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Fiber Optics
How Fiber Optics Was Invented
The History of Fiber Optics from Bell's Photophone to
Corning Researchers
by Mary Bellis
Fiber optics is the contained
transmission of light through long fiber rods of either glass or plastics.
The light travels by process
of internal reflection.
The core medium of the rod or
cable is more reflective than the material surrounding the core.
That causes the light to keep
being reflected back into the core where it can continue to travel down the
fiber.
Fiber optic cables are used
for transmitting voice, images, and other data at close to the speed of light.
Who Invented Fiber Optics
Corning Glass
researchers Robert Maurer, Donald Keck, and Peter Schultz invented
fiber optic wire or "Optical Waveguide Fibers" (patent #3,711,262)
capable of carrying 65,000 times more information than copper wire, through
which information carried by a pattern of light waves could be decoded at a destination
even a thousand miles away.
Fiber optic communication
methods and materials invented by them opened the door to the
commercialization of fiber optics.
From long-distance telephone
service to the Internet and medical devices such as the endoscope, fiber
optics are now a major part of modern life.
Timeline
· 1854 - John Tyndall
demonstrated to the Royal Society that light could be conducted through a
curved stream of water, proving that a light signal could be bent.
· 1880 – Alexander Graham Bell invented
his "Photophone," which transmitted a voice signal on a beam of
light. Bell focused sunlight with a mirror and then talked into a mechanism
that vibrated the mirror. At the receiving end, a detector picked up the
vibrating beam and decoded it back into a voice the same way a phone did with
electrical signals. However, many things—a cloudy day, for instance—could
interfere with the Photophone, causing Bell to stop any further research with
this invention.
· 1880 - William Wheeler invented
a system of light pipes lined with a highly reflective coating that illuminated
homes by using light from an electric arc lamp placed in the basement and
directing the light around the home with the pipes.
· 1888 - The medical team of Roth
and Reuss of Vienna used bent glass rods to illuminate body cavities.
· 1895 - French engineer Henry
Saint-Rene designed a system of bent glass rods for guiding light images in an
attempt at early television.
· 1898 - American David Smith
applied for a patent on a bent glass rod device to be used as a surgical
lamp.
· 1920's - Englishman John Logie
Baird and American Clarence W. Hansell patented the idea of using arrays of
transparent rods to transmit images for television and facsimiles respectively.
· 1930 - German medical student
Heinrich Lamm was the first person to assemble a bundle of optical fibers to
carry an image. Lamm's goal was to look inside inaccessible parts of the body.
During his experiments, he reported transmitting the image of a light bulb. The
image was of poor quality, however. His effort to file a patent was denied
because of Hansell's British patent.
· 1954 - Dutch scientist Abraham
Van Heel and British scientist Harold. H. Hopkins separately wrote papers on
imaging bundles. Hopkins reported on imaging bundles of unclad fibers while Van
Heel reported on simple bundles of clad fibers. He covered a bare fiber with a
transparent cladding of a lower refractive index. This protected the fiber
reflection surface from outside distortion and greatly reduced interference
between fibers. At the time, the greatest obstacle to a viable use of fiber
optics was in achieving the lowest signal (light) loss.
· 1961 - Elias Snitzer of
American Optical published a theoretical description of single-mode fibers, a
fiber with a core so small it could carry light with only one waveguide mode.
Snitzer's idea was okay for a medical instrument looking inside the human, but
the fiber had a light loss of one decibel per meter. Communications devices
needed to operate over much longer distances and required a light loss of no
more than 10 or 20 decibels (measurement of light) per kilometer.
· 1964 - A critical (and
theoretical) specification was identified by Dr. C.K. Kao for long-range
communication devices. The specification was 10 or 20 decibels of light
loss per kilometer, which established the standard. Kao also illustrated the
need for a purer form of glass to help reduce light loss.
· 1970 - One team of researchers
began experimenting with fused silica, a material capable of extreme purity
with a high melting point and a low refractive index. Corning Glass researchers
Robert Maurer, Donald Keck and Peter Schultz invented fiber optic wire or
"Optical Waveguide Fibers" (patent #3,711,262) capable of carrying
65,000 times more information than copper wire. This wire allowed for
information carried by a pattern of light waves to be decoded at a destination
even a thousand miles away. The team had solved the problems presented by Dr.
Kao.
· 1975 - The United States
government decided to link the computers at the NORAD headquarters at Cheyenne
Mountain using fiber optics to reduce interference.
· 1977 - The first optical
telephone communication system was installed about 1.5 miles under
downtown Chicago. Each optical fiber carried the equivalent of 672 voice
channels.
· By the end of the century, more
than 80 percent of the world's long-distance traffic was carried over optical
fiber cables and 25 million kilometers of the cable. Maurer, Keck, and
Schultz-designed cables have been installed worldwide.
Glass Fiber Optics at the US Army Signal Corp
The following information was
submitted by Richard Sturzebecher. It was originally published in the Army Corp
publication Monmouth
Message.
In 1958, at the US Army
Signal Corps Labs in Fort Monmouth New Jersey, the manager of Copper Cable and
Wire hated the signal transmission problems caused by lightning and water.
He encouraged Manager of
Materials Research Sam DiVita to find a replacement for copper wire.
Sam thought glass, fiber, and
light signals might work, but the engineers who worked for Sam told him a glass
fiber would break.
In September 1959, Sam DiVita
asked 2nd Lt. Richard Sturzebecher if he knew how to write the formula for a
glass fiber capable of transmitting light signals.
DiVita had learned that
Sturzebecher, who was attending the Signal School, had melted three triaxial
glass systems using SiO2 for his 1958 senior thesis at Alfred University.
Sturzebecher knew the answer.
While using a microscope to measure the index-of-refraction on SiO2
glasses, Richard developed a severe headache.
The 60 percent and 70 percent
SiO2 glass powders under the microscope allowed higher and higher amounts
of brilliant white light to pass through the microscope slide and into his
eyes.
Remembering the headache and
the brilliant white light from high SiO2 glass, Sturzebecher knew that the
formula would be ultra pure SiO2.
Sturzebecher also knew that
Corning made high purity SiO2 powder by oxidizing pure SiCl4 into SiO2. He
suggested that DiVita use his power to award a federal contract to Corning to
develop the fiber.
DiVita had already worked with
Corning research people. But he had to make the idea public because all
research laboratories had a right to bid on a federal contract.
So in 1961 and 1962, the idea
of using high purity SiO2 for a glass fiber to transmit light was made public
information in a bid solicitation to all research laboratories.
As expected, DiVita awarded
the contract to Corning Glass Works in Corning, New York in 1962.
Federal funding for glass
fiber optics at Corning was about $1,000,000 between 1963 and 1970.
Signal Corps Federal funding
of many research programs on fiber optics continued until 1985, thereby seeding
this industry and making today's multibillion-dollar industry that eliminates
copper wire in communications a reality.
DiVita continued to come to
work daily at the US Army Signal Corps in his late 80's and volunteered as a
consultant on nanoscience until his death at age 97 in 2010.
Mary Bellis
·
New York-based film producer and director
· Singled
out by Forbes magazine for her writing on inventors.
· Known
in art and independent film circles by the name CalmX
· Creator
of computer-generated art
Experience
Mary
Bellis was a former writer for ThoughtCo, where she covered inventors for 18
years. She was a freelance writer, film producer, and director. In
addition, Forbes Best of the Web credited her for creating the number one
online destination for information about inventors and inventions. Her
writing has been reprinted and referenced in numerous educational books and articles.
She was known for her short independent films and documentaries,
including one on Alexander Graham Bell. She specialized in making and
exhibiting computer-generated art, while working as an animator, journalist and
an independent video game developer. She died on March 28, 2015.
Education
Mary
Bellis held a Master of Fine Arts in film and animation from the San
Francisco Art Institute.
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