What is Free Space Optical Communication

The free-space optical communications technology is emerging as an attractive substitute to RF communications. It can satisfy the current demands for higher bandwidth to the customer. Atmospheric turbulence is a major obstacle in wireless optical communication systems. To fully utilize the terabit capacity of FSO system, it has to overcome various challenges offered by the heterogeneous nature of the atmospheric channel. Currently, FSO communication through atmospheric turbulence under adverse weather conditions is an active research topic. A lot of studies and experiments have been carried out on the effect of attenuation due to atmospheric turbulence; but still, much more research is necessary for fulfilling the current demands and commercial needs for implementing this technology successfully. This chapter discussed the various limitations of FSO system which are faced during data transmission through the atmospheric channel and various ways to improve the performance regarding BER, outage probability, and channel capacity.