How Fiber Optics Works


    A single optical fiber has three parts called a buffer coating, cladding, and the core.  The buffer coating is the plastic coating that protects the fiber from damage and moisture.  The cladding is the outer optical material surrounding the core that reflects the light back into the core.  The core is the glass center of the fiber where the light travels.  The picture below shows a detailed diagram of a fiber wire.


Parts of a single optical fiber

   Photo courtesy of ‘How Stuff Works’

Another picture is shown below that includes an additional components of a fiber wire, but it has the same concept as the picture above.


Components of a Fiber Optic Wire



    There are three basic elements in a point-to-point fiber optic transmission system called an optical transmitter, fiber optic cable, and an optical receiver.  An optical transmitter converts an electrical analog or digital signal into a corresponding optical signal.  A fiber optic cable consists of one or more glass fibers, which as a waveguides.  An optical receiver converts the optical signal back into a replica of the original electric signal.  The diagram below shows the flow of information from the signal input to the signal output.


Picture from:


    Fiber optics uses a communication system in order to relay messages over long distances.  A fiber optic relay system consists of a transmitter, optical fiber, optical regenerator, and an optical receiver.  The transmitter produces and encodes the light signals.  The optical fiber conducts the light signals over a distance.  The optical regenerator may be necessary to boost the light signal for long distances and the optical receiver receives and decodes the light signal.  This system allows messages to be easily received and translated.