1. Paraboloidal reflector antennas with an arbitrarily-defocused feed are investigated. And some interesting phenomena are observed.

2. Each Collimator is an off-axis paraboloidal mirror (OAP) with /8 (633 nm) surface accuracy and an enhanced aluminum reflective coating

3. FIGURE 129: Paul-Baker three-mirror anastigmatic Aplanat.The basic arrangement (left) consists from a concave paraboloidal primary (P), convex spherical secondary (S) and concave spherical tertiary (T).The only remaining third-order aberration is field curvature, which can be corrected by extending secondary-to-tertiary separation and aspherizing the secondary (right).