GaAs Electroabsorption Avalanche Photodiode Waveguide Detectors.

摘要

There has been substantial recent interest in optical information transfer and processing systems because of their present and potential advantages over conventional electronic systems. These advantages include elimination of interference and ground-loop problems; achievement of wide bandwidths and increased security; and reductions in weight, size, and cost. To achieve these advantages, the realization of GaAs-based integrated optical circuits (IOCs) appears to be particularly promising since coherent light sources, optical detectors, modulators, and other active devices can potentially be integrated on the same substrate with passive devices. For wide bandwidth IOCs a critical component is the optical detector which must have internal gain to provide optimum sensitivity. This internal gain can be obtained in photovoltaic detectors by means of avalanche multiplication and wide-bandwidth, high-gain, low-noise avalanche photodiodes have been fabricated in GaAs. However, the response of these conventional GaAs avalanche photodiodes decreases rapidly for wavelengths longer than about 0.86 micron.