Optical fibers are one of the most powerful tools in data transferring. An optical fiber consists of a core, cladding, Kevlar layer, ferrule and connector. The core includes a very fine continuous glass thread with a thickness like human hair which is responsible for transmitting light pulses. The core is surrounded by a transparent cladding material which can be an acrylate or polyamide polymer and reflect the light into the core by the total internal reflection phenomenon. Kevlar fiber due to its high tensile strength is usually used as a protecting layer. The outer layer of the cable is usually a sheath of PVC. Environmental condition is the key factor to choose the material for the sheath. The following picture shows different parts of an optical fiber. Optical fibers are connected to terminal equipment by optical fiber connectors.

These fibers have advantages, including reducing signal loss at the distance unit, higher capacity, lower size, higher safety, etc.

Optical fibers can carry signals in different modes, the pathway that light follows, and is divided into single and multi-mode. Single mode fibers have a thin core diameter and are used for most communication links longer than 1,000 meters. Computer networks, Tv, medical scans, military equipment are some common applications of these fibers.