Optimal non-uniform current injection for quantum-dot semiconductor optical amplifiers

The influence of non-uniform current injection on the linear operation of a quantum dot semiconductor optical amplifier (QD-SOA) is investigated and optimal current injection profiles are determined. For this purpose, we have utilized some functions to generate various non-uniform current injection profiles. These profiles have been considered in our numerical calculations, where the rate equation model is employed to construct different characteristics of the QD-SOA. We have found that the gain, as well as the crosstalk of QD-SOA is closely related to the variance of the carrier density along the cavity. Simulation results show that non-uniform current injection can be used as a technique for gain enhancement as well as crosstalk suppression.