
Modern holography dates from 1947, when Dennis Gabor, a
scientist researching the ways to improve the resolution
of the electron microscope, developed what he called holography.
In fact, in 1948 he coined the term hologram from the Greek
words "holos", meaning "whole," and "gramma",
meaning "message". Gabor did not have at his disposal
coherent light source needed for continuing his work.Thirteen
years later, in 1960, the LASER was invented and the serious
work in holography began. In 1971 Dr. Dennis Gabor was awarded
the Nobel Prize in Physics for his work in holography.
Two researchers, Emmett
Leith and Juris Upatnieks, from the University
of Michigan, in 1962,
theorized that holography could be used as a three dimensional
visual presentation. These individuals decided to apply
Gabor's theory with the newly invented laser light sources.
The result was the first laser transmission hologram of
3D objects. These transmission holograms produced images
with clarity and realistic depth. Unfortunately, these
transmission holograms required laser light to view the
holographic image. The work of Leith and Upatnieks led
to standardization of the equipment used to make holograms.
Today, thousands of laboratories and studios possess the
necessary equipment: a continuous wave laser, optical devices
(lens, mirrors and beam splitters) for directing laser
light, a film holder and an isolation table on which exposures
are made. Stability is absolutely essential because movement
as small as a quarter wave-length of light during exposures
of a few minutes or even seconds can completely spoil a
hologram. The basic off-axis technique that Leith and Upatnieks
developed is still the staple of holographic methodology.
In 1960 the pulsed-ruby laser
was developed by Dr. T.H. Maimam of the Hughes Aircraft
Corporation. This laser system (unlike the continuous wave
laser normally used in holography) emits a very powerful
burst of light that lasts only a few nanoseconds (a billionth
of a second). It effectively freezes movement and makes
it possible to produce holograms of high-speed events,
such as a bullet in flight, and of living subjects. The
first hologram of a person was made in 1967, paving the
way for a specialized application of holography: pulsed
holographic portraiture.
Like so many scientific advancements,
holography was simultaneously being developed by other
scientists. It was a Russian, Uri Denisyuk, who, in 1962,
brought the work of Gabriel Lippmann (1908 Nobel Laureate)
to holography and produced the first white-light
reflection holograms that could be viewed in ordinary incandescent
light bulb.
The 1967 World Book Encyclopedia
Science Yearbook contained what is arguably the first mass-distributed
hologram, a 4"x3" transmission view of chess
pieces on a board. An article describing the production
of the hologram and basic information about the history
of holography accompanied it. A .05 watt He-Ne laser was
used on a nine-ton granite table in a 30-second exposure
to make the original from which all the copies were produced.
The next important
steps in the development of the holography were made by Stephen
Benton, who, in 1968, invented white - light transmission
holography. White-light holography allows the image to be
viewed in ordinary white light. Undoubtedly, it was the brilliant
rainbow colors that attracted artists to this new holographic
technology. This type of hologram can be viewed in ordinary
white light creating a "rainbow" image
from the seven colors which make up the white
light. This type of hologram was called "rainbow hologram".
The most important result
of Stephen Benton's work was that it led to the ability
to mass-produce holographic images using optical embossing
techniques. Embossing allowed the images to be reproduced
by a press that stamped the image onto
plastic surfaces.
With this technique, developed
by Michael Foster in 1974 and brought to commercial viability
by Steve McGreww in 1979, holographic information is transferred
from light sensitive glass plates to nickel embossing shims.
The holographic images are "printed" by stamping
the interference pattern onto plastic. The resulting hologram
can be duplicated millions of times for a few cents apiece.
Consequently, embossed holograms are now being used by
the publishing, advertising, packaging, banking
and security industries.
|