Design of Off-axial TMA Infrared Optical System for Space Camera

The developing trend and characteristics of the space optical system are long focal length,large view field,light weight,small dimension,large relative aperture and high image quality.A method of designing off-axial three-mirror anastigmat(TMA) infrared optical system is presented,through analyzing the design model and parameters of aspheric reflective optical system,based on coaxial three-reflective optical system.The structural parameters of the system can be solved and optimized by ZEMAX.Then the off-axial three-mirror system with focal length of 1000 mm,field of view of 4 and relative aperture of 1/4 is designed.After optimization,the modulation transform function(MTF) of field of view is 0.3 at 50 lp/mm,and the full field diffusion plaque is controlled into 10 m.This system overcomes the central shielding problem which exists in coaxial TMA system.So the image quality of the system is greatly improved.