Electrically controlled real-time terahertz “microladder” integrated with VO2 patches for broadband holographic encryption

High-quality and real-time holographic imaging based on dynamically tunable metasurfaces has attracted immense interest. Despite remarkable progress, the complex electrical pattern designs and slow-speed near-field scanning terahertz (THz) microscopy systems have significantly hindered the development of real-time electrically tunable metasurface holography in the THz band. We propose and experimentally demonstrate an electrically tunable vanadium dioxide (VO₂)-based active metasurface that can generate real-time bias-controlled holographic information via a THz focal plane imaging system. By elaborately designing “microladders” integrated with VO₂ pads, the device exhibits low power consumption (∼0.8 W) and real-time imaging (∼4.5 s). The quantitative method is theoretically utilized to investigate the thermal parameters dependent thermodynamics of the “ladder” metasurface based on theoretical analysis with the aid of thermal modelling. The calculated dynamic response time based on the quantitative thermodynamic model agrees well with experimental results. Our study can be used to propel the development of THz electrically tunable metasurfaces for low-power-consumption dynamic, real-time displays, and information encryption, providing crucial insights for future optimization of VO₂-based electrothermally tunable holographic metasurfaces. © The Authors.