| :: Choices of connectors | | | | provides mechanical support for fiber and |
| Over the years, a large variety of fiber optic | | | | connector handling. |
| connectors have been designed for most fiber | | | | :: Legacy Fiber Connector Types |
| optic installations. Lightwave equipment | | | | The following list shows the legacy connector |
| manufacturers have never standardized on any | | | | types that have been deployed in numerous fiber |
| one connector type, they actually provide a | | | | optic networks for many years. |
| selection of connectors for their equipment | | | | ST Connector |
| interface. | | | | ST connector was once the most popular fiber |
| It is very important to choose the fiber | | | | connector. It was well-liked for both single mode |
| connector type for your applications. You should | | | | and multimode fiber connections. The average |
| maintain a connector standard throughout a fiber | | | | insertion loss for a ST connector is about 0.5dB. |
| optic project. | | | | ST connector has a twist-on locking mechanism |
| :: The components of a fiber connector | | | | which is not susceptible to loosening in vibrating |
| For most fiber optic connectors, the major | | | | environment. It is most often used in LAN |
| components are ferrule, connector body, | | | | networks. |
| connector cap and strain-relief boot. | | | | FC Connector |
| Ferrule | | | | FC connector is popular for single mode |
| The ferrule is the center part of the connector. It | | | | applications. It has the lowest insertion loss and |
| contains the optical fiber in a center hole. Ferrule | | | | the best repeatability. It has a thread-on locking |
| can be made from ceramic (Zirconia), stainless | | | | mechanism. |
| steel or composite material. | | | | SMA connector |
| Ceramic ferrule is the most popular material since | | | | SMA connector is a pretty old connector type |
| it has stable temperature characteristics. The | | | | which is mostly used for multimode applications. |
| most common ceramic is Zirconia which is a white | | | | Today it is still being using on medical equipment. |
| hard ceramic material. Ceramic ferrule is used for | | | | There are two types of SMA connectors on the |
| both single mode and multimode connectors. It | | | | market: SMA 905 and SMA 906. The only |
| offers the lowest insertion loss and the best | | | | difference between them is that SMA 906 has a |
| repeatability. | | | | straight ferrule while SMA 905 has a step-down |
| Connector Body | | | | ferrule. |
| Fiber optic connector body can be steel or plastic. | | | | D4 Connector |
| The body design differs from connector to | | | | The NEC D4 was probably the first connector to |
| connector. The connector body provides the | | | | use ceramic or hybrid ceramic/stainless steel |
| mechanism to hold the ferrule and other parts | | | | ferrules. It uses a smaller ferrule than SCs or FCs. |
| together. It also provides the locking mechanism | | | | It was widely used in telco networks in the 80s |
| for connector mating. The most common locking | | | | to early 90s and some may still be in use. |
| mechanisms are push-pull, snap-in, thread on and | | | | FDDI connector |
| twist-on. | | | | Besides the SC Duplex, you may occasionally see |
| Connector Cap | | | | the FDDI duplex connectors which mate to their |
| Connector cap often has the same material as | | | | specific networks. They are generally used to |
| the body: either steel or plastic. The cap can be | | | | connect to the equipment from a wall outlet, but |
| screw on, twist lock or snap-on for connector | | | | the rest of the network will have ST or SC |
| mating. | | | | connectors. Since they both use 2.5 mm ferrules, |
| Strain-relief Boot | | | | they can be mated to SC or ST connectors with |
| Strain-relief boot is the part connecting the | | | | adapters. |
| connector body and the fiber cable. It is often | | | | Biconic Connector |
| made from rubber. Although it looks minimal, it is | | | | Biconic connector's yellow body indicating a SM |
| actually one of the most critical parts in a | | | | version - mutlimode versions were usually black. |
| connector. It provides strain relief on the optical | | | | Biconic connector was developed by a team led |
| fiber to prevent micro-bending, breakage and | | | | by Jack Cook at Bell Labs in Murray Hill, NJ. |