Optical communication


Optical communication

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.

Contents

Forms of optical communication

Naval signal

There are many forms of non-technological optical communication, including body language and sign language.

Techniques such as semaphore lines, ship flags, smoke signals, and beacon fires were the earliest form of technological optical communication.

The heliograph uses a mirror to reflect sunlight to a distant observer. By moving the mirror the distant observer sees flashes of light that can be used to send a prearranged signaling code. Navy ships often use a signal lamp to signal in Morse code in a similar way.

Distress flares are used by mariners in emergencies, while lighthouses and navigation lights are used to communicate navigation hazards.

Aircraft use the landing lights at airports to land safely, especially at night. Aircraft landing on an aircraft carrier use a similar system to land correctly on the carrier deck. The light systems communicate the correct position of the aircraft relative to the best landing glideslope. Also, many control towers still have an Aldis lamp to communicate with planes whose radio failed.

Optical fiber is the most common medium for modern digital optical communication.

Free-space optical communication is also used today in a variety of applications.

Optical fiber communication

Main article: Fiber-optic communication.

Optical fiber is the most common type of channel for optical communications, however, other types of optical waveguides are used within computers or communications gear, and have even formed the channel of very short distance (e.g. chip-to-chip, intra-chip) links in laboratory trials. The transmitters in optical fiber links are generally light-emitting diodes (LEDs) or laser diodes. Infrared light, rather than visible light is used more commonly, because optical fibers transmit infrared wavelengths with less attenuation and dispersion. The signal encoding is typically simple intensity modulation, although historically optical phase and frequency modulation have been demonstrated in the lab. The need for periodic signal regeneration was largely superseded by the introduction of the erbium-doped fiber amplifier, which extended link distances at significantly lower cost.

Free-space optical communication

Main article: Free space optical communication.

Free Space Optics (FSO) systems are generally employed for 'last mile' communications and can function over distances of several kilometers as long as there is a clear line of sight between the source and the destination, and the optical receiver can reliably decode the transmitted information. IrDA is an example of low-data-rate, short distance free-space optical communications using LEDs.

Other free-space systems can provide high-data-rate, long-range links using small, low-mass, low-power-consumption subsystems.[1]

See also

References

  1. ^ Wilson, K.. "Recent Development in High-Data Rate Optical Communications at JPL". Jet Propulsion Laboratory. NASA Technical Reports Server. http://hdl.handle.net/2014/18156. Retrieved 4 October 2011. 



Wikimedia Foundation. 2010.

Look at other dictionaries:

  • optical communication — optinis ryšys statusas T sritis automatika atitikmenys: angl. optical communication vok. optische Kopplung, f; optische Nachrichtenübertragung, f rus. оптическая связь, f pranc. communication optique, m …   Automatikos terminų žodynas

  • optical communication channel — optinis ryšio kanalas statusas T sritis automatika atitikmenys: angl. optical communication channel vok. optischer Übertragungskanal, m; optischer Nachrichtenkanal, m rus. оптический информационный канал, m; оптический канал связи, m pranc. canal …   Automatikos terminų žodynas

  • optical communication receiver — optinio ryšio imtuvas statusas T sritis radioelektronika atitikmenys: angl. optical communication receiver vok. optischer Verbindungsempfänger, m rus. приёмник оптической связи, m pranc. récepteur de communication optique, m …   Radioelektronikos terminų žodynas

  • Free space optical communication — In telecommunications, Free Space Optics (FSO) is an optical communication technology that uses light propagating in free space to transmit data between two points. The technology is useful where the physical connection by the means of fibre… …   Wikipedia

  • Optical wireless — is the combined use of optical (optical fibre) and wireless (radio frequency) communication to provide telecommunication to clusters of end points which are geographically distant. The high capacity optical fibre is used to span the longest… …   Wikipedia

  • Optical Carrier transmission rates — are a standardized set of specifications of transmission bandwidth for digital signals that can be carried on Synchronous Optical Networking (SONET) fiber optic networks.[1] Transmission rates are defined by rate of the bitstream of the digital… …   Wikipedia

  • Optical interconnect — is a way of communication by optical cables.[1] Compared to traditional cables, optical wires are capable of a much higher bandwidth, from 10 Gb/s up to 100 Gb/s.[2] The technology is currently being introduced as a way to link computers to… …   Wikipedia

  • Optical networking — can refer to: Optical communication Fiber optic communication Synchronous optical networking Optical Transport Network (OTN) Passive optical network This disambiguation page lists articles associated with the same title. If an …   Wikipedia

  • Communication physics — is one of the applied branches of physics. It deals with various kinds of communication systems Electronic communication Optical communication Computer communication Telephone Telegraph Radio Television Mobile phone communication Nanoscale… …   Wikipedia

  • Optical fiber — A bundle of optical fibers A TOSLINK fiber optic audio c …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.