From Tunable and Reconfigurable to Space-Time Modulated Multifunctional Metasurfaces

This abstract introduces a reconfigurable and multifunctional metasurface platform, that can adapt to various functional demands. It is shown that, by locally controlling parameters of each meta-atom, the metasurface can perform multiple reciprocal functions. In addition, by modulating the meta-atoms in both space and time, the same metasurface can provide nonreciprocal functionalities such as wave circulation and isolation. Switching between different electromagnetic functionalities is realized by setting different parameter values or different time modulation laws for tunable components embedded in each meta-atom, without the necessity of changing the metasurface body. We think that this technique is very promising for applications, especially in future adaptive and intelligent communication networks.