Accurate infrared magnetic system (AIMS) is a ground-based solar telescope with the effective aperture of 1 m. The system has complex optical path and contains multiple aspherical mirrors. Since some mirrors are anisotropic in space, parallel light undergoes complex spatial reflection after passing through the optical pupil. It is also required that part of the optical axis coincides with the mechanical rotation axis. The system is difficult to align. This article proposes two innovative alignment methods. First, a modularized alignment method is presented. Each module is individually assembled with optical reference reserved. System integration can be completed through optical reference of each module. Second, computer-aided alignment technology is adopted to achieve perfect wavefront. By perturbing the secondary mirror (M2), the influence of M2 position on the wavefront is measured and the mathematical relationship is obtained. Based on the measured wavefront data, the least squares method is used to calculate the M2 alignment and multiple adjustments have been made to M2. The final system wavefront has reached RMS=0.12 λ@632.8 nm. Through observations of stars and sunspots, it has been demonstrated that the optical system has good wavefront quality. The observed sunspot is clear with the penumbral and umbra discernible. The proposed method has been verified and provides an effective alignment solution for complex off-axis telescope with large aperture.

中文翻译：

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1米级高精度红外磁系望远镜光学对准技术

精确红外磁系统（AIMS）是有效孔径为1 m的地基太阳望远镜。该系统光路复杂，包含多个非球面镜。由于有些镜子在空间上具有各向异性，平行光通过光瞳后会发生复杂的空间反射。还要求部分光轴与机械旋转轴重合。该系统很难对齐。本文提出了两种创新的对齐方法。首先，提出了一种模块化的对齐方法。每个模块均单独组装，并保留光学参考。通过各模块的光学参考即可完成系统集成。其次，采用计算机辅助对准技术，实现完美的波前。通过扰动次镜（M2），测量M2位置对波前的影响，并得到数学关系。根据测量的波前数据，采用最小二乘法计算M2对准，并对M2进行多次调整。最终系统波前达到RMS=0.12 λ@632.8 nm。通过对恒星和太阳黑子的观测，证明该光学系统具有良好的波前质量。观测到的太阳黑子清晰，半影和本影清晰可辨。该方法经过验证，为复杂大口径离轴望远镜提供了有效的对准解决方案。