Fiber optic fiber termination

Fiber optic joints or terminations are made two ways: 1)  splices which create a permanent joint between the two fibers or 2) connectors that mate two fibers to create a temporary joint and/or connect the fiber to a piece of network gear. Either joining method must have three primary characteristics for good optical performance: low loss, minimal reflectance and high mechanical strength.  Terminations must also be of the right style to be compatible to the equipment involved and be protected against the environment in which they are installed.
Splices are considered permanent joints and are used for joining most outside plant cables. Fusion splicing is most widely used as it provides for the lowest loss and least reflectance, as well as providing the most reliable joint. Virtually all singlemode splices are fusion. Mechanical splicing is used for temporary restoration and for most multimode splicing.
Connectors are used for terminations, that is the ends of the fibers where they connect to equipment or to patch panels where fiber routing can be changed by patching different fibers together. Different connectors and termination procedures are used for multimode and singlemode fibers. Multimode fibers are relatively easy to terminate, so field termination is generally done by installing connectors directly on tight buffered fibers using the procedures outlined below. Most field singlemode terminations are made by splicing a factory-made pigtail onto the installed cable rather than terminating the fiber directly as is commonly done with multimode fiber. Singlemode terminations require extreme care in assembly, especially polishing, to get good performance (low loss and reflectance), so they are usually done in a clean manufacturing facility using heat-cured epoxy and machine polishing.