a. Verify that the reconstructed wavefront from the hologram of a point source produces bo...

a. Verify that the reconstructed wavefront from the hologram of a point source produces both the real and virtual images shown in Figure 1. First, find the irradiance at the film due to the superposition of a plane and a spherical wave. Then, find the amplitude of the light transmitted by the developed film when irradiated by the reference beam. Interpret the terms as done in the discussion of a hologram of a three-dimensional subject.

---

b. Show that the phase delay of the diverging subject beam, at a point on the film a distance y from the axis, is given by πy2/λd, where d is the distance of the point source from the film. This result follows when y ≪ d. Show also that reversal of the phase angle produces a converging spherical wavefront associated with the real image on reconstruction.

Figure 1