Extinction Coefficient For Fog Attenuation Via Non-linear Medium

Abstract

Due to various inherent advantages, the FSO (Free Space Optics) is a dominant competitor for last mile connectivity in recent years. FSO systems transmit data in the form of light therefore major challenge in the implementation of these systems is weather effects on optical signals. The fog is one of the major cause of attenuation in FSO and several studies have been completed on fog. Various fog attenuation models based on theoretical and empirical approach were designed and proposed to convert visibility statistics into fog attenuation factor. In last decade several researchers attempted to compare these models with practical FSO link but no one has achieved accurate results because thesemodels were designed on the basis of theoretical assumptions only. These assumptions are based on three ideas that the fog particles are homogenous, that the transmission medium is homogeneous and that the linearity exists in transmission medium. In this research, all key assumptions of Mie theory were critically reviewed. Only idea of linearmedium has been considered and assumed as a non-linear medium for this research. Though two other assumptions of Mie theory remain unchanged. In this paper, the calculation of extinction coefficient for non-linear nature of the medium with homogeneous particles and homogeneous medium, merely considered for the simulation and results were compared with existing Mie theory assumptions.