Light‐Controllable Digital Coding Metasurfaces

TLDR

Digital coding metamaterials enable real‑time electromagnetic wave manipulation with a single configuration, but their active components require individually wired, computer‑controlled connections, a challenge that escalates with device complexity. The authors propose a remotely tunable metasurface that can be addressed and controlled by illuminating light. The metasurface uses light‑addressable elements whose response is tuned by varying LED illumination intensity, allowing dynamic beam reconfiguration without control circuitry. Microwave experiments confirm that the light‑controlled metasurface can dynamically reconfigure radiation beams, demonstrating a contact‑free remote tuning approach.

Abstract

Abstract Since the advent of digital coding metamaterials, a new paradigm is unfolded to sample, compute and program electromagnetic waves in real time with one physical configuration. However, one inconvenient truth is that actively tunable building blocks such as diodes, varactors, and biased lines must be individually controlled by a computer‐assisted field programmable gate array and physically connected by electrical wires to the power suppliers. This issue becomes more formidable when more elements are needed for more advanced and multitasked metadevices and metasystems. Here, a remote‐mode metasurface is proposed and realized that is addressed and tuned by illuminating light. By tuning the intensity of light‐emitting diode light, a digital coding metasurface composed of such light‐addressable elements enables dynamically reconfigurable radiation beams in a control‐circuitry‐free way. Experimental demonstration is validated at microwave frequencies. The proposed dynamical remote‐tuning metasurface paves a way for constructing unprecedented digital metasurfaces in a noncontact remote fashion.