将光学系统波像差检验技术与子孔径拼接测试技术相融合提出了凸非球面系统拼接检测方法,对该方法的原理和实现步骤进行了分析和研究,并建立了合理的子孔径拼接数学模型.依次利用计算机控制光学表面成形技术和磁流变抛光技术对一包含大口径凸非球面的离轴三反光学系统的各反射镜进行加工,并对整个系统进行装调和测试.测定光学系统各视场的波像差分布,通过综合优化子孔径拼接算法和全口径面形数据插值求解得到大口径凸非球面全口径的面形信息.结合工程实例,对一口径为292mm×183 mm的离轴非球面次镜进行了系统拼接测试和加工,其最终面形分布的均方根值为0.017λ(λ=632.8nm).
The testing method combining systemic wave aberration testing with subaperture stitching interferometry was proposed for measuring large off-axis convex aspheric mirror. The basic principle and process of the technology were analyzed and researched, and the stitching mathematical model was established. When the large convex surface is polished very well and the primary mirror and tertiary mirror of the optical system are fabricated by computer controlled optical surfacing and magneto rheological finishing, the three mirror astigmatism system can be aligned and adjusted. The wave aberration of each field can be tested by aligning and calibrating the optical system successively, and the phase map of the whole aperture can be calculated by the synthetical optimization stitching algorithm and interpolation. With engineering examples, a three mirror astigmatism optical system with a large convex aspheric mirror with the aperture of 292 mm×183 mm was fabricated and tested by the method. At last, the root mean square of the surface error is 0.017λ(λ=632.8 nm).