Programmable metasurfaces with high angular stability for arbitrarily-polarized obliquely-incident waves

Abstract

Abstract Programmable metasurfaces show enormous potential in real-time electromagnetic (EM) manipulation and their stable responses for variable EM waves including incident angle and polarization changes is crucial for related applications. However, the demonstrated programmable metasurfaces are commonly considered in normal-incident wave with fixed polarization; how to achieve stable performance in more realistic scenarios of wide-angle and full-polarized wave incidences is still a challenge. Here, we propose and realize a wide-angle and full-polarization programmable metasurface, which can generate stabilized amplitude and phase responses at both transverse electric (TE) and transverse magnetic (TM) oblique incidences. These are achieved by introducing the metallic walls around the metasurface element to reduce element coupling, which greatly improves the angular stability of its reflection responses. The mechanisms of angular insensitivity are analyzed comprehensively, and as a proof of concept, the obliquely-incident beam steering, large-angle beam scanning and oblique vortex beam emitting are demonstrated on this programmable metasurface. Both the simulation and experimental results demonstrate that the programmable metasurface can operate well at both TE and TM wide-angle oblique incidences in the upper half space. Our work offers an actual route for improving the angular stability and polarization insensitivity of metasurface, which could push it one step closer towards more complicated applications.