Intrinsic Chiralityof Dielectric Metasurfaces Unlockedby Resonant Chiral Modes
NANO LETTERS, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1021/acs.nanolett.6c02271
- Dergi Adı: NANO LETTERS
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, EMBASE, INSPEC, MEDLINE
- İstanbul Üniversitesi Adresli: Evet
Özet
Controlling optical chirality at the subwavelength scale is essential for applications of nanophotonic structures in polarization optics, sensing, and nonlinear photonics. Achieving a strong chiroptical response in planar dielectric metasurfaces without intrinsically chiral meta-atoms remains challenging. A recent study proposed a novel mechanism of metasurface chirality and predicted that bilayer metasurfaces with rotated C-4-symmetric apertures can exhibit a chiral response originating from resonant chiral photonic modes. Here, we experimentally confirm this concept by demonstrating resonantly enhanced circular dichroism in the near-infrared. We fabricated a free-standing silicon membrane metasurface that is nominally achiral. Breaking the out-of-plane symmetry with a thin PMMA layer unlocks and activates a strong chiral response. The observed circular dichroism is governed by chiral photonic modes, interlayer coupling, and symmetry breaking, in agreement with theoretical predictions. These results establish bilayer metasurfaces as a simple and versatile platform for engineering strong mode-induced chirality in compact planar photonic metadevices.