Optical fiber connector

Optical fiber connectors are categorized into single-mode and multimode types based on their distinct characteristics.

However, the assembly and polishing operations involved can be performed in the field, for example, to terminate long runs at a patch panel.

The resulting glass-to-glass or plastic-to-plastic contact eliminates signal losses that would be caused by an air gap between the joined fibers.

In many data center applications, small (e.g., LC) and multi-fiber (e.g., MTP/MPO) connectors have replaced larger, older styles (e.g., SC), allowing more fiber ports per unit of rack space.

[4] Outside plant applications may require connectors be located underground, or on outdoor walls or utility poles.

In such settings, protective enclosures are often used, and fall into two broad categories: hermetic (sealed) and free-breathing.

Hermetic cases prevent entry of moisture and air but, lacking ventilation, can become hot if exposed to sunlight or other sources of heat.

Free-breathing enclosures, on the other hand, allow ventilation, but can also admit moisture, insects and airborne contaminants.

Selection of the correct housing depends on the cable and connector type, the location, and environmental factors.

Modern connectors typically use a physical contact polish on the fiber and ferrule end.

Higher grades of polish give less insertion loss and lower back reflection.

Generally angle-polished connectors have higher insertion loss than good quality straight physical contact ones.

Field-mountable optical fiber connectors are used for field restoration work and to eliminate the need to stock jumper cords of various sizes.

A profiling system may be used to ensure the overall polished shape is correct, and a good quality optical microscope to check for blemishes.