Theory of Pattern-free Pulse-Train amplification in Reduced Dimensional Semiconductor Optical Amplifiers

摘要

It was previously predicted that it should be possible to achieve pattern-free amplification at large pump current densities in a QD SOA. The key points to achieve this are to reach a constant maximum gain level due to a complete population inversion of the lowest QD levels, and also because the modal gain is lower in a QD SOA compared to a QW or bulk SOA. Initial calculations have been presented here to investigate the influence of the slower gain saturation typically observed in realistic QD structures. We conclude that the slower saturation does reduce the highest speeds at which pattern-effect-free operation can be achieved for a given drive current but that QD SOAs retain significant promise for pattern-effect-free pulse amplification, as well as for cross-gain and for cross phase modulation.