Active metasurfaces based on phase transition material vanadium dioxide

Dynamic properties play a vital role in modern optical devices, including light detection and ranging systems, display devices, and digital cameras. Active metasurfaces provide an attractive scheme for the miniaturization and integration of dynamic optical systems compared with traditional bulk optical devices. Phase transition materials are great candidates for the design of active metasurfaces due to their high contrast refractive index and simple control characteristics. Here, we present a tunable metalens and switchable image coding metasurface in the near-infrared region through the control of the phase transition of vanadium oxide. By adjusting the phase transition of vanadium oxide, the focal intensity of the metalens is changed, and a switching effect with an intensity contrast of similar to 12 times is demonstrated. In addition, the switchable imaging of two different numbers has been achieved in two different phase states. This work provides potential opportunities to realize active metasurfaces for imaging and encryption systems.

Automated summary

Dynamic properties are essential in modern optical devices, and active metasurfaces provide a promising approach for miniaturizing and integrating dynamic optical systems. Phase transition materials, with their high refractive index and simple control characteristics, are ideal candidates for designing active metasurfaces. In this study, we demonstrate a tunable metalens and switchable image coding metasurface in the near-infrared region by controlling the phase transition of vanadium oxide. This work opens up possibilities for active metasurfaces in imaging and encryption systems.