针对凸非球面大口径、大相对孔径、全口径检验难的问题,提出了一种利用自准校正单透镜检验凸非球面的方法。该方法通过在单透镜的凸面镀半反半透膜构成自准校正透镜,校正非球面的球差,从而实现大口径凸非球面的全口径检验。依据三级像差理论,推导了初始结构参数计算公式,介绍了检验光学系统的设计方法;对口径为240.62 mm、相对孔径为0.48的凸扁球面光学检验系统进行了模拟设计。系统优化后的残余波像差峰谷(PV)值为0.00025λ,均方根(RMS)值为0.0001λ(λ=632.8 nm)。将该方法用于工程项目中口径为287 mm、相对孔径为0.74的凸双曲面反射镜检验中,测得镜面RMS为0.021λ,验证了该方法的可行性。最后对该方法的适用性以及像差校正能力进行分析。研究结果表明:该方法可以实现任意偏心率凸非球面的全口径检验,在大口径、大相对孔径凸非球面全口径检验时具有较大优势。

Testing the full-aperture of convex aspheric surface with large aperture and large relative aperture is challenging. To solve this problem, we propose a convex aspheric surface testing method using an autocollimation lens in this study. In the proposed method, a self-aligning lens is formed by plating a semi-inverted semi-permeable film onto the convex surface of a single lens to correct the spherical aberration of the aspheric surface, enabling the full-aperture testing of the large-aperture convex aspheric surface. We derive initial structure parameters using the third-order aberration theory, and then introduce the design method in detail. We design and simulate an optical system to test a convex oblate spheroid with an aperture of 240.62 mm and relative aperture of 0.48, and then perform a tolerance analysis of the system. The peak valley (PV) value of the residual aberration of the optimized system is 0.00025λ and the root-mean-square (RMS) error is 0.0001λ. The proposed method is also applied in testing a practical convex hyperboloid with an aperture of 287 mm and relative aperture of 0.74. We obtain an RMS of 0.021λ, which verifies the feasibility of the proposed method. Finally, the applicability of this method and the aberration correction ability are analyzed. In summary, the proposed method can be used to test the full-aperture of any eccentricity convex aspheric surface, and it has great advantages in testing full-aperture of convex aspheric surface with large aperture and large relative aperture.