Holographic History

Holography dates from 1947, when British/Hungarian scientist Dennis Gabor developed the theory of holography while working to improve the resolution of an electron microscope. Gabor, who characterized his work as "an experiment in serendipity" that was "begun too soon, " coined the term hologram from the Greek words holos, meaning "whole, " and gramma, meaning "message." (see Gabor's autobiography)

Gabor's first paper on holography evoked immediate response from scientists worldwide. Among those who made important contributions to the development of the technique were G.L. Rogers, A.B. Baez, H. El-Sum, P. Kirkpatrick and M.E. Haine. In these early years, the mercury arc lamp was the most coherent light source available for making holograms. Because of the low coherency of this light, it was not possible to produce holograms of any depth, thus restricting research. Despite equipment limitations, these researchers identified many of the properties of holography and further elaborated on Gabor's theory. Most important, they extended their understanding of the process and its potential to another generation of scientists.

Gabor's holography was limited to film transparencies using a mercury arc lamp as the light source. His holograms contained distortions and an extraneous twin image. Further development in the field was stymied during the next decade because light sources available at the time were not truly "coherent" (monochromatic or one-color, from a single point, and of a single wavelength).

Dr. Dennis Gabor signs a copy of the Museum of Holography's inaugural exhibition catalogue, "Through The Looking Glass, " during his historic visit to the museum on March 17, 1977. (Photo by Paul D. Barefoot)

This barrier was overcome in 1960 with the invention of the laser, whose pure, intense light was ideal for making holograms. For the next ten years, holography techniques and applications mushroomed.

In 1962 Emmett Leith and Juris Upatnieks of the University of Michigan recognized from their work in side-reading radar that holography could be used as a 3-D visual medium. In 1962 they read Gabor's paper and "simply out of curiosity" decided to duplicate Gabor's technique using the laser and an "off-axis" technique borrowed from their work in the development of side-reading radar. The result was the first laser transmission hologram of 3-D objects (a toy train and bird). These transmission holograms produced images with clarity and realistic depth but required laser light to view the holographic image.

"Train and Bird" is the first hologram ever made with a laser using the off-axis technique. This pioneer image was produced in 1964 by Emmett Leith and Juris Upatnieks at the University of Michigan only four years after the invention of the laser