Polarization dynamics of vertical-cavity surface-emitting lasers: impact of optical feedback and optical injection

Vertical-Cavity Surface-Emitting Lasers (VCSELs) present significant advantages over their edge-emitting counterparts, such as single longitudinal mode emission, low cost, circular output beam, and easy fabrication in two-dimensional arrays. However, due to the surface emission and cylindrical symmetry VCSELs lack strong polarization anisotropy and may undergo polarization switching. This provides new features to the rich nonlinear dynamics observed in semiconductor lasers under external perturbation. In this paper we present our recent results on nonlinear polarization dynamics of VCSELs for the case of optical injection and optical feedback.