Dual-Mode Chiral Meta-Holography through All-Dielectric Nano-Surfaces in Visible Regime

Chiro-optical effects have numerous applications in optical displays, chiral sensing, and chiral imaging. The simultaneous control of amplitude, phase, and polarization with chirality in metasurfaces provides a compact and cost-effective solution for these applications. Here, we propose a planar all-dielectric metasurface based on anisotropic nano-bars instead of conventional chiral structures to avoid the fabrication complexities and the narrow bandwidth at the nanoscale. The fundamental meta-atom of the proposed metasurface contains a pair of nano-bars introducing giant chiro-optical effects in dual transmission mode at wide bandwidth of visible regime. The proposed meta-nano-surface provides the maximum asymmetric transmission of 77%. For the proof of concept, the phase mask of an image is encoded into the meta-nano-surface to reproduce chiral meta-hologram for circularly polarized light at RGB wavelengths. The demonstrated design provides a route to realize giant chiro-optical effects for promising application in optical displays, circular dichroism spectroscopy, circular polarizers, security, and imaging.