Terahertz band covers a spectral region from 0.3 to 10 THz (10-300 cm-1). Terahertz technology includes such components as sources of terahertz frequency radiation, the manipulation of the radiation, and its detection. Terahertz spectrometer is a source operating in the time-domain arrangement (THz-TDS). Simultaneously, the THz-TDS setup ensures an effective detection of terahertz wave. The setup bases on two semiconductor LT-GaAs chips operating as a THz source and detector as well. A femtosecond laser is applied as an exciting and sampling device. The terahertz wave is carried by parabolic off-axis mirrors. In the numerical part, the signal is processed to obtain basic data as an absorption coefficient and refractive index of the medium under investigations.
Terahertz technique mainly focuses their interest on biomedicine, food and pharmaceutical industry, and public and military security.