Research / 2019 / Article / Fig 1

Review Article

Tunable/Reconfigurable Metasurfaces: Physics and Applications

Figure 1

Electrically tunable metasurfaces. (a) Switching performance of semiconductor-hybridized ETMs in THz regime. Inset: schematics of the designed metadevices. (b) Plasmon-resonance tuning on graphene microribbon array achieved by varying the electrical gating voltage applied across the graphene ribbons. Insets: metadevice configuration and image of the fabricated graphene ribbons. (c) Wide-range phase modulations on THz waves achieved with electrically gated MIM graphene metasurfaces. Inset: schematics of the MIM graphene metasurface. (d) Dynamic reflection-phase control on IR light achieved with an MIM ETM incorporated with ENZ materials (ITO). Inset: phase of reflected IR light at 5.94 um under different bias voltages. (e) An ITO-involved dual-gated ETM for wide-range reflection-phase modulation (>300°) at 1550 nm. Inset: schematics of the meta-atom design. (f) THz tunable meta-absorber based on MIM meta-atoms incorporated with liquid crystals. Inset: structure of the building meta-atom and the operational principle. Reproduced with permissions: (a) from [24] ©2006 NPG; (b) from [25] ©2011 NPG; (c) from [26]; (d) from [27] ©2017 ACS; (e) from [28] ©2018 ACS; (f) from [29] ©2013 APS.