Design of an anastigmatic three-mirror telescope using freeform surfaces

This paper proposes the design of an anastigmatic three-mirror telescope using freeform surfaces for the correction of spherical aberration, coma, astigmatism, and field curvature, allowing a wide field of view (FOV) and high resolution. For the structure of this telescope, it is proposed to use only two optical elements where the primary and tertiary mirrors are integrated into an only optical element and the secondary mirror in the other, thus achieving a considerable reduction in the difficulty of alignment and assembly. To achieve a high performance of the telescope, the system was decentered (off-axis design), avoiding the loss of energy due to the obscuration of the M-2 in the on-axis system. In addition, to solve the difficult access to the focus.