Last time I have discussed the basic definition of holography and hologram. Today I will discuss the process with the help of which hologram is formed or complete picture is recorded:
1. Recording of the hologram.
The recording of hologram is based on the phenomenon of interference. It requires a laser source, a plane mirror or beam splitter, an object and a photographic plate. A laser beam from the laser source is incident on a plane mirror or beam splitter. As the name suggests, the function of the beam splitter is to split the laser beam. One part of splitted beam, after reflection from the beam splitter, strikes on the photographic plate. This beam is called reference beam.
The object beam reflected from the object interferes with the reference beam when both the beams reach the photographic plate. The superposition of these two beams produces an interference pattern (in the form of dark and bright fringes) and this pattern is recorded on the photographic plate. The photographic plate with a recorded interference pattern is called a hologram. The photographic plate is also known as the Gabor zone plate in honor of Denis Gabor who developed the phenomenon of holography.Continue reading “Recording and reconstruction process in holography”