The Telephoto Design Based On Binary Optics

Binary optical elements have been shown to be very popular in a wide variety of application for its features such as the effects of wavefront complex amplitude modulation which can effectively improve the structure and property of the traditional refractive type optical system.In this paper,a telephoto objective is designed under the general requirements of joint transform correlator(JTC),With program ZEMAX,the initial telephoto objective which is made of five pieces of lenses is designed with normal spherical surface,then on the basis of the original spherical structure,an aspheric surface is introduced, optical system can be reduced into four pieces of lenses,its modulation transfer function(MTF) is near to diffraction limit,The RMS radius of each field of view are 7.704μm,8.347μm,8.974μm and the diameter of airy disc is 7.209μm,the RMS radius is approximate to airy disc.the wavefront aberration is larger than 1/4λ,the wavefront aberration is less than 1/4λ.In order to improve the structure and performance of the optical system,an improved project is put forward,and binary optics technology is introduced,optical system can reduce into four pieces of lenses,its modulation transfer function(MTF) is approached to diffraction limit,The RMS radius of each field of view are 4.999μm, 5.393μm,5.863μm and the diameter of airy disc is 7.261μm,the RMS radius is less than the diameter of airy disc.the wavefront aberration of three fields of view are all less than 0.15λ,the chromatic aberration has been corrected in two positions,and the secondary spectrum has also been corrected.The telephoto can detect the farther target in real time,recognize it automatically and locate it accurately.