A Simple Proof of Damien’s Theorem and Duality in Theory of the Zero-Distance Phase Front

Figure 6

The zero-distance phase front with respect to vertex of the homocentric beam of light rays. (a) The ray refracted at point of the surface goes in the opposite direction for the distance () to the point . (b) The ray reflected at point of the surface goes in the opposite direction for the distance to the point .

(a)

(b)