Optical fiber is a cable that accepts and transports signals in the form of light. Optical fiber consists of thin glass fiber that can carry information at frequencies in the visible light spectrum. Optical fiber work on the principle that the core refracts the light and the cladding reflects the light. The core refracts the light and guides the light along its path. The cladding reflects any light back into the core and stops light from escaping through it - it bounds the media.
The basic features of optical fiber are :
» The typical optical fiber consists of a very narrow strand of glass called the cladding.
» A typical core diameter is 62.5 microns.
» Typically cladding has a diameter of 125 minors. Coating the cladding is a protective coating consisting of plastic, it is called the jacket.
» The device generating the message has it in electromagnetic form (electrical signal); this has to be converted into light (i.e. optical signal) to send it on optic fiber cable. The process of converting light to electric signal is done on the receiving side.
Some of the advantages of using fiber optical cable are:
» Small size and light weight: The size of the optical fibers is very small. Therefore a large number of optical fibers can fit into a cable of small diameter.
» Easy availability and low cost: The material used for the manufacturing of optical fibers is Silica glass. This material is easily available. So the optical fibers cost lower than the cables with metallic conductors.
» No electrical or electromagnetic interference: Since the transmission takes place in the form of light rays the signal is not affected due to any electrical or electromagnetic Interference
» Large Bandwidth: As the light rays have a very high frequency in GHz range, the bandwidth of the optical fiber is extremely large.
» No cross talk inside the optical fiber cable. Signal can be sent up to 100 times faster.
Disadvantages of optical fiber cable include the following
» Physical vibration will show up as signal noise.
» Limited physical arc of cable. Bend it too much & it will break.
» Difficult to splice
Optical Fiber