Definition: free space optics

A high-speed optical wireless communication system that transmits light pulses through the air using infrared lasers. Requiring line of site, free space optics (FSO) provides point-to-point and point-to-multipoint transmission without requiring a government license for use of the spectrum.

Because weather conditions such as fog can reflect light signals, redundant paths can be created by sending multiple signals to reflectors on different buildings. Transmitters with multiple beams are also used to provide greater reliability.

In time, free space optics is expected to be used for short distances within high-speed buses in computers and switches, perhaps even within the chip itself. See visible light communication.

Multi-Beam FSO Transceiver

This FlightSpectrum unit transmits 1.25 Gbps up to 3,000 meters and sends multiple beams for greater reliability. Approximately 1x1x2 feet in size, it connects to single mode and multimode fiber. (Image courtesy of Lightpointe.)