Design and Optimization of Gregorian-based Reflector Systems for THz Imaging System Optics

The application of reflector antenna configurations in designing the optical section of terahertz imaging systems has attracted great attention in recent years. The advantages of reflective optics in comparison with refractive optics is one of the main reasons for this trend. Specular reflection in a broad spectral range, no or little reflection and transmission loss, no chromatic aberration, and high reliability in high power applications configuration are just some of these advantages. In this paper, the optical performance of a modified off-axis aberrations-free Gregorian-based reflector antenna system is studied as an optical section of a terahertz imaging system. By applying a precise optimization procedure, the optical and imaging performance of the reflective structure is optimized with respect to the proposed optimization goals. Furthermore, it will be shown that although the apparent complexity of the overall configuration, by carefully utilizing the optical techniques, a near-ideal focusing optics is achievable.