Research And Application Of Terahertz Time-domain Spectroscopy Systems Based On GaAs Photoconductive Antenna

Terahertz time-domain spectroscopy(THz-TDS)is a powerful tool to investigate spectroscopic properties of matter at THz frequencies.The invention of THz-TDS fills up the"THz Gap" in spectroscopy.With the development of THz-TDS,studies of substance characteristics have spread into various of fields,such as biology,chemistry,medicine,and security,So the reaslistic applications of THz-TDS technology have become one of the main development trends.The main achievements of this work are listed in the following:(1)We put up a THz-TDS system based on PC antenna emission and ED detection,and illustrate the difficulties and focus in the debugging process.(2)The quality factors occurred during the generation transmission and detection parts of THZ-TDS have been analyzed.Factors,that impact the system properties,such as antenna parameter set,antenna declination,polarization detection characteristics of electro-optic crystal ZnTe,and the bias dealy-line,are analyzed and experimentally stuied,and hereby the spectroscopy syetem is optimized.(3)We explore the propagation characteristics of THz,electromagnetic waves in plasma based on THz-TDS.