Free-form surface space optical system

We made a brief summary of the development and application of free-form surface,introduced the research status of free-form surface in space optical system abroad,described the characteristics of three kinds of free surface mathematical models and the aberration balancing ability,focused on the aberration characteristics of free-form surface optical system compared with the axisymmetric system and plane-symmetric system.In addition,we presented the aberration controlling and evaluation method of the free-form space optical system.Finally,we gave the design results of the free-form surface multi-spectral camera adopting Zernike polynomial representations.The results show that the imaging field of view is 76°,it adopts telecentric optical path design;the wide field of view MTF is superior to 0.56,and it is applicable for space multispectral imaging.