Superchirality induced ultrasensitive chiral detection in high-Q optical cavities
高Q值光学腔中超手性诱导的超灵敏手性检测
高Q光学共振器におけるスーパーチリアルリティ誘起の超感度チラル検出
슈퍼차일리티에 의해 유도된 초고감도 차일리티 검출 고-Q 광학 공동에서
Superquiralidad inducida en detección ultrasensible de quiralidad en cavidades ópticas de alta Q
Superchiralité induite pour une détection chiraux ultra-sensible dans des cavités optiques à haute Q
Суперхиральность, индуцирующая сверхчувствительное хиральное обнаружение в высококачественных оптических резонаторах
¹ Department of Optical Engineering, School of Electronic Science and Engineering, Southeast University, Nanjing 211189, China
中国 南京 东南大学电子科学与工程学院光学工程系
² Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
³ School of Mechanical Engineering, Southeast University, Nanjing 211189, China
中国 南京 东南大学机械工程学院
⁴ Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
⁵ Department of Electrical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
⁶ POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang 37673, Republic of Korea
The scale mismatch between nanoscale biomolecules and sub-wavelength light hinders circular dichroism (CD) spectroscopy for chiral small molecule sensing. In this study, we propose a high quality-factor (Q-factor) optical cavity that offers a breakthrough solution to the intrinsic trade-off between optical chirality density and mode loss.
A spin-preserving chiral metasurface utilizes bound states in the continuum (BIC)-guided mode resonance (GMR) degenerate modes to achieve a high Q-factor, while ensuring the preservation of chirality purity for circularly polarized light propagating within the cavity via spin-locking mechanism. Experimental results demonstrate that the BIC-GMR degenerate state enables near-perfect transmission CD up to 0.99, without requiring symmetry breaking.
Full-wave simulations further predict that this synergistically enhanced system can achieve a Q-factor as high as 10,037 and generate a localized field in the molecular interaction region with an optical chirality density enhancement of up to 400-fold, leading to 5025-fold amplification of the CD signal. This study establishes a foundation for detecting low-concentration chiral molecules, reveals high-Q enhancement, and advances chiral toward single-molecule sensitivity, opening new research avenues in chiral biosensing.
