Fiber connector is used to join optical fibers where a connect/disconnect capability is required. Optical fibers terminate fiber-optic connections to fiber equipment or join two fiber connections without splicing. Fiber Optic Connector is an important components used in the fiber optic network. It is also the key part used in cat 7 cable and fiber optic pigtail. Fiber connectors are flexible, lower loss, lower cost, easier to terminate or solved some other perceived problem.
The basic connector unit is a connector assembly. Main components include a ferrule, sub-assembly body, cable, stress relief boot and connector housing. Modern connectors typically use a “physical contact” polish on the fiber and ferrule end. This is a slightly curved surface, so that when fibers are mated only the fiber cores touch, not the surrounding ferrules. Fiber-to-fiber interconnection can consist of a splice, a permanent connection, or a connector, which differs from the splice in its ability to be disconnected and reconnected.
Every fiber connection has two values:
Attenuation or insertion loss;
Reflection or return loss.
Optical fiber connectors were introduced with fiber optic technology in the 1980s. Fiber optic connector types are as various as the applications for which they were developed. Different connector types have different characteristics, different advantages and disadvantages, and different performance parameters. Typical connectors are rated for 500–1,000 mating cycles. The main differences among types of connectors are dimensions and methods of mechanical coupling. Generally, organizations will standardize on one kind of connector, depending on what equipment they commonly use. Different connectors are required for multimode, and for single-mode fibers. Hundreds of optical fiber connector types are available, but only a few represent the majority of the market. Widely used fiber connectors include the SC connector, LC connector, FC connector, ST connector, FDDI connector and E2000 connector.
LC connectors are sometimes called “Little Connectors”.
MT-RJ connectors look like a miniature 8P8C connector—commonly (but erroneously) referred to as RJ-45.
ST connectors refer to having a “straight tip”, as the sides of the ceramic (which has a lower temperature coefficient of expansion than metal) tip are parallel—as opposed to the predecessor bi-conic connector which aligned as two nesting ice cream cones would. Other mnemonics include “Set and Twist”, “Stab and Twist”, and “Single Twist”, referring to how it is inserted (the cable is pushed into the receiver, and the outer barrel is twisted to lock it into place). Also they are known as “Square Top” due to the flat end face.
SC connectors, being square, have a mnemonic of “Square Connector”, which some people believe to be the correct name, rather than the more official “Subscriber Connector”. Other terms often used for SC connectors are “Set and Click” or “Stab and Click”.
Features of good connector design:
Low insertion loss;
High return loss (low amounts of reflection at the interface);
Ease of installation;
Low environmental sensitivity;
Ease of use.