Spontaneously appearing vector vortex beams in vertical-cavity surface-emitting lasers with feedback

Abstract

Beams with a spatially non-uniform distribution of polarization attracted considerable recent interest due to their intrinsic beauty, novel functionalities in quantum optics and newly enabled applications [1]. Typical realizations investigated possess a circular symmetric intensity structure, most often in form of a doughnut, combined with a spatially non-uniform polarization field containing polarization singularities and are referred to as ‘vector vortex beams’. Typically, considerable engineering effort is necessary to create these non-trivial polarization configurations. In contrast, we report on the spontaneous formation of vector vortex beams in a broad-area vertical-cavity surface-emitting laser (VCSEL) with frequency-selective feedback [2]. In particular, an anti-vortex state with a hyperbolic polarization structure is observed. The relation to vectorial high-order solitons is discussed.