Alignment algorithm of nonsymmetric off-axis reflective astronomical telescopes based on the modified third-order nodal aberration theory

• DOI: 10.1364/oe.453005
• Publication Date: 2022-03-28T07:30:06Z
• Authors: Jinxin Wang; Xu He; Jing Luo; Xiaohui Zhang; Tianxiao Xu
• Keywords: Coma (optics); Exit pupil; Optical aberration

For pupil-offset off-axis reflective astronomical telescopes with designed tilts and decenters, owing to the absence of symmetry, axial lateral misalignments exhibit strong coupling. The astigmatic coma aberration fields misaligned optical systems are not only effected by but also closely related misalignments. However, traditional misalignment algorithm based on nodal theory (NAT) usually ignore effect when constructing calculation models. As a result, presence in decenters will invalidate NAT-based algorithm, which makes it difficult be applied actual computer-aided alignment experiments. In order solve this issue, framework modified NAT, third-order astigmatic, coma, spherical net induced separated from total fields, their inherent relations analytically expressed. On basis, construct solution model that can simultaneously quantitatively calculate misalignments, method is proposed fit partial derivative coefficient matrix according field dependence aberrations simulation experiments were performed real wide-field three-mirror telescope using constructed model, proved feasibility method. Simulation show for different conditions generated randomly, both have achieved convergent results. experiment, average RMS wavefront errors nine views corrected 1.9 λ 0.12 (λ = 632.8nm) through 3-5 iterations.