Performance analysis of Free Space Optical communication system for S, C and L band

Free Space Optics (FSO) link offers a wide bandwidth with license free bands worldwide. But the link capacity and availability is always a major concern in the different atmospheric conditions. Thus the reliability of the link is highly dependent on weather which attenuates the signal strength under adverse weather. This paper primarily describes the effects of bad weather conditions on FSO link within 500 m range for an attenuation of up to 70 dB/km. The optical wavelength channel allocation for CWDM systems are analyzed for a bit rate of 10 Gbps. Simulation parameters such as Quality factor, minimum BER (bit error rate) and Eye diagram are studied to have the idea of system performance using OPTISYSTEM 7.0 of Optiwave software. Power spectrum at different wavelengths of S-band, C-band and L-band windows are analyzed so that the suitable WDM system based on FSO can be designed.