ABSTRACT
This chapter presents a review of fiber optics technology in the two main applications that are relevant for telecommunication networks: transmission fibers and optical fiber amplifiers. The ultimate role of the telecommunication network is to deliver services based on the network capability of transmitting the information generated in one place to faraway places. An optical fiber is a circular dielectric glass waveguide that has a wide number of applications in telecommunications, in sensor systems and in medicine. All the telecommunication cables include single-mode fibers, even if multimode fiber cables and even mixed fiber cables are used for other applications or for compatibility with legacy systems generally in the access area. Photonic crystal fibers (PCF) are another type of special fibers that could find wide application in future telecommunication system mainly in active and passive fiber devices. In general, regular structured fibers such as PCFs, have a cross section microstructured from one, two or more materials.
