Performance Analysis of fibre Channel Dispersion and its effect on Optical Communication

Abstract

The bandwidth that an optical fiber can support is limited by the dispersion in an optical fiber. As the demand of bandwidth increases, the spacing between successive pulses and the pulse duration of the signals have to decrease to meet the demand. However, the short optical pulses used may not necessarily be monochromatic, in another words they often contain more than one frequency components. In this case, chromatic dispersion in the optical fibre is the dominant factor limiting the transmission rate of nowadays telecommunication systems. Dispersion limits the length of fibre and effect on inter symbol interference (ISI) of the signal. The primary dispersion in a multi-mode step index fiber is the intermodal dispersion caused by different modes in the fiber traveling different distances to reach from one point to another a narrow pulse at the input divides its energy into different modes which now take different lengths of time to reach the detector. The result is a broadening of the pulse. In the graded index fiber, the intermodal dispersion is greatly reduced and is eliminated in a single mode fiber. The pulse broadening may cause overlapping of neighboring pulses. To avoid this, dispersion compensation techniques are used to make sure long and error free transmission. In this paper the effect of dispersion and the method to compensate it using MATLAB coding and SIMULINK modeling of the optical communication system are shown.