Optical effects at projection measurements for Terahertz tomography

Optical aberrations like refraction, diffraction and edge effects have an influence on Terahertz measurements. They can produce image artifacts which make it difficult to detect and resolve material defects inside the samples. We used a geometrical optical ray tracing approach to analyze the optical effects at Terahertz projection measurements which can be used to perform 2D or 3D THz images. We measured plastic samples with different shapes and compared them to simulations which are realized with the software ZEMAX. Furthermore, different methods to overcome the impact of edge effects will be introduced.