Feasibility study of an optical bus utilizing InGaAsP vertical transmission optical amplifiers

An optical bus utilizing vertical transmission optical amplifiers with a 3-dB gain could be effective in minimizing interboard connection delay time in massively parallel computers. In this study, the performance of such an optical bus was theoretically investigated from the viewpoints of noise and gain saturation. It is possible to achieve low-power operation in a Fabry-Perot type amplifier with a facet reflectivity of 0.8. By introducing asymmetry into facet reflectivities, the reflection gain, which disturbs stable operation, can be effectively suppressed without a serious increase in operation current. Our study predicted that it will be possible to connect more than 100 boards without electrical repeaters.