大口径标准镜绝对面形精度传递方法

Accuracy transfer method of large aperture standard mirrors' absolute surface error

提出了一种大口径干涉仪标准镜绝对面形精度的传递方法,在已知一台干涉仪参考镜绝对面形的前提下,可向待测标准镜进行精度传递。由于检测温度与使用温度的不同,待测标准镜在另一台干涉仪作参考镜时,绝对面形会发生变化,变化集中在离焦量上;在待测标准镜使用状态下,通过对经典三板互检法得到的竖直方向直线绝对面形的分析,得到标准镜使用状态离焦量的估计,以此修正直接精度传递结果,最终得到待测标准镜使用状态下的绝对面形。比较同一块光学元件在两台干涉仪上标定前和标定后的测量结果,标定后的面形差值更小且分布一致性更好,证明了本方法的有效性和可行性。

An accuracy transfer method of the standard flats＇ absolute surface error is proposed. When we acquire the abso lute surface error of a standard flat, we can use this method to transfer its accuracy to another standard fiat. According to the ex perimental results, we eonclude that Zernike polynomials＇ power term can fit the changing amount very well. In order to deal with the surface difference at different temperatures, we propose a method using the line＇s absolute surface data extracted by clas Meal three-flat test to estimate the power amount. A well manufacturing optical part is tested by two interferometers. The use of this method can lessen the difference between the results of two dimensional distribution.