Wednesday, April 25, 2012

Uses

 Medical

 Military

 Television

 Telecommunications

 Networking


Fiber optics is the evolution of technology. In the future, I think almost all communications will use fiber optics.

Parts of a fiber

  • Core - Thin glass center of the fiber where the light travels
  • Cladding - Outer optical material surrounding the core that reflects the light back into the core
  • Buffer coating - Plastic coating that protects the fiber from damage and moisture




  • Optical fibers come in two types:
    • Single-mode fibers
    • Multi-mode fibers





    Source : http://computer.howstuffworks.com/fiber-optic1.htm

    Tuesday, April 24, 2012

    Communications

    Fiber-optic communication is a method of transmitting information from one place to another by sending pulses of light through an optical fiber. The light forms an electromagnetic carrier wave that is modulated to carry information.

    Optical fiber can be used as a medium for telecommunication and computer networking because it is flexible and can be bundled as cables. It is especially advantageous for long-distance communications, because light propagates through the fiber with little attenuation compared to electrical cables.

    For short distance applications, such as a network in an office building, fiber-optic cabling can save space in cable ducts. This is because a single fiber can carry much more data than electrical cables such as standard category 5 Ethernet cabling, which typically runs at 1 Gbit/s. Fiber is also immune to electrical interference because there is no cross-talk between signals in different cables, and no pickup of environmental noise.



    Non-armored fiber cables do not conduct electricity, which makes fiber a good solution for protecting communications equipment in high voltage environments, such as power generation facilities, or metal communication structures prone to lightning strikes. They can also be used in environments where explosive fumes are present, without danger of ignition. Wiretapping is more difficult compared to electrical connections, and there are concentric dual core fibers that are said to be tap-proof.


    Advantages over electrical transmission


    -    Immunity to electromagnetic interference, including nuclear electromagnetic pulses
    -    High electrical resistance, making it safe to use near high-voltage equipment or between areas with different earth potentials.
    -    Lighter weight. Important, for example, in aircraft.
    -    No sparks. Important in flammable or explosive gas environments.
    -    Not electromagnetically radiating, and difficult to tap without disrupting the signal. Important in high-security environments.
    -    Much smaller cable size. Important where pathway is limited, such as networking an existing building, where smaller channels can be drilled and space can be saved in existing cable ducts and trays.




    Sources : http://www.ntt.co.jp/news/news06e/0609/060929a.html
    http://www.toddulmer.com/work/lee_ulmerCLEO2006.pdf

    Fiber Optic History

    For centuries, glass has been drawn into fibers. Optical communication systems, however date back two centuries, to the "optical telegraph" that French engineer Claude Chappe invented in the 1790s. His system was a series of semaphores mounted on towers, where human operators relayed messages from one tower to the next.

    In 1854, John Tyndall, a British physicist, demonstrated that light could travel through a curved stream of water thereby. He proved this by setting up a tank of water with a pipe that ran out of one side. As water flowed from the pipe, he shone a light into the tank into the stream of water. As the water fell, an arc of light followed the water down. He proved that light signals could be bent.


    Heinrich Lamm was the first person to transmit an image through a bundle of optical fibers in 1930.
    In 1973, Bell Laboratories developed a modified chemical vapor deposition process that heats chemical vapors and oxygen to form ultra-transparent glass that can be mass-produced into low-loss optical fiber. This process still remains the standard for fiber-optic cable manufacturing.

    In the late 1970s and early 1980s, telephone companies began to use fibers extensively to rebuild their communications infrastructure.

    Sprint was founded on the first nationwide, 100 percent digital, fiber-optic network in the mid-1980s.

    The first all-optic fiber cable, TPC-5, that uses optical amplifiers was laid across the Pacific Ocean in 1996.

    Today, a variety of industries including the medical, military, telecommunication, industrial, data storage, networking, and broadcast industries are able to apply and use fiber optic technology in a variety of applications.







    Sources : http://www.timbercon.com/history-of-fiber-optics/
    http://www.sff.net/people/jeff.hecht/history.html

    Benefits of Fiber Optic Cable




    Fiber Optic Cable is a thin, flexible, transparent fiber that acts as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of optical fibers is known as fiber optics. Optical fibers are widely used in fiber-optic communications, which permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communication. Fibers are used instead of metal wires because signals travel along them with less loss and are also immune to electromagnetic interference. Fibers are also used for illumination, and are wrapped in bundles so they can be used to carry images, thus allowing viewing in tight spaces. Specially designed fibers are used for a variety of other applications, including sensors and fiber lasers.




    Source : http://www.citi-llc.com/Networking/fiberOptic.html

    Intro: What are optical fibers?

    Optical fiber (or "fiber optic") refers to the medium and the technology associated with the transmission of information as light pulses along a glass or plastic strand or fiber. Optical fiber carries much more information than conventional copper wire and is in general not subject to electromagnetic interference and the need to retransmit signals. Most telephone company long-distance lines are now made of optical fiber. Transmission over an optical fiber cable requires repeaters at distance intervals. The glass fiber requires more protection within an outer cable than copper.




    Source : http://searchtelecom.techtarget.com/definition/optical-fiber