Switchable multichannel vortex beam generation via temperature response and polarization multiplexing
Min Liu, Zhi Xu, Zhengyong Song
Abstract
Abstract Vortex beams (VBs) hold substantial importance within the realms of optics and photonics. Currently, while numerous studies have focused on generating VBs using metasurfaces, most schemes are restricted to static modulation. Vanadium dioxide (VO 2 ) exhibits significant insulator–metal transition properties, and its physical properties change under specific temperature or external stimuli. VO 2 is an ideal candidate for designing dynamic metasurfaces and is expected to break through the static limitations of existing VB generation techniques. In this study, we propose an innovative scheme to generate polymorphic VBs using VO 2 metasurface. In this scheme, meta-atoms are especially designed to exhibit different optical responses at different temperatures. When VO 2 is metallic, multiple VBs with different topological charges (TCs) in the far field are generated in three polarization channels. When VO 2 undergoes insulation, focused VBs with specific TCs in the near field are generated in three different channels. Therefore, multichannel VBs can be switched by temperature response and polarization multiplexing. Our scheme provides a novel way to dynamically generate and manage VBs.