frequency from 0.1 to 10 THz. Many chemical agent explosives show characteristic spectral features in the terahertz. Compared with conventional methods of detecting a variety of threats, such as weapons and chemical agent, THz radiation is low frequency and non-ionizing, and does not give rise to safety concerns. The present paper summarizes the latest progress in the application of terahertz time domain spectroscopy (THz-TDS) to chemical agent explosives. A kind of device on laser radar detecting and real time spectrum measuring was designed which measures the laser spectrum on the bases of Fourier optics and optical signal processing. Wedge interferometer was used as the beam splitter to wipe off the background light and detect the laser and measure the spectrum. The result indicates that 10 ns laser radar pulse can be detected and many factors affecting experiments are also introduced. The combination of laser radar spectrum detecting, THz-TDS, modern pattern recognition and signal processing technology is the developing trend of remote detection for chemical agent explosives.
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