Rami Arieli: "The
Laser Adventure" Chapter 10 Section 2, page 21
Creation of Image
by Fresnel Zone Plate
When the transparency with Fresnel zones is illuminated
by a parallel beam (plan wave), the result is a real
image of the original point
light source (see figure 10.8).
Figure 10.8: Creation of real and imaginary images
by Fresnel Zone Plate.
The distance of the image from the Fresnel zone plate is "a".
A point light source was used to create the Fresnel zone
plate by interference with the plan wave (
see
figure 10.4). The distance "
a" is equal to the original
distance of the point light source from the film.
In a similar way to the creation of converging wave,
a diverging wave is created.
The continuation of its light rays backward created an imaginary
image of the point light source.