High-performance switchable perfect composite vortex beam generator based on halogen perovskite metasurfaces

Abstract

We propose and realize a novel high-performance switchable perfect composite vortex beam (PCVB). We introduce the concept of composite vortex beam and then present a design for a PCVB generator based on halogen perovskite metasurfaces, which can convert circularly polarized light into a parametrically tunable PCVB using a single halogen perovskite fully dielectric metasurface. The PCVB exhibits a constant toroidal intensity distribution and the ability to superimpose different topological charges. We demonstrate the high feasibility of this design to generate PCVBs with different operating wavelengths, topological charges, and numerical apertures. Additionally, we explore the practical application potential of our design by demonstrating reversible exchange between three halogen perovskite metasurfaces using chemical vapor deposition. This exchange leads to corresponding imaging effects at specific wavelengths. The proposed generator has significant application prospects in optical communication encryption, optical data storage, and optical tweezers.