Photon‐Induced Ultrafast Multitemporal Programming of Terahertz Metadevices

Dynamic terahertz (THz) metasurface can feature modulated and multiplexed electromagnetic functionalities, important for wave-based computation, six-generation communications, and other applications. The versatile dynamic switching typically relies on a series of complex or incompatible multifield activations, with excessive system complexity, additional loss, slow modulation speed, and inertial time-varying properties, limiting more widespread applications. Here, a photon-induced ultrafast programmable THz metadevice is reoprted in time-frequency dimensions with polarization-decoupled temporal responses. By the pixelated design with multi-materials and triggering switches, the multimodal modulation transcends the constraints inherent in materials, enabling the ultrafast programmable temporal evolution. All the resonances can be independently programmed at the working band from 0.6 to 2 THz. The tri-temporal (with switching time of 1.25, 1, and 4.75 ps) and bi-temporal (with switching time of 2.25 and 4.75 ps) dynamic manipulations are performed by all-optical driven molecularization process of hybrid metasurfaces loaded with silicon (Si) and germanium (Ge) under different polarizations. Combining these features, the temporally programmed THz logic gates are last experimentally demonstrated, possessing basic operation of XNOR, NOR, and OR, as a proof-of-concept application. This reported light-driven programmable THz flat-optics allows ultrafast hybrid molecularization processes and new possibilities for miniaturized, flexible, multifunctional, and temporally programmable integrated devices.