Overview

Most optical telecom systems rely on fibers. But they rely on much more. The fibers themselves convey the light, but its creation, switching, detection, and management require a number of other components, such as those described in this chapter.

Among the topics discussed here are the components that act as the "glue" in these systems. For example, we discuss switches, their performance as a function of bandwidth, and their isolation performance. Similarly, we offer some insight into the operation of Benes and Clos switch architectures and their operation.

The devices covered in this chapter include common network components such as high-speed detectors (or receivers), high-speed erbium- doped fiber amplifiers (EDFAs), and switches. Although fast, modulated laser transmitters qualify as network components, we found enough related rules to justify creating a separate chapter dealing with them.

Not all of the rules are about specific elements; rather the rules define how performance features of those elements interact to define system performance. For example, we have included several rules that relate to the fundamental performance limits of switches and other components, including bandwidth, rise time, switching speed, channel-to-channel isolation, and noise performance. A particularly useful rule provides a quick way to determine the relative importance of shot noise and Johnson noise.

EDFAs receive considerable attention in this chapter. The authors recognize that many of the rules that are included here might have also been placed in the optical fiber chapter but, for a number of reasons, we have found it useful to...