Terahertz Computed Tomography Imaging Based on an Improved Back-Projection Algorithm

A terahertz computed tomography (THz-CT) system was proposed in this paper. The system was built based on vector network analyzer, two-dimensional rotating platform and four terahertz lenses. The transmission coefficient of the sample at different projection angles was measured with the frequency of 0.39 THz. And then the two-dimensional image of the sample was reconstructed by the filtered back-projection algorithm. The results show that the system can recognize the internal structure of the object. We also compared the effects of different filter functions on image reconstruction results. This work has potential value for non-destructive inspection, medical field and related applications.