Dispersion Compensation Technology Based On Terahertz Coherent Tomographic Imaging

Terahertz imaging technology is one of the terahertz technologies which are most widely researched, and due to its non-contact and non-destructive detection, terahertz imaging technology is widely applied in the field of pharmaceutical, medical, security, materials science, etc. Optical coherent tomography is one kind of imaging technologies which are developing rapidly in recent years, and it is based on the principles of optical interference and can obtain the high-precision cross-sectional imaging for the internal microstructure of the sample.By combining terahertz imaging technology with optical coherence tomography, a three-dimensional imaging technology- terahertz coherence tomography is discussed. And the corresponding dispersion compensation methods proposed are applied to the imaging technology. Compared with the existing terahertz imaging technologies, terahertz coherence tomography proposed achieved the high-precision three-dimensional reconstruction for the sample, and it has broad application prospects in the non-destructive detection, biomedical diagnosis, airport security, etc.The main content of the thesis includes:(1) By combining terahertz imaging technology with optical coherence tomography innovatively, a three-dimensional imaging technology- terahertz coherence tomography is discussed, the hardware of the system is built, the related codes to control the hardware and process the data of sample are programmed.(2) Numerical dispersion compensation method and hardware dispersion compensation method are introduced. And by theoretical analyses and numerical calculations, deconvolution algorithm and iterative compensation algorithm which both belong to numerical dispersion compensation method are elaborated in detail. Compared to deconvolution algorithm and hardware dispersion compensation method, it's not necessary for iterative compensation algorithm to know the dispersion characteristics and thickness of the sample in advance, so it has broad application prospects. Combined with three-dimensional imaging technique, the longitudinal resolution of the three-dimensional reconstructed image is about 100?m.