Images and Diffraction

In this chapter, we discuss two subjects in which diffraction is the dominant process in image formation. The first argument, developed in the first two sections, is the Abbe theory of image formation. The theory is valid in general, but is easier to understand under conditions of coherence. The second argument, developed in the subsequent sections, deals with those actual three-dimensional images known as holograms. In a hologram, both the amplitude and the phase of the wave produced by the object are recorded, using coherent illumination.