Fiber Optic Cables

   . Network cable which is used for communication through pulses of light.
   . Much effective than wired cables since data is transferred as light with high speed.
   . Consists of number of glass fiber called Optical Fibers which are less in diameter of human hair.

   Optical Fiber:

        . It is a thin glass made of silica into which signal is transmitted as light pulses.
        . Number of these fibers are bundled into the optical cable.
        . Designed for long distance, high performance data transmission.
        . Internet, cable television, telephone systems uses optical fibers.


        . Consists of layers called Core, Cladding and buffer.
        . Core is the glass material in which light signals passes.
        . Cladding covers the core which avoids loss of signal by total internal reflection.
        . Buffer acts as a protective sheet to the entire construction.

    How it works?

        . Transmitters send the electric signals to the optical fiber as light pulses.
        . They travel across the length of cable by total internal reflection and reaches the destination in the speed of light i.e., 3x10^5 km/sec.
        . At the other end, receivers converts these signals into electric signals and then used for further communication.

    Types of Optical Fiber Cables:

         . Single Mode: 
             - It can carry only one wavelength of light. 
              - Has a narrow core diameter.
             - Light travels in one direction, losses are less.
             - Suitable to applications which require long distance communication.

         . Multi Mode:
             - Carries more number of wavelengths of light.
             - Has a wider diameter for core.
             - Different reflecting angles will be there for different modes of signals.
             - Some modes of waves do not follow total internal reflection which may cause losses.

   Advantages of Fiber Optics:

        . Volume of data that fiber optics allows to pass per unit time is far greater than copper wires.
        . Loss of signals is less.
        . Signals travel with same quality for longer distances without any losses.
        . Easy to maintain Fiber optic cables than coaxial or twisted paired cables.
        . Nowadays internet, telephone communications is done through fiber optic cables.