Free-space Optical (FSO) Photodetectors

Optical technologies over the past few decades have evolved with motivations based upon fibre optic trasmission media. The high-speed benefits of optical transmission and reception have allowed for terabit/sec data rates, although the unidirectional nature of optical fibres have inherent limitations for communication systems desiring omnidirectional optical wireless links.

The IOL develops new high-speed optical communication devices for the free-space environment. These micro-devices can be deployed as Smart Dust elements in omnidirectional optical wireless communication networks. The elements establish bi-directional optical links and encode modulated signals for data transmission and positioning. Corner-cube retrodetectors reflect a portion of incident light back to their respective sources for FSO uplink communication, while simultaneously sampling incoming optical downlink data. At the same time, differential signals from these retrodetectors can be used to triangulate the incident angle of arrival for positioning applications. Efforts are underway to impliment ultrafast optical versions of these omnidirectional FSO photodetectors.