Editing Single-mode optical fiber (section)

==Connectors==
[[Optical fiber connector]]s are used to join optical fibers where a connect/disconnect capability is required. The basic connector unit is a connector assembly. A connector assembly consists of an adapter and two connector plugs. 
Due to the sophisticated polishing and tuning procedures that may be incorporated into optical connector manufacturing, connectors are generally assembled onto optical fiber in a supplier's manufacturing facility. However, the assembly and
polishing operations involved can be performed in the field, for example to make cross-connect jumpers to size.

Optical fiber connectors are used in telephone company central offices, at installations on customer premises, and in outside plant applications. Their uses include:
* Making the connection between equipment and the telephone plant in the central office
* Connecting fibers to remote and outside plant electronics such as optical network units (ONUs) and digital loop carrier (DLC) systems
* Optical cross connects in the central office
* Patching panels in the outside plant to provide architectural flexibility and to interconnect fibers belonging to different service providers
* Connecting couplers, splitters, and wavelength-division multiplexers (WDMs) to optical fibers
* Connecting optical test equipment to fibers for testing and maintenance.

Outside plant applications may involve locating connectors underground in subsurface enclosures that may be subject to flooding, on outdoor walls, or on utility poles. The closures that enclose them may be hermetic, or may be “free-breathing.” Hermetic closures will prevent the connectors within being subjected to temperature swings unless they are breached. Free-breathing enclosures will subject them to temperature and humidity swings, and possibly to condensation and biological action from airborne bacteria, insects, etc. Connectors in the underground plant may be subjected to groundwater immersion if the closures containing them are breached or improperly assembled.

The latest industry requirements for optical fiber connectors are in [[Telcordia]] [http://telecom-info.njdepot.ericsson.net/site-cgi/ido/docs.cgi?ID=SEARCH&DOCUMENT=GR-326& GR-326], ''Generic Requirements for Single-Mode Optical Connectors and Jumper Assemblies''.

A ''multi-fiber'' optical connector is designed to simultaneously join multiple optical fibers together, with each optical fiber being joined to only one other optical fiber.

The last part of the definition is included so as not to confuse multi-fiber connectors with a branching component, such as a coupler. The latter joins one optical fiber to two or more other optical fibers.

Multi-fiber optical connectors are designed to be used wherever quick and/or repetitive connects and disconnects of a group of fibers are needed. Applications include telecommunications companies’ central offices (COs), installations on customer premises, and outside plant (OSP) applications.

The multi-fiber optical connector can be used in the creation of a low-cost switch for use in fiber optical testing. Another application is in cables delivered to a user with pre-terminated multi-fiber jumpers. This would reduce the need for field splicing, which could greatly reduce the number of hours necessary for placing an [[optical fiber cable]] in a telecommunications network. This, in turn, would result in savings for the installer of such cable.

Industry requirements for multi-fiber optical connectors are covered in [http://telecom-info.njdepot.ericsson.net/site-cgi/ido/docs.cgi?ID=SEARCH&DOCUMENT=GR-1435& GR-1435], ''Generic Requirements for Multi-Fiber Optical Connectors''.