Fig. 1

Schematic of the proposed device. Thickness are: bottom Al mirror, 40 nm; Al₂O₃, 15 nm, ITO layer, 15 nm. Top metasurface is composed of square patch nanoantennas that are 20 nm thick with side length of 450 nm, and are set at a pitch of 600 nm. Electrodes are connected between bottom Al and ITO layer to generate an electric field inside the insulator. The incident direction of the light is perpendicular to the surface