Ф750mm口径望远镜光学系统的检测(英文)

Optical Measurement of Ф750mm Telescope System

为了探测更高轨道的空间目标,研制了一台通光口径为Ф750mm的望远镜.该望远镜为主焦点光学系统,由一片二次非球面反射元件和四片透射元件组成,具有大视场(4°),大相对孔径(1∶1.32)和宽光谱(500～800nm)的特点.本文以该望远镜的研制为基础,介绍了其光学系统各个元件的单独检测和系统装调完成后的整体检测方法和过程.采用样板法对系统中的球面透射元件进行了单独检测,采用透射无像差补偿器法对二次非球面反射镜进行了单独检测,采用反射无像差补偿器法对组合起来的透射校正镜组进行了检测,并且对系统装调对准之后的光学系统进行室内平行光管和室外对星观测两种方法进行检测.测量结果均满足设计要求,其中球面透镜的面形误差小于0.1个光圈,反射元件和透射元件非球面表面的面形误差均优于λ/30(λ=632.8nm),透射校正镜组的波像差优于λ/30(λ=632.8nm).光学系统整体检测结果表明,室内和室外检测结果一致,其像面的80%能量集中度直径在4°的全视场范围内均小于2个像元,达到了设计的成像要求.

For detecting space debris in the high orbit,a telescope with wide field of view (4°),large relative aperture (1 ∶ 1.32) and broad wavelength (500 nm to 800 nm) is obtained.The telescope,whose clear aperture is φ750 mm,consists of primary mirror and refractive corrector group.The surface type of primary mirror is parabolic,and the refractive corrector group includes one ellipsoid lens and three spherical lenses.The advanced methods of optical elements measurement and whole system are introduced respectively.Firstly,the figure error of spherical lens is measured using template method.A compensation test method of null lens is used to test the hyperbolic primary mirror and ellipsoid corrector lens.Next,when the corrector lens group is aligned,the whole corrector lens group is tested making use of a new spherical mirror method.And at last,it is adopted to measure the optical telescope with collimator test in the room and with nature star observation outdoors. All of the measurement results are satisfying the requirement of design.The figure errors of spherical lenses are less than 0.1 fringe in the first step,the figure errors of primary mirror and ellipsoid lens are less than λ/30 (RMS),and the wavefront error at the third step is less than λ/30 (RMS).After measuring the whole telescope optical system in the room,the 80％ encircled energy is within 2 pixels,at the side of that,when observing the stars outdoors,the 80％ encircled energy is also within 2 pixels in the whole field of view,4° diagonal.