2 - Optical Fiber, Cables, and Connectors

Abstract

This chapter gives an overview of optical fiber, cables, and connectors. Light is most accurately described as a vectorial electromagnetic wave. In the case of optical fibers used for tele- and data communication, it is sufficient to use a scalar wave approximation to describe light propagation in single mode fibers and a ray approximation for light propagation in multimode fibers. Attenuation is an important factor in designing effective long-distance fiber-optic networks. In addition, dispersion occurs because different wavelengths experience different propagation constants, and therefore travel with different velocities, causing a longer temporal pulse at the end of the fiber. For tele- and data communication fibers, fused silica glass is the preferred material. An optical fiber is very brittle and susceptible to chemical degradation, so it is important to protect the optical performance. Two common types of fiber-optic cable construction are used for protection. It is important to be able to easily reconfigure communication links for cost and performance optimization, to replace link subunits, and to relocate equipment. To do this, connectors are a key component in the vast majority of optical links.