Fraunhofer Institute for Industrial Mathematics ITWMWith the use of terahertz spectroscopy, chemical substances can be detected and identified. Thanks to the high degree of selectivity, pure substances or mixtures, as for example pharmaceuticals, drugs or explosives, can be detected specifically. This works almost without loss, even through paper or plastic packaging. In contrast to IR and Raman spectroscopy, which are sensitive to intramolecular vibration and rotation movements, terahertz spectroscopy gives information about intermolecular movements. Besides the proof of macromolecules, further information about the physical state, polymorphic structures as well as crystalline structures of the substances can be obtained. Terahertz technology is increasingly applied in addition to X-ray diffraction, since it is faster, needs less sample preparation, and is suitable for online-inspection.
We developed a spectrometer, that detects the chemical fingerprint of substances (gases, liquids, solids). The system is based on terahertz time domain spectroscopy. Measurement is possible in transmission as well as in reflection. For the analysis of powders and liquids an ATR (Attenuated Total Reflexion) assembly can be applied. Measurement data is evaluated automatically by means of chemometry. Terahertz spectrometer can also be used for the detection of moisture distribution and for the identification of the doping of semiconductors.