Investigation and Analysis of Free Space Optical Link for Different Atmospheric Turbulences, Beam divergences and modulation formats

In this work, a high speed free space optical (FSO) system is demonstrated by incorporating cost effective technique called spectrum slicing. Major achievement of the research is to use the nonlinear effect called self phase modulation as an application in spectrum slicing. A multichannel system is realized using the spectrum slices and each supports data rate of 2.5 Gbps over 5 km link distance. Investigation is carried out for different performance degrading turbulences that affect the FSO channels such as fog and haze. Different beam divergences and aperture size of transmitter and receiver is also studied for NRZ and RZ. Outcomes after analyses revealed that NRZ in large antenna sizes under clear weather for minimum values of beam divergence is better to use than RZ modulation format.