Optical System Design Of Infrared Imaging

In recent years, with the rapid development of science and technology, especially the advance of infrared detector technology, the emergence of new material and increasing improvement of production technology, infrared imaging system is increasingly used in military and civilian areas. Infrared optical system is an important part of infrared imaging system. It is used for collection of infrared radiation from object and background. And the infrared radiation is converged in photosensitive surface of infrared detector in order to develop image of object and background. With continuously upgrade of infrared detector and increasing requirement of infrared detection system by various applications, higher requirement for the performance and optimum design of infrared optical system is also put forward. Under such circumstances, the study of infrared imaging optical system design is undoubtedly significant.In this paper, the basic theory of engineering optics and design methods of optical system design are described. Optical character and the relation between imaging quality and system structural parameter are analyzed, and then how to reduce system aberration is discussed. According to the characteristic and design principle of infrared imaging system, the selection principle of infrared optical material is discussed and its process technology is introduced. Infrared materials to the machinability and economic options to infrared material is also taken into account. The system type of infrared imaging system is chosen as dual-mirror system, and the object lens design formula of infrared imaging dual-mirror system is derived. When the distance between focus and main mirror required by the infrared device and system focal length are determined, the non-spherical type of primary mirror and vice mirror of double-mirror system is determined according to the requirement of eliminating aberration of infrared imaging. The reliability of derived formula is verified by calculation of examples and simulation is made through optical design software Zemax. The 3D Layout plan of optical system is given, namely the composite error of optical system. At the same time, Transfer Function map of different field, the center brightness map and point map of system are also given by Zemax software. These maps indicate that image quality is good when the primary mirror and vice-mirror of double-mirror system are hyperboloidal. The requirement of infrared imaging system is satisfied and the expected objects are achieved, fully meeting the design requirements.