초록 |
We propose the first dual-mode metasurface that operates under both coherent and incoherent light simultaneously. Conventional metasurfaces based on Pancharatnam-Berry phase only control the orientation of each nanoantenna to manipulate phase distribution, but the reflection spectrum is also controllable by changing the sizes of nanoantennas. Under incoherent white light the crypto-display works as a typical reflective display, whereas under coherent light, the encrypted information is revealed in the form of a hologram. Furthermore, the encrypted information does not affect the reflected image, so the information encoded in the crypto-display is not revealed unless coherent light is shone on it. |