Abstract
Broadband tuning of polarization states is pivotal yet challenging in modern photonics technologies, especially for miniaturized or integrated systems. Metasurfaces potentially provide an effective approach to resolve this challenge. However, once a metadevice is fabricated, its functionalities are determined, and it is hard to actively tune the polarization states. Here, the electrically tunable broadband polarization states by combining phase-change material (vanadium dioxide) and dispersion-free metasurface are demonstrated for the first time. The polarization states are modulated through the electrically driven, Joule-heat-induced phase transition of vanadium dioxide, where the output polarization state can be continuously tuned from horizontal one to vertical one, or from circular polarization to linear polarization. With accurate on-chip control of the phase transition, continuous and reversible modulation of polarization is verified in a scanning display. Moreover, a proof-of-concept demonstration for dynamically independent control of multiple polarization display is carried out. Different images are produced by applying electrical currents in N separate channels to generate a dynamic multiplexing polarization display with 2(N) encoding states. Such an active metasurface can be readily integrated with electronics and has potential applications in display, encryption, camouflage, and information processing.