An optical fiber for the telecommunication is made of glass designed to guide light along its length by total internal reflection. The glass fiber has nominal diameter of 125μm (0.125mm) and covered with plastic jacket for protection to form 250μm or 900μm in diameter. The central part of the glass fiber which guides light is called “core” and the “cladding” around it has lower refractive index than the “core” to confine the guided light. Silica glass is fragile; therefore, it is covered with a protective jacket. There are three typical coatings for the optical fiber.
Primary coated fiber
This is covered with a UV cured-Acrylate to a diameter of nominal 0.25mm. Since it has an extraordinary small diameter, it has a superior capacity to fit a large number of fibers into a cable and is used widely.
Secondary jacketed fiber
Or tight or semi-tight buffered fiber. This is optical fiber covered with thermoplastic to a diameter of 0.9mm. Compared to 0.25mm fiber, it is stronger, easier to handle and is widely used in LAN wiring and other small fiber-count cable.
Ribbon fiber
Ribbon fiber provides an excellent way to boost the productivity of connector assemblies and facilitates mass fusion splicing for greater productivity. The ribbon is composed of 4,8 or 12 colored fibers for fiber counts as great as 1000. The fibers are encapsulated by a UV-acrylate material which can be easily removed with standard strippers for mass splicing or easily peeled apart for single fiber access. Ribbon can be spliced at once with mass –fusion splicer and easy for identification in high fibercount cable.
