Multi-Channel Communication in Free-Space Optical Networks for the Last-Mile

Traditionally, Free-Space Optical (FSO) communications use a single transmitting antenna (Laser/VCSEL/LED) and a receiving antenna a photo-detector for single channel communication between two nodes. This paper explores multi-channel free-space optical communication system using 2-dimensional multi-element optical antennas. Unlike in RF, by "Channel", the authors mean spatial channel rather than frequency channel. Multi-element array design for FSO communication is very attractive since it offers high aggregate bandwidth and link robustness due to spatial diversity.