Graphene-based metasurfaces for switching polarization states of anomalous reflection and focusing

Metasurfaces have shown great potential to manipulate electromagnetic waves, and hence have found numerous applications in photonics. However, the functionalities of most of the reported metasurfaces are polarization unfriendly after the fabrication process and cannot be reconfigured dynamically with switchable polarization. Here, graphene-based metasurfaces are proposed to exhibit polarization-switchable electromagnetic response before and after switch of the chemical potential of graphene. The phase shifts covering a considerable phase range (with respect to 2π) can be switched from x polarization to y polarization by tuning the chemical potential of graphene from one value to another one. High-performance polarization-switchable anomalous reflection and focusing have been demonstrated with the designed metasurfaces. The presented design strategy can be applied to make other polarization-switchable metadevices in different frequency domains, and impact numerous photonic applications.