Optical Fiber and Cables

Zusammenfassung

This chapter gives an overview and introduces application scenarios for optical fibers and cables in optical communications. The use of single-mode optical fibers for both short-reach and long-haul applications is growing due to continually increasing demand for higher bandwidth optical communication systems. To better understand fiber-based optical communications the chapter first focuses on the design of the single-mode fiber while the latter half focuses on the design of optical fiber cable. A wide variety of optical fiber cables have been designed and installed to meet the needs of various applications and this chapter reviews the many types of cables for fiber to the home as well as for datacenter connectivity.

We will start with a section showing the history of optical loss improvement. Then, the categories of optical fibers and their cross-sectional structure are explained. Next, the main features of single-mode fibers such as standard single-mode fiber (), bend-insensitive fiber (), cutoff-shifted fiber (), dispersion-shifted fiber (), and nonzero dispersion-shifted fiber () are summarized with their major optical characteristics. Then, features of each fiber type are explained. In particular, the cutting-edge application of low-loss fiber in ultralong-haul systems such as subsea systems are discussed and the importance of their system impact is also described. Thereafter, the key characteristics of multimode fiber are explained. In the final part of the optical fiber section, emerging fiber types are introduced such as fiber for space-division multiplexing () systems, for example multicore fiber, few-mode fiber, or coupled multicore fiber.

Thereafter, in the optical fiber cable section, we start with the classification of use cases such as indoor or outdoor cables and their features. Next, we introduce the optical fiber unit, a basic element used to bundle the fiber into cable, such as an optical fiber ribbon or loose tube. Following this we present many examples of optical fiber cables and their features, such as the slotted-rod cable, loose-tube cable, central-tube cable, layered fiber core cable, and direct-jacketed cable. Next, we present key considerations in optical cable design, such as fiber density, environment conditions, temperature change, water durability, biological attacks, and mechanical durability (bend, impact, torsion, crush). Finally, specific fiber cable use cases such as air-blown fiber cables and ultrahigh-density fiber cables for datacenter applications are introduced.

For more information about the basics of optical fibers and cables, we refer the reader to text books such as [2.1, 2.2]

• 1. D. Marcuse: Theory of Dielectric Optical Waveguides, Academic, New York, (1974)

• 2. Barry Elliott, Mike Gilmore: Fiber Optic Cabling, Elsevier Science, Netherlands, (2002)