Beam Width and Receiver Apperture Size Effects on the Performance of FSO Link

This paper investigates transmitter beam width effect on the performance of free space optical (FSO) communication system considering atmospheric turbulence, aperture averaging effect and different noises including background noise. A complete FSO system including optical transmitter, receiver and free space channel, is simulated using a complete physical model. Received optical power is used to characterize the signal to noise ratio in different cases. This will be shown that due to scintillation effect and background noise, there is an optimum value for the transmitter beam width.