Compact wide-field off-axis two-mirror system with field corrector

TMA-based obstruction-free off-axis three-mirror systems became popular recently. Although they provide good performance over wide field of view by employing freeform mirrors, the overall dimension and the size of the system are relatively large considering their aperture size and focal length. More compact design is possible in off-axis two-mirror systems combined with field-correcting lens. A linear-astigmatism-free two-mirror system with correcting lens provides a wide field of view in relatively small size. In this paper, design examples of compact wide field two-mirror systems with correcting lens are presented.