摘要：Free-space optical communication (FSO) systems (in space and inside the atmosphere) have developed in response to a growing need for high-speed and tap-proof communication systems. FSO can carry full-duplex data at Gbps rates over metropolitan distances of a few city blocks to a few kilometers. FSO system requires capital outlay less compared to ground based fiber-optic technologies. FSO systems can be used in metro network extensions. Organizations can deploy FSO to extend existing fiber network to connect to new networks. FSO can also act as back up for fiber optic system. Keywords — FSO (Free space optics), RZ (Return to zero), NRZ (Non return to zero), NRZ RC(Non return to zero raised cosine), RZ RC (Return to zero raised cosine), OOK (On off keying)
