Optical communication

The science and technology of communication at a distance by electronic transmission of impulses, as by telegraph, cable, telephone, radio, or television is known as telecommunication. Optical communication is any form of telecommunication that uses light as the transmission medium. An optical communication system consists of a transmitter, which encodes a message into an optical signal, a channel, which carries the signal to its destination, and a receiver, which reproduces the message from the received optical signal. Optical fiber is the most universal type of channel for optical communications; still other types of optical waveguides are used within communications kit, and have even formed the channel of very short distance (e.g. chip-to-chip) ties in laboratory testing. The transmitters in optical fiber linkages are commonly light-emitting diodes (LEDs) or laser diodes. Infrared light, rather than visible light is utilized more frequently, because optical fibers transmit infrared wavelengths with less attenuation and dispersion. LEDs are mainly restricted to low data rates, up to about 100 Megabits per second (Mb/s). Lasers are exploited for higher data rates. These devices are often directly transformed which means that the light output is controlled by a current applied directly to the device. A group of theoretical physicists at the University of Arkansas has showed that under applied voltages, thin films composed of ferroelectric materials form "nanobubbles". They have the potential to store lots of information in a tiny space. This could force technologies from computers and portable electronics such as cell phones and MP3 players, to radio frequency identification devices. Novel optical properties can be created by mixing of nano particles of lead selenide (PbSe) and iron oxide (FeO).