Design of optical system for Fizeau-type synthetic aperture telescope

An optical system for Fizeau-type synthetic aperture telescopes is designed by using three subapertures with small diameters to obtain the high resolution of an equivalent large aperture.First,considering both u-v covering of sparse frequency and structure simpleness,the Golay-3 array is choosen to be the subaperture arrangement and the filling factor F is 0.44.Then,according to the character of optical system configuration,the optical system is divided into the subapertures,ray controller and the ray combiner to be designed,respectively.The configuration of afocal subaperture is Cassegrain type with achromatic double lenses rearward,and its pupil diameter,Field of View(FOV) and angle magnification are 300 mm,0.2° and 10,respectively.Moreover,the ray combiner is composed of 5 pieces of glass including high refractive index glass and special partial dispersion glass,and its focal length is 600 mm,F-number and FOV are 6 and 2.The Point Spread Function(PSF) and Modulation Transfer Function(MTF) of the subaperture are analysed,and the results show that the equivalent diameter of total system is 1.89 times that of the subaperture,and the angular resolution of total system is 0.24″.