Terahertz (THz) radiation is low in energy and, therefore, not harmful to health. It penetrates paper, clothing, most plastics, polystyrene foams and semiconductors. However, it is strongly absorbed by water and reflected by metals. Many molecules e.g. organic substances, pharmaceutical products, illicit drugs and explosives can be detected and identified using THz radiation.
Time-resolved measurements with ultrashort THz pulses combined with broadband spectroscopy enable a wide variety of applications in the fields of non-destructive testing, security and tomography. For example, it is possible to determine the thickness of the layer or delamination of optically opaque materials as well as inspect plastics for inhomogeneities and inclusions. Moreover, the inner content of the sample can be localized and identified.
Fig. 3 shows the time-resolved measurement of the electrical field strength of an ultra-short THz pulse. The amplitude and time-delay of the THz pulses is used for imaging and tomography; the spectral characteristics and parameters of the sample can be calculated by means of the Fourier transform.
- Design, development and realization of customized THz systems
- Research on the applicability of THz radiation
- Imaging, tomographic and spectroscopic measurements in transmission and reflection
- Homogeneity examination, characterization of layer structures
- Comparison of CAD and measurement data