Polarization Modulation in Quantum Dot Spin-VCSELs for Ultrafast Data Transmission

Quantum‐dot spin vertical‐cavity surface‐emitting lasers (VCSELs) are a relatively new addition to the spin‐VCSELs literature. The quantum‐dot active region, apart from the usual advantages carried by the quantum confinement in all three directions, offers additional degrees of freedom for the manipulation of the polarization of the emitted light. In, the present contribution, a detailed analysis on the key parameter optimization of optically pumped quantum‐dot spin‐VCSELs is presented. The influence of the spin polarization of the carriers on the polarization control is investigated over a large range of birefringence rate and spin‐relaxation rate values. Precise polarization control is shown in the results, as represented on maps in the plane of pump ellipticity versus birefringence rate. The trajectories on Poincaré sphere reveal a rich polarization behavior ranging from spin amplification to polarization chaos.