Zhu Liwei, Xie Hongbo, Chen Jie, Yang Tong, Yang Lei
Appl Opt. 2023 Oct 10;62(29):7773-7782. doi: 10.1364/AO.500149.
An off-axis four-mirror optical system has the advantages of a wide field of view (FOV) and a small telephoto ratio. However, it will bring difficulties in assembly and detection. Here we report an off-axis four-mirror free-form telescope with a long focal length and a wide field of view based on two integration mirrors. The initial structure of a coaxial four-mirror optical system is established based on the Seidel aberration theory. A Zernike Fringe free-form surface is introduced to correct aberrations. By gradually increasing the entrance pupil diameter and the FOV, we finally obtain an off-axis four-mirror telescope with a FOV of 0.4×20, an F-number of 11.5, a long focal length of 2000 mm, and a volume of 360×400×600 . In addition, four mirrors remain coaxially aligned, remarkably facilitating detection and adjustment. The proposed off-axis four-mirror telescope, with double integration mirrors, holds great potential for application in aerospace remote sensing observations.
离轴四镜光学系统具有视场（FOV）宽和远摄比小的优点。然而，它会给装配和检测带来困难。在此，我们报道一种基于两个集成镜的长焦距、宽视场离轴四镜自由曲面望远镜。基于赛德尔像差理论建立了同轴四镜光学系统的初始结构。引入泽尼克条纹自由曲面来校正像差。通过逐渐增大入瞳直径和视场，我们最终获得了一个视场为0.4×20、F数为11.5、长焦距为2000毫米、体积为360×400×600的离轴四镜望远镜。此外，四个镜保持同轴对准，极大地便于检测和调整。所提出的具有双集成镜的离轴四镜望远镜在航空航天遥感观测中具有巨大的应用潜力。
