Design of apochromatic telescopic optical system based on PWC method

Abstract

According to technical requirements,an apochromatic telescopic optical system which is characterized by the focal length 1.5m~2m,with the visible region spectrum band is needed.The successful design consists in using normal glasses based on PWC method to get a completely secondary-spectrum-removed and cramped construction telescopic optical system in this paper.Firstly, by the aberration theory and ZEMAX optical design software,a catadioptric achromatic optical system composed of a reflecting mirror and a couple of air-spaced negative doublets are designed.The initial configuration of optical system is calculated by PWC method and the proper couple of air-spaced negative doublets are chosen by the theory of achromatic.By comparing with various optical systems with different couple of air-spaced negative doublets, it is found that the combination of the heavy crown glass ZK7 and heavy flint glass ZF3 is effective to correct chromatic aberration and its secondary spectrum value is minimality.It can conclude that fact with the abbe number of ZK7 is twice than ZF3 make the good result and give guiding to the design of the same type of optical system. Secondary,according to the theory of secondary spectrum,the secondary spectrum value to be corrected is analyzed and the compensation can be changed by adjust the magnification power.The comparison is presented and the final telescopic optical system with cramped construction is achieved, and the goal of apochromatism and other aberration is reached.