Babinet’s meta-apertures for holographic bi-imaging

Complementary metasurfaces based on Babinet’s principle have shown remarkable performance in optical applications like polarization conversion and split ring resonators by dynamically reversing the properties of light in both transmission and reflection modes. However, complementary diffractive metasurfaces for different holographic images have not yet proven to be effective because Babinet’s principle predicts identical diffraction patterns from complementary surfaces. Here, we report carefully designed complementary metasurfaces consisting of an engineered metallic aluminum layer sitting on a transparent quartz substrate. Upon illumination, both complementary devices output entirely different diffractive intensity profiles from each other, yielding two holographic images at visible wavelengths from 430 nm to 650 nm. It provides experimental evidence for encoding two images into complementary metasurfaces, indicating an exception of Babinet’s principle in the Fresnel region of complementary apertures.