Spectral identification of nitro compounds using a terahertz source based on an impact ionization avalanche transit-time diode

The terahertz (THz) transmission spectra of nitro-compound layers were studied using a THz source based on an impact ionization avalanche transit-time (IMPATT) diode, as well as a photoconductive antenna. The THz spectra were recorded with a Fourier spectrometer based on a Michelson interferometer. A THz video camera with a microbolometer matrix was used as a THz radiation detector. The possibility of spectral identification of nitro compounds by using a THz source based on an IMPATT diode was experimentally demonstrated due to the presence of intense characteristic absorption bands of these substances in the range of its harmonics (0.58–1.45 THz).