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. Because of its advantages over electrical transmission, optical fibers have largely replaced copper wire communications in core networks in the developed world. The process of communicating using fiber-optics involves the following basic steps:

• Creating the optical signal involving the use of a transmitter
• Relaying the signal along the fiber
• Ensuring that the signal does not become too distorted or weak
• Receiving the optical signal Converting it into an electrical signal.

In information technology, networking is the construction, design, and use of a network, including the physical (cabling, hub, bridge, switch, router, and so forth), the selection and use of telecommunication protocol and computer software for using and managing the network, and the establishment of operation policies and procedures related to the network.

Types of Fiber Optic cable

There are two types of fiber optic cable: * Single-mode fiber - Multi-mode fiber

Single Mode Fiber Optic Cable

Single mode fiber optic cable has a small diameter core that allows only one mode of light to propagate. Because of this, the number of light reflections created as the light passes through the core decreases, lowering attenuation and creating the ability for the signal to travel faster, further.

Single mode fiber is usually 9/125 in construction.  This means that the core to cladding diameter ratio is 9 microns to 125 microns.

Fiber optic termination

Fiber termination can be achieved in two ways:

• By using connectors
• By fusion splicing.

Fusion splicing is done with a specialized instrument. The fiber ends are first stripped of their protective polymer coating. The ends are cleaved with a precision cleaver to make them perpendicular, and are placed into special holders in the fusion splicer.

The splice is usually inspected through a magnified viewing screen to check the cleaves before and after the splice. The splicer uses small motors to align the end faces together, and emits a small spark between electrodes at the gap to burn off dust and moisture. Then the splicer generates a larger spark that raises the temperature above the melting point of the glass, fusing the ends together permanently.

The location and energy of the spark is carefully controlled so that the molten core and cladding do not mix, and this minimizes optical loss. A splice loss estimate is measured by the splicer, by directing light through the cladding on one side and measuring the light leaking from the cladding on the other side. A splice loss under 0.1 dB is typical. The complexity of this process makes fiber splicing much more difficult than splicing copper wire.

There are two principal types of splices: fusion and mechanical.

The basic fusion-splicing apparatus consists of two fixtures on which the fibers are mounted with two electrodes. An inspection microscope assists in the placement of the prepared fiber ends into a fusion-splicing apparatus. The fibers are placed into the apparatus, aligned, and then fused together.