Unit 8. Lab 1. Fiber Optic Connector Assembly
The most critical part, the Cable and Fiber Preparation where the fiber is mounted, is the ferrule. The Ferrule is a long, thin cylinder with the fiber mounted in the center hole. The center hole is sized to match fiber's cladding diameter which is usually 125um. When fiber connector ferrules are made from several types of materials including ceramic(Zirconia), stainless steel and plastic. The ferrule's job is to center and align the fiber and protects it from mechanical damage. The end of fiber is at the end of the ferrule, where the fiber end is polished smooth either flat or with a curvature. The ferrule is mounted in the connector body and then the connector body is attached to the fiber optic cable structure. Finally, a strain-relief rubber boot protects the connector-cable junction.
Fiber optic connectors usually do not have the male-female polarity. Most fiber connectors are male only. Instead, fiber connectors mate to each other in fiber adapters, which are often called mating sleeves or coupling receptacles. Fiber optic adapters used to mate different connector types such as a FC connector to a SC connector are called hybrid adapters. Although this approach requires the use of separate adapters, it otherwise reduces fiber connector inventory requirements since now you need to stock one type of connector only. Another advantage is that fiber adapters can be designed to mate one type of connector to another, which is a big plus compared to electronic connectors. The fiber's plastic coating is stripped first before the fiber is inserted in the ferrule. The center hole through the ferrule is large enough to fit the

Fiber cladding (which is usually 125um after fiber coating stripped off) but tight enough to hold the fiber in a fixed position without any further moving.
Standard bore diameters are 126 +1/-0 um