Equivalent circuit model of quantum dot semiconductor optical amplifiers: dynamic behaviour and saturation properties

Abstract

In this paper, we derive an equivalent circuit model for a quantum dot semiconductor optical amplifier (QD-SOA) by employing rate equations for electronic transitions between the QD's levels and also the optical power propagation. The different parts of the equivalent circuits interact together to represent the gain recovery process, saturation properties and chirp behaviour in both linear and nonlinear operation regimes of the QD-SOA. The equivalent circuits are then used for SPICE simulation. We have also applied a control pulse to decrease the gain recovery time using the cross-gain modulation (XGM) effect, and the equivalent circuit of this source has been discussed. The Tb s−1 operation capability can be illustrated using this approach. We have shown that SPICE simulation results agree well with the full numerically calculated results.