Optical System Design Of Uncooled Infrared Zoom Lens

In recent years, infrared zoom system in terms of structure or performance has been improved greatly with the increase of infrared material types and improvement of processing technology. Then a great number of infrared zoom systems appear in military field. Optical system in this thesis is applied to the detection and identification of tank target, it is used with a combination of joint transform correlator. The infrared zoom system is an important part of tank image capturing system, target can be searched in short focus, and it can be observed in long focus by using the optical system. This system can be working day and night.In this thesis, the research of infrared zoom system in internal and external is reviewed, theory of joint transform correlator is discussed, and the Gaussian solve of zoom system is detailed analyzed. Then an infrared zoom optical system working at8μm～12μm waveband is designed according to the practice requirements. This system can zoom continuously in the range of20mm-300mm, its F number is3.The system contained seven lenses with one aspheric surface.MTF curve in each focus is higher than0.5when the maximum cut-off frequency is lllp/mm. The system is compact and its total length is330mm.Lastly, tolerance analysis is carried out in order to ensure the feasibility. Image quality changes in a permitted range of practical applications according to the tolerance confine, the target can be well detected and recognized in the battle field.