In a concentric two-mirror unit magnification system, only meridional imagery suffers from higher-order field curvature and residual aberration. Here a new parameter is introduced to optimize these two problems. It is demonstrated that they are simultaneously optimized when the convex-mirror radius is exactly half of that of the concave mirror. Then the inclination of sagittal and meridional fields is balanced, and residual aberration is minimized at several times less than that of the concentric system.
© 1983 Optical Society of America
Akiyoshi Suzuki, "Complete analysis of a two-mirror unit magnification system. Part 2," Appl. Opt. 22, 3950-3956 (1983)