Multidimensional manipulation and encoding of versatile vector vortex beams empowered by phase-change metasurfaces

Abstract

Vector vortex beams, encompassing orbital angular momentum (OAM) and polarization states, have sparked considerable interest owing to their diverse potential applications. Although existing 3D optical devices are constrained to manipulating vector fields with a single function in one dimension, recent progressions have spawned compact and integrated approaches for multidimensional and multifunctional vector manipulation by leveraging metasurfaces, displacing cumbersome optical setups. Nonetheless, a notable obstacle lingers in achieving simultaneous control over the OAM and polarization states for focused vector beams using a single metasurface. Here, we introduce a versatile all-dielectric metasurface platform designed to generate vector vortex beams with customized OAM and polarization states. Employing a hybrid-phase modulation approach, we have successfully demonstrated three spin-multiplexed metasurface platforms capable of generating versatile vector vortex beams, featuring customized independent polarization states along the propagation path characterized by coplanar distinct topological charges coupled with longitudinal varying polarization states. This enables the creation of vector vortex beam arrays with coplanar-customized OAM accompanied by longitudinal varying polarization states, respectively. This platform operates by harnessing the coherent superposition of orthogonal circularly polarized components with unique topological charges while controlling their axial phase difference. Moreover, as a proof-of-concept demonstration, the third metasurface encoding customized OAM and polarization states in the parallel channels of versatile vector vortex beams are implemented for optical information encryption. Our findings not only enable the generation of complex vector fields with tailored OAM and polarization states but also open up new possibilities for advanced beam shaping, polarization switchable devices, information encryption, and versatile light-matter interactions.