THz Transmittance and Reflectance Spectroscopy on Security-relevant Materials using Synchrotron Radiation

Many attempts have been made to introduce THz detection systems for security inspection at check points. For all approaches the spectral characteristics of the most common materials of investigation are required both in reflectance and transmittance. We investigated a broad variety of materials, including explosives, polymers and drugs by using Fourier-Transform Spectroscopy and synchrotron radiation as a broadband THz source. The spectral properties are discussed with respect to the material density, thickness, grain size, and measurement geometry. We found strong dependence on the aforementioned parameters which have to be considered for time-domain and other laser-based detection systems.