Thorsten Ackemann

Broad-area vertical-cavity surface-emitting lasers (VCSELs) with feedback from an external cavity emerged as a highly controllable and versatile tool to investigate spatio-temporal self-organization. The external cavity provides natural means for control and to induce time-dependent behavior, which – via space-time analogy in systems with delay- can lead to quasi-3D spatial dynamics, in particular spatio-temporal solitons and potentially light bullets. The high circular symmetry of VCSELs also allows for the investigation of vectorial effects in light-matter coupling. I will present investigations on the spontaneous appearance of vector vortex beams in a VCSEL with frequency-selective feedback with a radial, spiral and hyperbolic polarization structure and their interpretation as high order vectorial solitons. The role of the feedback loop in controlling birefringence will be elucidated. Potential extensions to spin-orbit coupling of light, topological states and the inclusion of carrier spin are discussed as well as mode-locking these states.