A light-programmable metamaterial based on pixelated phase transition of vanadium dioxide (VO₂)

The development of dynamically programmable metamaterials capable of manipulating electromagnetic (EM) waves is essential for next-generation adaptive stealth, communication, and imaging systems. However, achieving both high modulation depth and spatial reconfigurability remains a major challenge due to the inherent limitations of conventional electronic tuning elements. Herein, we demonstrate a novel digitally programmable and fully reconfigurable metamaterial absorber based on pixelated optical control of the semiconductor-to-metal phase transition in vanadium dioxide (VO₂). The prototype integrates a VO₂ thin-film array with a high-power blue-LED pixelated light source (PLS) system and a fused-silica light-guiding column module array (LGCMA), enabling on-demand "writing" and "erasing" of conductive patterns on the VO₂ surface without metallic wiring. This design achieves strong, dynamically tunable absorption from 2 to 18 GHz, with peak reflection reduction exceeding 37.5 dB and spatial reconfigurability at the 5-mm pixel level. The non-contact optical control strategy eliminates EM interference (EMI), while the abrupt conductivity change in the non-etched VO₂ patterns ensures exceptional modulation depth and design flexibility. This work transcends conventional frequency-shift tuning by introducing spatially programmable absorption, opening a pathway towards software-defined microwave devices for adaptive EM manipulation.