Abstract:
Fiber optic (or "optical fiber") refers to the medium and the technology associated with the transmission of information as light impulses along a glass or plastic wire or fiber. Fiber optic wire carries much more information than conventional copper wire and is far less subject to electromagnetic interference. Most telephone company long-distance lines are now fiber optic.
Transmission on fiber optic wire requires repeating at distance intervals. The glass fiber requires more protection within an outer cable than copper. For these reasons and because the installation of any new wiring is labor-intensive, few communities yet have fiber optic wires or cables from the phone company's branch office to local customers
History of Fiber optic
In 1880 Alexander Graham Bell invented the photophone. Bell considered this a greater discovery than his other invention, the telephone. With the photophone, Bell would speak into a microphone, which would then cause a mirror to vibrate. The sun's light would strike the mirror, and the vibration of the mirror would transmit light across an open distance of about 656ft (200m). The receiver's mirror would receive the light and cause a selenium crystal to vibrate, causing the noise to come out on the other end. Although the photophone was successful in allowing conversation over an open space, it had a few drawbacks: it did not work at night, in the rain or if someone walked between the signal and receiver. Eventually, Bell gave up on this idea.
It was not until the 1950s that the laser was invented. This device was a finely controlled beam of light that could transmit information over long distances. Unfortunately, the same drawbacks experienced by Alexander Graham Bell also plagued the laser. Although it could be used at night, it did not work during rain, fog or at any time a building was erected between the sender and the receiver.
Dr. Robert Maurer, Peter Schultz and Donald Keck of Corning Incorporated in Corning, New York, came up with the first low loss optical fiber, with less than 20dB/km (decibels per kilometer) loss. Today, single-mode, premium grade fiber is sold with specifications of 0.25 dB/km or better.
In 1977 Corning joined forces with another technological giant, Seimens Corporation, to form Siecor. Corning's extensive work with fiber, coupled with Siemen's cabling technology, helped launch a new era in optical fiber cable and associated products. Today, Siecor is a world leader in the manufacturing of fiber optic cabling system products for voice, data and video communications applications.
In its simplest form fiber optics is a medium for carrying information from one point to another in the form of light. Unlike the copper form of transmission, fiber optics is not electrical in nature. A basic fiber optic system consists of
1) a transmitting device, which generates the light signal
2) an optical fiber cable, which carries the light and
3) a receiver, which accepts the light signal transmitted. The fiber itself is passive and does not contain any active, generative properties.
What is fiber optics?
We're used to the idea of information traveling in different ways. When we speak into a landline telephone, a wire cable carries the sounds from our voice into a socket in the wall, where another cable takes it to the local telephone exchange. Cellphones work a different way: they send and receive information using invisible radio waves—a technology called wireless because it uses no cables. Fiber optics works a third way. It sends information coded in a beam of light down a glass or plastic pipe. It was originally developed for endoscopes in the 1950s to help doctors see inside the human body without having to cut it open first. In the 1960s, engineers found a way of using the same technology to transmit telephone calls at the speed of light (normally that's 186,000 miles or 300,000 km per second in a vacuum, but slows to about two thirds this speed in a fiber-optic cable).
Refer:
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How Does Optical Fiber works?
The inside of an optical cable is composed of many small fiber optic wires inside the outer insulation. The transmitting home theater component takes the digital signal it processes and converts it into pulses of light. The light is then sent through the optical cable and received on the other end. The receiving home theater component then converts the light pulses back into the digital signal.
The light in a fiber-optic cable travels through the core (hallway) by constantly bouncing from the cladding (mirror-lined walls), a principle called total internal reflection. Because the cladding does not absorb any light from the core, the light wave can travel great distances. However, some of the light signal degrades within the fiber, mostly due to impurities in the glass. The extent that the signal degrades depends on the purity of the glass and the wavelength of the transmitted light.
References
https://ddp13fiberoptics.wordpress.com/how-does-an-optical-fiber-transmit-light/
https://en.wikipedia.org/wiki/Optical_fiber
https://www.explainthatstuff.com/fiberoptics.html
https://www.cablestogo.com/learning/library/data-center/history-fiber-optics
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