Reconfigurable reflective multifunction OAM metasurface based on spin-decoupling.

ABSTRACT

This Letter develops a spin-decoupled reconfigurable reflective orbital angular momentum (OAM) metasurface (MTS). The reconfigurability is realized by switching the feed among left-hand circular polarization (LHCP), right-hand circular polarization (RHCP), and linear polarization (LP) incidences, and the reconfigurable design principle is provided. This Letter also proposes a design method for the desired energy ratio between the co-polarized and cross-polarized beams. Compared with published multifunction MTSs, the designed MTSs have the following advantages multi-polarizations, arbitrary beam numbers and modes, composite waveform (pencil and OAM beams), high aperture efficiency (21.1%, 14.6%, 6.63% for RHCP, LP, and LHCP incidences, respectively), high purity (above 92.41%), required energy distribution ratio, and reconfigurability. The MTSs have potential prospects in high-capacity wireless communications.