Design And Development Of Unobscured Two-mirror Fore-optical Telescopic Objective With Wide Field Of View And High Speed

Recent years，with the emerge of high resolution imaging spectrometer，two-mirroroptical system has become a hot hit of research with its extremely simple structure andachromatism. This thesis explores the possibility for the two-mirror system to be the foreobjective of imaging spectrometer with wide coverage，broad band，high resolution andhigh SNR through its detail aberration analysis，optimal design and trail-production. This isa preparation for further development of the imaging spectrometer.First，the structure characteristics and working principle of unobscured two-mirrortelescope consisting of one convex and one concave mirror are introduced. The vertexcurvature radius of the convex mirror is used as an independent variable in analyzing therelationship between its structural parameters. Its astigmatic feature is analyzed withYoung’s formulas and anastigmatic condition is derived and the value interval of the vertexcurvature radius of the convex mirror is presented. An athermal design is realized with thewhole-aluminum-alloy structure. Based on Gaussian optics and third order aberrationanalysis，a two-mirror telescopic objective with biased field of view and imagerytelecentric and flat-field is optimally designed. Its working wavelength ranges from visiblelight to near infrared，and its F number and its full field of view is respectively up to2and40degrees. Its performance evaluation and remaining aberration analysis are given. Then，the stray light characteristics of the designed system and its baffles structure designed areanalyzed and presented with geometric calculation and non-sequential ray tracing. On thebase of its error analysis，tolerances are optimized and allocated. Finally，the processingmethod of aspheric mirrors with single point diamond turning is introduced andtrial-manufacture of the lens is reported，including the processing and testing of aspheric mirrors，optomechanical design，assembly and alignment，etc. The test results show that theperformance of the lens has reached the design requirements. The developed unobscuredtwo-mirror fore-optical telescopic objective with wide field of view and high speed hasmany advantages of simple and compact construction，low manufacturing cost and shortdevelopment cycle.