Role of materials in lightwave communications

The spectacular growth of transmission capacity in communications in recent years rivals even that of the growth of computing power. This is made possible in lightwave communications by using appropriately tailored silica fibers with minimum attenuation and dispersion characteristics and by the use of advanced semiconductor materials for light emitting diodes, lasers and detectors. Compound semiconductors such as InGaAsP epitaxically grown on InP substrates have provided the most reliable light emitters and erbium doped silica fibers an used as optical amplifiers avoiding frequent changes of optical signals to electrical ones far amplification. The availability of such optical amplifiers has increased the distance and range of such communications, and also the bandwidth through wave-division multiplexing. This review discusses the materials issues of light wave communications including the fabrication of devices and also their evaluation.