[1] T Yang, J Zhu, G Jin. Starting configuration design method of freeform imaging and afocal systems with a real exit pupil. Applied Optics, 55, 345-353(2016).

[2] [2] Cook L G. Fast folded wide angle large reflective unobscured system: US, US5331470[P]. 19940719.

[3] H Ji, Z Zhu, H Tan, et al. Design of a high-throughput telescope based on scanning an off-axis three-mirror anastigmat system. Applied Optics, 60, 2817-2823(2021).

[4] J Zhu, W Hou, X Zhang, et al. Design of a low F-number freeform off-axis three-mirror system with rectangular field-of-view. Journal of Optics, 17, 15605-15608(2015).

[5] [5] Cook L G. Wide field of view focal threemirr anastigmat: US, 5170284(A)[P]. 19921208.

[6] D Zhu, Y Zhang, Z Hu, et al. Cooled infrared off-axis freeform three-mirror system design with convenience in testing and assembly. Applied Optics, 61, 10794-10800(2022).

[7] Helong Wang, Jianfa Chen, Haoyang Huang, . Development of off-axis three-mirror system based on free-form surface. Infrared and Laser Engineering, 52, 20220523(2023).

[8] Xiwen Jiang, Xuezhi Ja, Shanshan Cong. Application of freeform surfaces in cooled off-axis three-mirror optical system. Infrared and Laser Engineering, 47, 0918004(2018).

[9] G D Wassermann, E Wolf. On the theory of aplanatic aspheric systems. Proceedings of the Physical Society. Section B, 62, 2(1949).

[10] J B Volatier, G Druart. Differential method for freeform optics applied to two-mirror off-axis telescope design. Optics Letters, 44, 1174-1177(2019).

[11] J C Miñano, P Benítez, W Lin, et al. An application of the SMS method for imaging designs. Optics Express, 17, 24036-24044(2009).

[12] Y Nie, H Thienpont, F Duerr. Multi-fields direct design approach in 3D: calculating a two-surface freeform lens with an entrance pupil for line imaging systems. Optics Express, 23, 34042-34054(2015).

[13] T Yang, J Zhu, W Hou, et al. Design method of freeform off-axis reflective imaging systems with a direct construction process. Optics Express, 22, 9193(2014).

[14] Y Zhong, H Gross. Initial system design method for non-rotationally symmetric systems based on Gaussian brackets and Nodal aberration theory. Optics Express, 25, 10016-10030(2017).

[15] Z Qu, X Zhong, K Zhang, et al. Automatic initial configuration in off-axis reflective optical system design using combined nodal and Seidel aberration. Applied Optics, 61, 3630-3640(2022).

[16] K Thompson. Description of the third-order optical aberrations of near-circular pupil optical systems without symmetry. Journal of the Optical Society of America A, 22, 1389-1401(2005).

[17] [17] Sch T. Misalignment induced nodal aberration fields their use in the alignment of astronomical telescopes[D]. lo: University of Central Flida, 2010.