Free-space optical communication
Free-space optical communication (FSO) is an optical communication technology that uses light propagating in free space to wirelessly transmit data for telecommunications or computer networking. "Free space" means air, outer space, vacuum, or something similar. This contrasts with using solids such as optical fiber cable.
This article is about optical communication over long distances. For short- to medium-range communication, see Optical wireless communications.The technology is useful where the physical connections are impractical due to high costs or other considerations.
received approximately $575 million in funding from investors such as Softbank, Mobius Venture Capital and Oakhill Venture Partners. AT&T and Lucent backed this attempt.[17][18] The work ultimately failed, and the company was purchased in 2004 for $52 million (excluding warrants and options) by Falls Church, Va.-based YDI, effective June 22, 2004, and used the name Terabeam for the new entity. On September 4, 2007, Terabeam (then headquartered in San Jose, California) announced it would change its name to Proxim Wireless Corporation, and change its NASDAQ stock symbol from TRBM to PRXM.[19]
Terabeam
AirFiber received $96.1 million in funding, and never solved the weather issue. They sold out to MRV communications in 2003, and MRV sold their FSO units until 2012 when the end-of-life was abruptly announced for the Terescope series.
[20]
LightPointe Communications received $76 million in start-up funds, and eventually reorganized to sell hybrid FSO-RF units to overcome the weather-based challenges.
[21]
The Maxima Corporation published its operating theory in ,[22] and received $9 million in funding before permanently shutting down. No known spin-off or purchase followed this effort.
Science
Wireless Excellence developed and launched CableFree UNITY solutions that combine FSO with millimeter wave and radio technologies to extend distance, capacity and availability, with a goal of making FSO a more useful and practical technology.
[23]
To cross a public road or other barriers which the sender and receiver do not own
Speedy service delivery of high-bandwidth access to networks
optical fiber
Converged voice-data connection
Temporary network installation (for events or other purposes)
Reestablish high-speed connection quickly ()
disaster recovery
As a safety add-on for important fiber connections (redundancy)
For inter- and intra-chip communication
[44]
Atomic line filter#Laser tracking and communication
Extremely high frequency
KORUZA
Laser safety
Mie scattering
Modulating retro-reflector
N-slit interferometer
Optical window
Radio window
Rayleigh scattering
Free-space path loss
Christos Kontogeorgakis (May 1997). (Thesis). Virginia Polytechnic Institute and State University. hdl:10919/37049. Master's Thesis
Millimeter Through Visible Frequency Waves Through Aerosols-Particle Modeling, Reflectivity and Attenuation
Heinz Willebrand & Baksheesh Ghuman (December 2001). . SAMS. Archived from the original on 2012-06-22.
Free Space Optics: Enabling Optical Connectivity in Today's Networks
Moll, Florian (December 2013). "Free-space laser system for secure air-to-ground quantum communications". SPIE Newsroom. :10.1117/2.1201311.005189.
doi
Free Space Optics on COST297 for HAPs
Explanation of Fresnel zones in microwave and optical links
March 2014 NASA's Optical Payload for Lasercomm Science demonstration mission to the ISS
International Space Station to Beam Video Via Laser Back to Earth
(with python examples).