A Dual-band Common-aperture Continuous-co-zoom Optical System Design

A dual-band common-aperture continuous-co-zoom optical system for visible and MWIR can improve the probability of recognition of omnibearing and multilevel of targets information for optoelectronic devices,multi-band and optical-imaging system has a good complementary in target recognition,MWIR-visible multi band optical system can be used for high resolution imaging under the good visibility in the daytime,or radiation detection under the poor visibility in the night.By combining the continuous zoom system with MWIR-visible dual band system to make the targets imaged,a dual-band common-aperture continuous-co-zoom optical system is set up,the system can switch instantly and real-time for different wave bands which can avoid the disadvantages of time consuming in traditional multi-band system and improve the performance of system and the ability for capturing the multilevel targets.By deducting the theory of the dual band zooming and confocal of MWIR-visible band,A visible-MWIR dual-band common-aperture optical system is designed,the zoom range is 21.5mm to 171.5mm and the zoom ratio is 8.In order to compensate focal length difference between the dual bands,the focal length difference in the dual-band continuous-co-zoom optical system and difference of zoom ratio is analysed,According to the results of difference analysis,deducting the function of dual-band confocal and achromatic triplet,using this two function,a dual-band confocal ideal system is set up,aberration in the system is analysed,using the ability of correcting the aberration of different shapes of lens in the same optical power to design the ideal lens elements seperately,the focal length difference between visible and MWIR lights is smaller than the depth of focus of the system when designed common-aperture continuous-co-zoom optical system in any zoom position,by ray tracing reversly,accomplish the narcissus analysis and depression of the infrared optical system.athermalization is made in-40-60?,the results show that the MTF is above 0.6 at 801p/mm in visible light and above 0.5 at 201p/mm in MWIR which satisfied the design requirement...