Ф1300mm非球面反射镜的加工与检测

Fabricating and testing of Ф1300mm aspheric mirror

介绍一块Ф1300mmULE材料非球面反射镜的加工与检测方法。采用非球面超声铣磨、机器人研抛等多个工序组合加工技术完成了非球面反射镜的加工。在非球面检测中,采用大口径三坐标测量的方法进行了研磨阶段的面形检测,通过Z向滤波的方法对面形拟合过程中的噪点误差进行了处理,将研磨阶段的面形精度提高至5μm PV值。在干涉仪测量阶段,采用气囊支撑方法对反射镜的重力误差进行了卸载,通过非线性误差矫正的方法去除了零位补偿检测所带来的非线性误差,反射镜的最终精度达到0.016λRMS。试验结果表明,大口径非球面反射镜各项技术指标均满足设计要求,所用工艺方法适用于加工更大口径的非球面反射镜及其他类型的大口径非球面光学元件。

The manufacturing and testing ofΦ1300 mmULE aspheric mirror is introduced.In the process stage,ultrasonic milling and robot polishing are used to finish the fabrication of the aspheric mirror.In the grinding test stage,the surface figure error of ashperic is firstly controlled by using the coordinate measuring machine（CMM）and then Z axis filtering method is used to eliminate noise error in the surface fitting,the grinding accuracy finally achieve 5 micron PV.In the interferometer test stage,the airbag zero gravity uploading method is taken to upload the gravity error of aspheric mirror,while the nonlinearity error caused by null compensation is removed by the method of nonlinear error correction,and the final manufacturing precision is 0.016λRMS.The results show that all technical indicators of large aspheric mirrors meet the design requirements,this process can be applied to machining larger caliber aspheric mirrors and other types of large aspheric optical element.