THz imaging with spectral resolution for identification of traces of explosives

The presence of characteristic peaks in the terahertz (THz) absorption spectra of many organic substances and the active development of the technology for manufacturing video cameras based on microbolometric matrices create an increased interest in methods for identifying explosive compounds using THz imaging with simultaneous recording of spectral information. The results of relevant studies can be used in the development of security systems. THz images (taking into account the spectral information in each pixel) were obtained in this work by passing radiation through a sample based on hexogen (RDX) microcrystals deposited on a polyethylene (PE) film. A photoconductive antenna was used as a source of broadband radiation in the range from 0.5 THz to 2.5 THz. Spectral resolution was provided using a Fourier spectrometer based on a Michelson interferometer. The images were recorded using a THz video camera based on a microbolometric matrix. The possibility of identifying RDX microcrystals using color visualization of spectral information in the frequency range of one of the characteristic RDX peaks (~0.8 THz) has been demonstrated.