Design Of Mid-Infrared Zoom Optical System With High Ratio

The application of infrared zoom optical system is increasingly widespread in the field of military and civilian detection and recognition, with the characteristics of the infrared system that can all-weather work and anti-interference ability and the function of the zoom system that can search and indentify the targets. Therefore, according to the infrared technology and zoom theory, research infrared zoom optical system with high performance has important practical significance.First, the basic principle of zoom optical system was analyzed, and the narcissus phenomenon of refrigeration optical systems and the athermalization theory were introduced. Second on the basis of640×512cooled staring focal plane array (FPA) detector, a mid-infrared zoom optical system with the high-magnification ratio of30was designed. The F number of this zoom optical system was3.7, the work waveband was3.7～4.8μm, the focal length ranged from11.64to349.2mm, and the field of view ranged from1.05×0.84°to28.8×23.74°. Considering various factors of the transmission links, the spatial resolution of the systems could be achieved211p/mm. The re-imaging optical configuration could get approximately100%cold shielding. Finally, the narcissus was analyzed, and the system had achieved the passive optical athermalization design in the range of-40℃～+60℃。...