Abstract
Achiral metasurfaces with near-field optical chirality have attracted great attention in molecular sensing and chiral emission control. Here, the circular dichroism (CD) response of an achiral metasurface induced by spatially selective coupling with polymethyl methacrylate (PMMA) molecules is demonstrated. A designed achiral metasurface with a V-shaped resonator exhibits large optical chirality with a strongly dissymmetric distribution under circular polarization. By introducing a PMMA molecule layer on top of the metasurface, which covers the area with large optical chirality, CD in absorption of 0.38 and a dissymmetric factor of optical chirality gc of 0.16 are obtained. Furthermore, an analysis of the coupled harmonic oscillator model reveals stronger coupling strength between the PMMA layer and the metasurface under RCP incidence, compared to the LCP case. Moreover, it is shown that the far-field CD response of the metasurface is linearly correlated with the dissymmetric near-field optical chirality distribution. The demonstrated results present the potential for advancing applications in chiral molecule vibrational sensing, thermal emission control, and infrared chiral imaging.
Recommended Citation
B. Han et al., "Circular Dichroism in Achiral Metasurfaces Induced by Spatially Selective Coupling with Molecules," Optics Letters, vol. 50, no. 2, pp. 399 - 402, Optica Publishing Group, Jan 2025.
The definitive version is available at https://doi.org/10.1364/OL.537725
Department(s)
Mechanical and Aerospace Engineering
International Standard Serial Number (ISSN)
1539-4794; 0146-9592
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2025 Optica Publishing Group, All rights reserved.
Publication Date
15 Jan 2025
PubMed ID
39815521
Comments
National Science Foundation, Grant ECCS-2230069