Phase Recovery Acceleration in Quantum-Dot Semiconductor Optical Amplifiers

In this paper, the acceleration of phase recovery in quantum-dot semiconductor optical amplifiers (QD-SOAs) is investigated by employing optical pumping (OP) scheme. For this purpose, the state space theory has been used to derive a dynamic model for the QD-SOA. The derived nonlinear state space model is employed to simulate the gain and phase responses of the device. For the first time, we show that OP can realize a shorter phase recovery time in comparison with electrical pumping (EP) scheme under equal pumping powers. We found that under OP, the contribution of slow phase recovery component induced by the slow carrier dynamics of the carrier reservoir is drastically reduced, and consequently, a fast phase response becomes feasible. Also, we found that under EP, the gain is recovered within a shorter time compared to OP scheme.