|
 Holography dates from 1947,
when British (native of Hungary) scientist Dennis
Gabor developed the theory of holography while
working to improve the resolution of an electron
microscope.Gabor coined the term hologram from the
Greek words holos, meaning "whole," and
gramma, meaning "message". 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).
This
barrier was overcome in 1960 by Russian scientists
N. Bassov and A. Prokhorov and
American scientist Charles Towns with the
invention of the laser, whose pure, intense light
was ideal for making holograms.
In that year the pulsed-ruby laser was developed
by Dr. T.H. Maimam. 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.
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.
Their pioneering work 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.
 Also in 1962
Dr. Yuri N. Denisyuk from Russia combined
holography with 1908 Nobel Laureate Gabriel Lippmann's
work in natural color photography. Denisyuk's
approach produced a white-light reflection hologram
which, for the first time, could be viewed in light
from an ordinary incandescent light bulb.
Another
major advance in display holography occurred in
1968 when Dr. Stephen A. Benton
invented white-light transmission holography while
researching holographic television at Polaroid Research
Laboratories. This type of hologram can be viewed
in ordinary white light creating a "rainbow"
image from the seven colors which make up white
light. The depth and brilliance of the image and
its rainbow spectrum soon attracted artists who
adapted this technique to their work and brought
holography further into public awareness.
Benton's invention is particularly significant because
it made possible mass production of holograms using
an embossing technique. These holograms 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, and banking
industries.
In
1972 Lloyd Cross developed the integral
hologram by combining white-light transmission holography
with conventional cinematography to produce moving
3-dimensional images. Sequential frames of 2-D motion-picture
footage of a rotating subject are recorded on holographic
film. When viewed, the composite images are synthesized
by the human brain as a 3-D image.
In
70's Victor Komar and his colleagues at the All-Union
Cinema and Photographic Research Institute (NIFKI)
in Russia, developed a prototype for a projected
holographic movie. Images were recorded with a pulsed
holographic camera. The developed film was projected
onto a holographic screen that focused the dimensional
image out to several points in the audience.
Holographic artists
have greatly increased their technical knowledge of the discipline and now contribute to
the technology as well as the creative process. The art form has become international,
with major exhibitions being held throughout the world.
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