4-bit millimeter-wave Janus metasurface enabled polarization-spatial multiplexing holography.

Metasurface holography has become a surging and revolutionized field due to its flexible manipulation of amplitude and/or phase, which enhances the quality and capacity of holographic images. However, the current meta-holograms primarily focus on half-space manipulation, posing a challenge in developing simplified meta-hologram structures for spatial multiplexing. To address this situation, what we believe to be a novel 4-bit "Janus" metasurface combined with the weighted Gerchberg-Saxton (WGS) algorithm is proposed to record and reconstruct two distinct images in millimeter wave band.

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.

Multifield-Controlled Terahertz Hybrid Metasurface for Switches and Logic Operations.

Terahertz (THz) meta-devices are considered to be a promising framework for constructing integrated photonic circuitry, which is significant for processing the upsurge of data brought about by next-generation telecommunications. However, present active metasurfaces are typically restricted by a single external driving field, a single modulated frequency, fixed switching speed, and deficiency in logical operation functions which prevents devices from further practical applications. Here, to overcome these limitations, we propose a hybrid THz metasurface consisting of vanadium dioxide (VO) and germanium (Ge) that enables electrical and optical tuning methods individually or simultaneously and theoretically investigate its performance.