Deciphering light transformation in chiral metasurface in real space and time by ultrafast electron microscopy.

ABSTRACT: Optical activity in chiral structures, i.e., circular dichroism (CD), has led to significant advances in nanoscale optical manipulation, including chiral metasurfaces, helicoid crystals, and chiral macromolecules. Although the local geometric design of chiral structures fundamentally governs their optical responses, the microscopic origin of CD remains unresolved due to the inability to probe optical chirality generation and local geometry effects with sufficient spatiotemporal resolution. Here, we unveil the light transformation process in a Γ-shaped chiral metasurface by combining far-field ellipticity measurements with direct near-field imaging at nanometer-femtosecond scale using photon-induced near-field electron microscopy (PINEM). By decomposing the near-field distributions into loc

SUBMITTER: Tong L 

PROVIDER: S-EPMC12800185 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature