Holographic imaging film based on surface plasma coupling structure

The invention discloses a holographic imaging film based on a surface plasma coupling structure. Electron beam lithography is used to prepare an asymmetric nanostructure layer. According to the nano processing technology, Bosch technology is used for reactive ion etching, SF6 is used for etching, C4F6 is used to generate a polymer, etching and passivation are carried out alternatively, the scallop-shaped sidewall shape is formed via horizontal undercutting, a dielectric nano column is obtained, a metal film is deposed in the direction vertical to a substrate, and a metal nanostructure-metal film coupling structure is obtained. A meta-material of the sub-wavelength coupling structure presents harmonic resonance and dark-field excitation plasma resonance modes in a visible light spectrum, multi-formant narrowband resonance is generated, the asymmetric upper-layer nanostructure enables that a reflection array is flexible in color response and high in reflectivity to different incident fields, the reflection arra