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