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.
Process of production