The fiber is composed of several layers of coaxial structure; the core, the cladding, the primary coating and the secondary coating. Concentricity describes how well oriented these layers are with respect to each other, and commonly we consider most important the concentricity of the core and cladding, as well as the cladding and coating of an optical fiber. Core-cladding concentricity is important because it is one of the principal factors determining the loss of a fusion splice or connector. Cladding-coating concentricity is important because it affects both the strength and coiling-characteristics of the fiber.
Related Terms: Cladding, Coating, Coating Concentricity, Core, End Face, Loss