Transmissive reconfigurable metasurface enabling independent control of active and passive modules through weak coupling

• Kun Xue, Cilei Zhang, Yonghao Zhang, Haoliang Sun, Heng Wei, and Shaohua Dong
• received 01/03/2024; accepted 05/09/2024; posted 05/09/2024; Doc. ID 517652
• Abstract: Metasurfaces have demonstrated rich electromagneticcontrol capabilities and degrees of freedom in past years.As is well-known, for passive metasurfaces, theirfunctionalities cannot be further expanded accordinglyonce prototypes are established. Therefore,reconfigurable metasurfaces, utilizing active devices toreplace geometric changes in passive structures, havereceived widespread attentions, especially with thedevelopment of wireless communication recently. Inreconfigurable metasurfaces, artificial meta-atoms arecomposed of active devices and passive structurescombined together. However, these two modules areusually utilized as a whole due to the tight coupling of theactive devices and the passive structures, which results inpassive structures not receiving sufficient attention andbeing utilized as independent degrees of freedom. In thisletter, we propose the concept of weakly-coupledreconfigurable metasurfaces in transmissive systems,enabling independent control of active and passivemodules through weak coupling. As the proof of theconcept, a simple weakly-coupled system is proposed,which can realize the transmission wavefront engineeringthrough the geometric changes of meta-structures inpassive mode, while achieving switching betweentransmission and reflection states in active mode,respectively. Our exploration lies in taking the use of thephysical structure which is easily neglected in traditionalreconfigurable metasurface design, emphasize thecollaborative work of active and passive modules, exploremore available variables within the same aperture, andprovide a potential solution for balancing functionalityand resource consumption in practical applications.