Optica Open
Browse

Inverse Design of Chiral Structures for Giant Helical Dichroism

Download (5.58 kB)
preprint
posted on 2025-01-25, 17:00 authored by Chia-Chun Pan, Munseong Bae, Hongtao Wang, Jaesung Lim, Ranjith R Unnithan, Joel Yang, Haejun Chung, Sejeong Kim
Investigating chiral light-matter interactions is essential for advancing applications in sensing, imaging, and pharmaceutical development. However, the chiroptical response in natural chiral molecules and subwavelength chiral structures is inherently weak, with the characterization tool limited to optical methods that utilize the light with spin angular momentum (SAM). To overcome this, orbital angular momentum (OAM) beams, characterized by helical wavefronts, have emerged as a compelling research focus. Helical dichroism (HD) describes the differential absorbance of OAM beams with opposite signs of topological charges. By using inverse design with adjoint methods for topology optimization, we design the chiral structure optimized to increase HD response under OAM beam incidence, demonstrating a giant HD response of ~107% with topological charges $|\pm\ell|$ = 3 at the wavelength of 800 nm. This study reveals distinct helicity-dependent interactions between the structure and OAM beams, highlighting the potential for custom-tuned chiroptical responses.

History

Disclaimer

This arXiv metadata record was not reviewed or approved by, nor does it necessarily express or reflect the policies or opinions of, arXiv.

Usage metrics

    Categories

    Licence

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC