一种大口径大非球面度天文镜面磨制新技术  

A New Polishing Technology For Large Diameter and Deep Aspherical Mirror

作　　者：崔向群[1] 高必烈[1] 汪达兴[1] 朱永田[1] 杨世海[1] 朱政[1] 王磊[1] 夏自立[1] 

机构地区：[1]中国科学院国家天文台南京天文光学技术研究所,南京210042

出　　处：《光学学报》2005年第3期402-407,共6页Acta Optica Sinica

基　　金：国家自然科学基金(19633020)资助课题

摘　　要：主动抛光盘技术是近年来因天文望远镜的口径越来越大,焦比越来越快而发展起来的一种能够根据需要将抛光盘面实时地主动变形成偏轴非球面来磨制大口径非球面度高精度天文镜面的磨制技术。非球面表面的曲率不仅各点不一致,而且同一点的径向与切向曲率也不相同,所以经典的大的抛光盘不可能使其表面形状始终与所接触的非球面表面形状相吻合;常用的小磨盘抛光的致命缺点是解决不了高频切带,抛光效率也低。而主动抛光盘技术正好解决这些难题。与传统方法相比,它具有较高的磨削速率和较大范围内的自然平滑(无切带)。这是一种用计算机控制的磨镜技术,通过它可以像加工球面一样来加工一个深度的非球面。介绍了我国成功研制的主动抛光盘以及它在直径910 mm,焦比F/2抛物面镜加工中的成功应用和加工的结果,以及此项技术将在2 m以上直径天文镜面,特别是30 m巨型天文光学/红外望远镜的分块子镜磨制中的应用前景。Stressed lap polishing technology is a new large and deep asphericity astronomical polishing mirror. Because the diameter of astronomical mirror is larger and larger, the asphericity is deeper and deeper, we develop the stress lap technology, it can actively deform the lap surface to become an off-axis asphere according to different lap position on mirror surface and different angle of lap. The curvature is different not only on different position, but also on different direction, so the classical large polishing lap cannot keep the lap surface with the aspherical mirror surface when it moves and spins on the mirror surface. The classical small polishing tool not only can get high frequency error on the mirror surface, but also has slow polishing speed. The stressed lap is just enough to solve these problems. Compared with traditional polishing methods, it has high polishing speed and natural smooth. It is computer-controlled polishing technology, using it the authors can polish a deep aspherical mirror just like polish a spherical mirror. This paper introduce our stressed lap and how to apply it to 910 mm, with F/2 paraboloidal mirror and its testing result. Next step, the authors will develop this technology to polish the off-axis aspherical segment.

关 键 词：天文光学 天文镜面技术 主动抛光盘 非球面镜 

分 类 号：O43[机械工程—光学工程]