Optoelectronic guided-wave devices are used in many optical fiber communication and optoelectronic systems. In these systems optical and electrical signals are transmitted, received, multiplexed and converted by means of a variety of procedures. In guided-wave optoelectronic devices, laser radiation propagates in a waveguide and energy can be coupled effectively to and from single mode optical fibers. The properties of materials used to fabricate the waveguides have a profound effect on the phase, amplitude or directional variations of the optical waves used for the generation, modulation, switching, conversion, multiplexing, and detection of optical signals. The small lateral dimensions of the waveguide structures provide for efficient control of their optical properties by means of electrical voltages or currents. On the other hand, optical signals are converted back into electrical signals via detectors. Therefore, the electrical characteristics of these devices are as important as their optical properties. Devices may potentially be monolithically integrated optically on the same chip. This is called photonic integration. Optical components may also be integrated, monolithically, with electronic devices on the same chip. This is called optoelectronic integration. In earlier times, these were called integrated optical devices, as opposed to integrated electronic devices.

The manner in which different material properties affect the electrical characteristics as well as the propagation of optical signals in optoelectronic devices is of great importance. Also of considerable importance is the process of back and forth conversion of the electrical signals and of the optical signals.