While working to improve the resolution of an electron microscope, a brilliant man named Dennis Gabor had developed a theory on Holography. This dates back to the year of 1947. Dennis Gabor is a British/Hungarian scientist who created the word Holography from Greek terms. He used the word holos, meaning "whole," and gramma, meaning "message." Gabor characterized his work as "an experiment in serendipity" that was begun too soon. The next decade brought about frustration in Holography because light sources available at the time were not coherent.
In 1960 a breakthrough came forth. The invention of the laser had pure and intense light that was well suited for the making of holograms. Emmett Leith and Juris Upatnieks of the University of Michigan both had realized that Holography could be used as a 3-D visual medium in 1962. After reading Gabor's paper they decided to duplicate Gabor's technique. Gabor's technique was using the laser and an off axis technique borrowed from their work in the development of side reading radar. The outcome of this experiment was the first laser transmission hologram of 3-D objects. The transmission holograms that Leith and Upatnieks created produced images with clarity and realistic depth. The only issue was that they required laser light to view the holographic image.
The experimental work of both these men led to standardization of the equipment used to make holograms. Thousands of laboratories and studios today possess the necessary equipment. They are the following: A continuous wave laser, optical devices, such as, lens, mirrors, and beam splitters which is used to direct laser light, a film holder, and an isolation table on which exposures are made.
Stability is an essential trait because movement as small as a quarter wave length of light during exposures of a few minutes or even seconds can spoil a hologram completely. The staple of holographic methodology is the basic of the off-axis technique. The creation of a hologram is quite extensive. "A beam of laser light is visually separated into two beams. One, the reference beam, is directed toward a piece of holographic film and expanded (its diameter increased) so that the light covers the film evenly and completely. The second (object) beam is directed at the subject of the composition and similarly expanded to illuminate it (Vacca, 16)." The object beam carries information about the location, size, shape, and the texture of the subject when the object beam reflects off of it. "Some of this reflected object beam then meets the reference beam at the holographic film, producing an interference pattern which is recorded in the light sensitive emulsion (Vacca, 16)." The hologram is illuminated at the same angle as the reference beam during the original exposure to reveal the 3-D image after the film is developed.
Another great experiment that occurred in 1962 was by Dr. Uri N. Denisyuk of the U.S.S.R. He combined...