Considering the importance of explosives detection in the field of security and the increasing atmospheric pollution, the research on Fourier-transform near infrared Raman spectroscopy (FT-NIR) and terahertz time-domain spectroscopy(THz-TDS) of explosives has been developed preliminarily.

An overview of our studies of several effects in THz time domain spectroscopy and of the properties of THz microstructured devices is presented.

On the one hand,several important effects that are important for THz time domain spectroscopy are discussed: two-photon absorption,diffraction effect,and nonlinear effects(Kerr effect and Kerr-like effect) that affect the efficiently of the THz emitter;carrier-envelope phase offset of THz wave;and THz wavelet transform technique.

By employing the semiempirical dispersion formula for coplanar transmission lines, the mode dispersion and Cerenkov radiative attenuation characteristics in the frequency domain over a terahertz range of coplanar striplines on thick LT GaAs substrate were analyzed.

In the experiment for studying the nature of coupling between suface plasmon(SP) wave and terahertz radiation by subwavelenth-sized brass rods,we found that the polarization of the THz field,size of rods,and slit between rods critically affect the coupling efficiency.