Optical add-drop multiplexer

Optical add-drop multiplexer
Optical add-drop multiplexer, using a fiber Bragg grating and two circulators.

An optical add-drop multiplexer (OADM) is a device used in wavelength-division multiplexing systems for multiplexing and routing different channels of light into or out of a single mode fiber (SMF). This is a type of optical node, which is generally used for the construction of optical telecommunications networks. "Add" and "drop" here refer to the capability of the device to add one or more new wavelength channels to an existing multi-wavelength WDM signal, and/or to drop (remove) one or more channels, passing those signals to another network path. An OADM may be considered to be a specific type of optical cross-connect.

A traditional OADM consists of three stages: an optical demultiplexer, an optical multiplexer, and between them a method of reconfiguring the paths between the optical demultiplexer, the optical multiplexer and a set of ports for adding and dropping signals. The optical demultiplexer separates wavelengths in an input fiber onto ports. The reconfiguration can be achieved by a fiber patch panel or by optical switches which direct the wavelengths to the optical multiplexer or to drop ports. The optical multiplexer multiplexes the wavelength channels that are to continue on from demultipexer ports with those from the add ports, onto a single output fiber.

All the light paths that directly pass an OADM are termed cut-through lightpaths, while those that are added or dropped at the OADM node are termed added/dropped lightpaths. An OADM with remotely reconfigurable optical switches (for example 1×2) in the middle stage is called a reconfigurable OADM (ROADM). Ones without this feature are known as fixed OADMs. While the term OADM applies to both types, it is often used interchangeably with ROADM.

Physically, there are several ways to realize an OADM. There are a variety of demultiplexer and multiplexer technologies including thin film filters, fiber Bragg gratings with optical circulators, free space grating devices and integrated planar Arrayed waveguide gratings. The switching or reconfiguration functions range from the manual fiber patch panel to a variety of switching technologies including MEMS, Liquid crystal and thermo optic switches in planar waveguide circuits.

Although both have add/drop functionality, OADMs are distinct from add-drop multiplexers. The former function in the photonic domain under wavelength-division multiplexing, while the latter are implicitly considered to function in the traditional SONET/SDH networks.

See also

References


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать курсовую

Look at other dictionaries:

  • Reconfigurable optical add-drop multiplexer — A reconfigurable optical add drop multiplexer (ROADM) is a form of optical add drop multiplexer that adds the ability to remotely switch traffic from a WDM system at the wavelength layer. This allows individual wavelengths carrying data channels… …   Wikipedia

  • Reconfigurable Optical Add Drop Multiplexer — ROADM est l acronyme de l expression anglaise Reconfigurable Optical Add Drop Multiplexer, ou « multiplexeur optique d insertion extraction reconfigurable », selon la traduction homologuée par l Office québécois de la langue française.… …   Wikipédia en Français

  • Add-drop multiplexer — An add drop multiplexer (ADM) is an important element of an optical fiber network. A multiplexer combines, or multiplexes, several lower bandwidth streams of data into a single beam of light. An add drop multiplexer also has the capability to add …   Wikipedia

  • Optical mesh network — Transport network based on SONET/SDH ring architecture Optical mesh networks are a type of telecommunications network. Transport networks, the underlying optical fiber based layer of telecommunications networks, have evolved from DCS (Digital… …   Wikipedia

  • Optical Society of America — The Optical Society of America (OSA) is a scientific society dedicated to advancing the study of light optics and photonics in theory and application, by means of worldwide research, scientific publishing, conferences and exhibitions, partnership …   Wikipedia

  • Optical cross-connect — An optical cross connect (OXC) is a device used by telecommunications carriers to switch high speed optical signals in a fiber optic network, such as an optical mesh network. There are several ways to realize an OXC: Opaque OXCs (electronic… …   Wikipedia

  • Optical interleaver — Illustration of the function of an optical interleaver and de interleaver An optical interleaver is a 3 port passive fiber optic device that is used to combine two sets of dense wavelength division multiplexing (DWDM) channels (odd and even… …   Wikipedia

  • Optical Transport Network — Das optische Transportnetz (OTN, engl.: optical transport network) ist eine von der ITU im Standard G.709 standardisierte Technologie für ein Telekommunikationsnetz, mit dem Netzbetreiber mittels eines Transportdienstes Nutzdaten übertragen. Die… …   Deutsch Wikipedia

  • Optical Frequency Division Multiplexing — Multiplexverfahren (lat. multiplex „vielfach, vielfältig“) sind Methoden zur Signal und Nachrichtenübertragung, bei denen mehrere Signale zusammengefasst (gebündelt) und simultan über ein Medium (Leitung, Kabel oder Funkstrecke) übertragen werden …   Deutsch Wikipedia

  • Crossconnect-Multiplexer — Die Synchronous Digital Hierarchy (SDH) ist eine der Multiplextechniken im Bereich der Telekommunikation, die das Zusammenfassen von niederratigen Datenströmen zu einem hochratigen Datenstrom erlaubt. Das gesamte Netz ist dabei synchron.… …   Deutsch Wikipedia

Share the article and excerpts

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