TABLE OF CONTENTS In this chapter we will focus on the manner in which LEDs are being used to transmit information. Although most readers will be aware of the role of lasers in transmitting information via fiber-optic cable, to paraphrase the late Rodney Dangerfield, "LEDs get no respect" yet play an important role in the wonderful world of modern communications.
From infrared (IR) remote control to high-speed Ethernet networking, LEDs provide a low-cost, viable transmission capability that is the subject of this chapter. As we proceed through this chapter, we will focus attention on the manner in which LEDs are being used in a variety of communication applications. Because readers have different backgrounds, prior to explaining the use of LEDs in a particular communications application, the underlying technology or set of technologies associated with a particular communications method will be explained. Hopefully, by the end of this chapter, readers will have a new appreciation for LEDs and, unlike the late Rodney Dangerfield, you will also have a new respect for the use of LEDs in different types of applications that require a communications capability.
Perhaps one of the most important inventions of the 20th century for operator convenience was the remote control. First developed as a mechanism to change television channels on black and white TVs, today there are literally hundreds of different types of remote controls. For example, in addition to controlling televisions, VCRs, DVD players, and audio components, one can also purchase fans, garage doors,...
