Gain and Phase Dynamics of QD-VCSOA Under Electrical and Optical Pumping

The effect of pumping methods on the gain and phase dynamics of quantum-dot vertical cavity semiconductor optical amplifier is investigated. The gain and phase recovery time is considered at the ground state transition wavelength. By including the effect of the excited state and wetting layer on the refractive index change, it is shown that under electrical pumping, the better gain dynamics is achieved compared to the optical pumping scheme. However, the phase recovery time can be accelerated by optical pumping. These behaviors result from the different mechanisms of population inversion in these two pumping methods.