1. Introduction and Overview

By many accounts, the field of electro-optics is progressing at a faster pace than the field of computer electronics. For example, when we hear of breakthroughs in storage capacities and playback speeds, we know that optical media provide the best performance. With this in mind, anyone new to this field can easily become discouraged when trying to determine, for example, how the compact disc player stores and plays back this information. As with any other area of science, learning the basics will provide a good start to understanding a seemingly complex application. All optoelectronic devices such as diode lasers, LEDs, and photodiodes operate on the physical principle of the interaction of radiation and matter. This basic quantum process is responsible for the production of electromagnetic radiation.

So, why has the use of optoelectronic devices skyrocketed in recent years? One answer that quickly comes to mind is speed. As anyone who works with a personal computer knows, a machine built just a few years ago will have trouble running the latest software applications. The computer must have the ability to handle the increased information throughput that allows for the efficient transfer of electrical signals. Unfortunately, limits exist to how fast these signals can be transmitted in copper wire. As the frequency of the electronic signal increases, its ability to travel through a conductor decreases. This limitation is known as the skin effect. The consequence of the skin effect requires signals with oscillation frequencies in excess of about 100 Megahertz to be transmitted in coaxial cable. Electron flow through a conductor is not the only way to transmit information.