Off-axis three-mirror freeform optical system with large linear field of view

Design of a co-aperture composite imaging system for visible light remote sensing camera and synthetic aperture radar

“…An off-axis three-mirror optical system not only possesses the advantages of a reflective optical system, which allows for the realization of a large aperture and long focal length, but also enables the simultaneous correction of various aberrations such as spherical aberration, coma, and astigmatism. Moreover, it eliminates the central obstruction [5] . The off-axis threemirror system is generally based on the same principles as the coaxial three-mirror system for imaging, as illustrated in represent the radii of the mirrors, ℎ 1 , ℎ 2 , and ℎ 3 represent the apertures of the three mirrors, 𝑑 1 is the distance from 𝑀 1 to 𝑀 2 , 𝑑 2 is the distance from 𝑀 2 to 𝑀 3 , and 𝑘 1 , 𝑘 2 , and 𝑘 3 are the aspheric coefficients for the three mirrors [6] .…”