History of Fiber Optics
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John Tyndall
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In 1870, John Tyndall, using a jet of water that flowed from one container to another and a beam of light, demonstrated that light used internal reflection to follow a specific path. As water poured out through the spout of the first container, Tyndall directed a beam of sunlight at the path of the water. The light, as seen by the audience, followed a zigzag path inside the curved path of the water. This simple experiment marked the first research into the guided transmission of light.
William Wheeling, in 1880, patented a method of light transfer called “piping light”. Wheeling believed that by using mirrored pipes branching off from a single source of illumination, i.e. a bright electric arc, he could send the light to many different rooms in the same way that water, through plumbing, is carried throughout buildings today. Due to the ineffectiveness of Wheeling’s idea and to the concurrent introduction of Edison’s highly successful incandescent light bulb, the concept of piping light never took off.
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Alexander
Graham Bell
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That same year, Alexander Graham Bell developed an optical voice transmission system he called the “photophone”. The photophone used free-space light to carry the human voice 656 ft (200 m). Specially placed mirrors reflected sunlight onto a diaphragm attached within the mouthpiece of the photophone. At the other end, mounted within a parabolic reflector, was a light-sensitive selenium resistor. This resistor was connected to a battery that was, in turn, wired to a telephone receiver. As one spoke into the photophone, the illuminated diaphragm vibrated, casting various intensities of light onto the selenium resistor. The changing intensity of light altered the current that passed through the telephone receiver which then converted the light back into speech. Bell believed this invention was superior to the telephone because it did not need wires to connect the transmitter and receiver. Today, free-space optical links find extensive use in metropolitan applications.
The rest, as they say, is history….
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1900: Max Planck introduced a new field of science; quantum physics. He mathematically demonstrated that matter radiates energy in discrete bundles which he named quanta.
1905: Albert Einstein built on the research of Max Planck to show that light is made of packets, later referred to as photons. Einstein received a Nobel prize in 1921 for this breakthrough.
1920s: John Logie Baird in England and Clarence W. Hansell in the United States patented the concept of using hollow pipes to transmit images for television and facsimile systems.
1930s: Heinrich Lamm, a medical student in Munich Germany, reported the transmission of an image of a light bulb through a short bundle of uncladded fibers.
1960s: Theodore Maiman invented the ruby laser. This first laser was bulky and fragile.
Charles Kao and George Hodkham at Standard Telecommunications Laboratories in England, in their landmark theoretical paper, postulated that the light loss in fiber could be dramatically reduced by using amplifiers at intervals to boost the signals.
1970s: Scientists from Corning Glass Work prepared the first batch of optical fiber hundreds of yards long and were able to communicate over it with crystal clear clarity.
Simultaneously a group at Bell Labs developed a semiconductor laser that could operate at room temperature.
Early 1980s: Fibers were produced that were so transparent that a signal could pass through 150 miles of fiber before becoming too weak to detect. The breakthrough came through the realization that pure silica glass fiber, devoid of all of metal impurities, could only be prepared directly from vapor components.
Small optical fiber networks were being installed. In early fiber optic systems, amplifiers were used to regenerate weak signals. Optical devices were used to detect incoming signals. and electronic circuitry converted and amplified the electrical current, then driving a new laser to recreate the optical signal.
1985: S. B. Poole of England's University of Southampton discovered that by splicing a short strand of erbium-doped glass into the main fiber, the system would receive energy from an eternal source and act as a laser it its own right. By amplifying a weak optical signal with out electronic circuitry. This dramatically increased the carrying capacity (100 times) over systems utilizing electronic amplifiers.
1988: First transatlantic fiber cable is laid with glass so transparent that amplifiers are only needed about every 40 miles.
1991: Emmanuel Desurvire of Bell Labs and David Payne and P.J. Meers of England's University of Southampton, produce cable with transmitters built in to the fibers.
1996: Fiber optic cable laid across the Pacific Ocean.
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