Bio-inspired Photonic Masquerade with Perturbative Metasurfaces.

Camouflage is critical for many living organisms to survive in the natural world and has stimulated applications, such as optical cloaking and military affairs. However, most applications adopt crypsis-type camouflage that prevents the organisms from being detected by matching the environment, which is challenging to realize the large angle-of-view and broadband operation at optical frequencies. Here, as inspired by nature's system of masquerade, we demonstrate an optical masquerade, being detected but not recognized, with perturbative metasurfaces that could camouflage an object into another unrelated one under the oblique (±69°) illumination of visible light with an ∼160 nm bandwidth. Predicted by the perturbation theory, the dielectric metastructures encircling a pistol-shaped object have a thin layer of nanodisk array, which can suppress the electromagnetic resonances of nanomodes for mimicking the transmitted intensity and phase of the camouflaged object. We also exhibit that optical masquerade is an invasive, environment-independent, object-unlimited, and material-extendable camouflage, which might benefit optical security, anticounterfeiting, and encoding.