THz-TDS With Photoconductive Antennas And THz Wavelet Domain Spectroscopy

THz science is a new research field, which is quite valuable to the science development and human society in future. As one of the most widely used THz technique, THz time-domain spectroscopy(THz-TDS) is playing a more and more important role in many research fields due to its particular advantages such as broadband detection, high signal-to-noise ratio, high time resolution and phase coherent detection. The first part of the dissertation is the research on THz-TDS system based on antennas. The THz signal from the emission antenna is presented. In the second part, continue wavelet transform(CWT) is used to analyze a chirped THz pulse. The main works in detail are classified as follows:1. THz science and technology is reviewed, including its history, emission, detection, application, advantages and some recent researches.2. The structure of the THz-TDS system based on PC antenna is introduced. And the module of antenna is described particularly, including each component in the module and the method of mounting them. Both of the experiment process and the signal from the emission antenna are presented. Theory of the system is analyzed in detail, respectively, including the emission antenna, the detector antenna and the optical system3. The background of wavelet transform is reviewed. A THz pulsed through a metal cylinder waveguide is analyzed by using CWT. And there is a comparison between wavelet transform and Fourier transform. At last, the impact of the shape factor on wavelet transform is discussed in detail.