High-efficiency metadevices for bifunctional generations of vectorial optical fields

Abstract

Vectorial optical fields (VOFs) exhibiting tailored wave fronts and spatially inhomogeneous polarization distributions are particularly useful in photonic applications. However, devices to generate them, made by natural materials or recently proposed metasurfaces, are either bulky in size or less efficient, or exhibit restricted performances. Here, we propose a general approach to design metadevices that can efficiently generate two distinct VOFs under illuminations of circularly polarized lights with different helicity. After illustrating our scheme via both Jones matrix analyses and analytical model calculations, we experimentally demonstrate two metadevices in the near-infrared regime, which can generate vortex beams carrying different orbital angular momenta yet with distinct inhomogeneous polarization distributions. Our results provide an ultracompact platform for bifunctional generations of VOFs, which may stimulate future works on VOF-related applications in integration photonics.

Keywords

• bifunctional metasurfaces
• local polarization distributions
• pancharatnam–berry phase
• resonance phase
• spin-decoupled functionalities
• vectorial optical fields