Definition - What does Ferrule mean?
A ferrule is a component in fiber optics used for protecting and aligning the stripped fiber end. The fiber is inserted into the thin structure of the ferrule and provided with an adhesive to prevent contamination as well as to give it long-term mechanical strength. It is a major and costly component in a fiber connector, other ones being coupling mechanisms and the connector bodies. A poor connection can be the result of errors in length, hole centering or inside and outside diameter matching.
Techopedia explains Ferrule
Ferrule material is selected on a variety of factors such as durability of the material, cost, connector mating frequency, surface finish over time and the material's ability to retain end-face geometry. Ferrules can be manufactured from plastic, glass, metal or from any ceramic material. However, since ceramic bonds well to glass and is also environmentally stable due to the expansion coefficient being closer to glass fibers, ceramic is considered the best material for ferrule. The end face of the ferrule should be precisely shaped, as this helps in having the optimum physical contact between the each of the mated fiber pair. During the manufacture of fiber optic connectors, zirconia ceramics and composite plastic polymers are the two most common types used for ferrule materials. Ceramic materials provide the highest levels of dimensional control as well as high durability. They are suitable for all types of fiber applications including multi-mode and single mode. Composite plastic polymers are used in cases involving lower-cost ferrules.
Ferrule components are required not only for a good connection, but also for improving the quality of the connection established.