Intrinsic apodization effect in a compact two-mirror system with a spherical primary mirror
In so-called compact two-mirror focusing and afocal systems the secondary mirror is situated at the paraxial focus of the spherical primary mirror. The peculiar conelike shape of the secondary is chosen to eliminate the spherical aberration. Thus the systems are stigmatic, but they have a great offence against the sine condition (OSC), creating uneven distribution of energy on the surface of the o
