Analysis of Quantum-Dot Spin-VCSELs

The derivation of a set of rate equations (REs) to describe optically pumped quantum-dot (QD) spin-injected vertical-cavity surface-emitting lasers (VCSELs) is presented based on a modified version of the spin-flip model. The approach includes capture of spin-up and spin-down electrons from the wetting layer into the ground state of the QD and also coupling between left- and right-circularly polarized fields caused by birefringence and dichroism. Numerical solutions of the REs are presented in the form of stability maps in the plane of pump polarization and total pump intensity; examples of calculated time series of the polarized field components are also given for specific cases of interest. The values of the spin-relaxation rate, the carrier capture rate, and the gain parameter are shown to have a significant effect on the dynamics of quantum-dot spin-VCSELs.