Giant Circular Dichroism in All-dielectric Planar Chiral Meta-GMR

In this paper, we introduce a simplified approach involving a single-layer dielectric meta-surface on top of planar waveguide that can achieve a high circular dichroism (CD) value of 0.95 under normal incidence. Within this intrinsic chiral structure, we harness the distinctive characteristics of guided mode resonance (GMR) [1] to induce out-of-plane electric/magnetic field vectors during lateral light propagation, thereby enhancing its optical chirality. Notably, the enhanced CD value becomes prominent at a half-wave plate thickness. This meta-GMR design enables giant CD in both of reflection and transmission, offering promising applications in biosensing, especially for chiral molecules.