Shevchyk-Shekera A. Research and development of the terahertz vision system based on a multi-element radiation detector

The thesis describes the results of research and development of the THz vision system based on a multi-element radiation detector for non-destructive testing and visualization of the contents of letters and small boxes. The math model of thermal imaging systems had been taken and adapted for the THz vision system. The signal in all functional blocks of the THz vision system "Emitter – object – optical system – radiation receiver – signal processing unit – display –operator was reviewed. It is shown that for active THz vision systems, it is possible to manufacture diffraction aspheric quasi-optics using the technology of layer-by-layer fusion using a digital 3D model with an accuracy of 100 μm. The main stages of the technological process of manufacturing aspherical THz lenses with the help of a machine with numerical control were investigated. Recommendations of the machine operation modes are given to improve the cleanliness of the lens surfaces. The estimation of the main parameters of the developed by the THz radiation detector based on a CMOS transistor was given. It is shown that for 140 GHz the sensitivity and noise-equivalent power of such receivers is S=2,8×105 V/W, NEP=4,3×10-10 W/(Hz)-1/2. A model of a THz vision system based on a 40-cell CMOS transistor as a detector has been developed. This model can be used for further development of THz vision systems for non-destructive testing and visualization of the contents of letters and small wrappers. Images of various subjects at a frequency of 140 GHz, scan rates of 200 mm / s, scan time of 1 s were obtained.