FIBER OPTIC COMMUNICATION

An optical fiber is a glass or plastic fiber that is designed for guiding light along its length by total internal reflection fiber optics is the branch of applied science and engineering  concerned with such optical fiber.Fiber optics is the newest way of sending large amounts of data,although it is based on a principle of physics that has been known for several hundred years.Fiber optic links are  used for application ranging from short distance local area networks to world wide data communications.Thin optical fibers around 25µm in diameter are used as a "waveguides" or "light pipes" to transmit optical signal from a light source to a detector senses the light source to a detector senses the light pulses and converts them back.Optical signals travel over large distances in kilometers which leads to extensive use of optical fibers in communication areas.Optical fibers are flexible and guide signals without any need of perfect alignment.For transmission of a large amount of information or communication,a large number of optical fiber are collected in the form of a bundle jacked for mechanical strength.

practical fiber optics system requires the development of reliable sources and detectors,as well as low-loss optical fibers.These systems allow wide band communication within a single building or across oceans,while providing benefits of no electrical interference,low error rate,security and reduced bulk compared to standard wire cables or broadcast links.Optical fiber systems are most suitable foe single point-to-point applications,where there is a minimum of switching or routing,since optical energy is difficult to switch to other fiber paths.

Test instruments for fiber optics are very different from those for conventional electronic signals.An optical source generates light of a signal wavelength (frequency) with imprecise power levels,so test procedures are changed to accommodate this situation and procedures are changed to accommodate this situation and produce accurate results.Time domain reflectronometry for the electronic signals are modified for use with optical signals and can show nearly every subtlety of the fiber performance,working only from one end of the fiber.