大口径碳化硅材料凸非球面反射镜的检验

Testing methods for large aperture convex SiC asphere mirror

为了实现某大口径碳化硅材料凸非球面反射镜检验,研究了无像差点法以及补偿检验法方案。经过比较优选,确定选用补偿检验方案并专门设计了高精度大口径非球面补偿器,设计精度为PV:0.0082λ,RMS:0.0029λ(λ=632.8nm)。采用会聚光束,使用大口径数字干涉仪进行凸非球面正面检测,最终检测结果为0.022λ(RMS)。所述补偿器的设计方法和要求具有普遍性,设计结果也可用于同类型大口径凸非球面检验用补偿器的设计。采用该方法提高了凸非球面检测精度,并且在凸非球面镜的材料选择、结构设计、支撑方式等方面提供了更多的优化空间,为新型光学材料在凸非球面反射镜的应用奠定了基础。

In order to test a large aperture SiC convex asphere, the anastigmatic null testing methods and null lens compensator testing method are analyzed. After comparison, the null lens compensator testing method is selected to use in testing the asphere mirror and a null lens compensator for large SiC convex asphere is designed. The design results indicate that the precision of the system is PV. 0. 008 2λ,RMS.0. 002 9λ（λ=632.8 nm）. A large aperture Zygo interferometer is used in testing the large aperture mirror,the final testing results is 0. 022 λ（RMS）. Proposed design method is universal and the design results can be used in the compensator design for other convex SiC mirrors. Testing result shows that the convex asphere has been improved, and the selection aspects of material, design structure and support structure in this paper can give a lots references for new style of convex asphere mirror.