TABLE OF CONTENTS Optical fibers provide the ability to use optics instead of metallic media to achieve numerous useful end results. In all cases the fiber requires an optical source and detector and cannot be used alone. As a result, optical fiber applications must always be considered in combination with their required E/O and O/E converters. This chapter looks at modern optical fiber telecommunications systems and the relationships between the source, fiber, and detector.
A general block diagram of a uni-directional optical fiber telecommunications system is shown in Figure 7 1. The optical source, LED or laser, is driven by the electrical baseband signal. Many different types of baseband signals are possible. The electrical section of the transmitter is designed specifically to accommodate the expected baseband signal and drive the chosen type of optical source. The electrical and optical sections of the transmitter are designed and built as one unit. There is not a one-size-fits-all transmitter available. Similarly, the receiver s electrical section is matched to the baseband signal and the chosen photodetector, PIN diode or APD. The transmitter and receiver are often combined in one unit, called a transceiver.
Terminal locations have a number of optical components. If only a simple link is used for the system, there might only be connectors, splices and an optical patch panel. Optical fibers now are used in complex optical networks that might require the addition of optical switches, multiplexers, demultiplexers, filters, waveguide converters, and routers at terminal locations. The ...
