Single-layer dielectric metasurface with an intrinsic chiral optical response in the yellow light region

Chirally responsive metasurfaces have a wide range of applications in nanophotonics, including imaging, virtual reality, and optical encryption. Most metasurfaces, with a high chiral optical response, are typically constructed from two or more layers of metasurfaces stacked with a rotational or translational offset. This requires precise layer alignment, increasing fabrication difficulty and cost. This work introduces a single-layer dielectric metasurface with an intrinsic chiral optical response in the yellow light region, with a maximum circular dichroism transmission value of 0.415. The proposed metasurface leverages a structure with <i>C</i>₄ rotational symmetry to induce constructive or destructive interference and to provide a high degree of freedom. Additionally, multipole decomposition is also employed to analyze the Mie resonances that dominate the light scattering behavior. These results help expand the applications of chiral dielectric metasurface in the fields of optical encryption, display, enantiomer separation, and detection.