An Offner System usually consists of two spherical mirrors concentric around the same center, with a magnification m = 1. The light is supposed to be reflected back and forth between the two mirrors. Such an optical system can be conveniently set up with the non-sequential extension in VirtualLab Fusion. In this example, an Offner system is modeled and its imaging property is investigated. By varying the lateral position of the source, it is shown that mirror edges may truncate the field in certain situations, and therefore affect the imaging quality at the detector plane.
