Observation of chiral bound states in the continuum in self-biased magneto-optical photonic crystals

• 成果类型: Article
• 署名作者: Gong, Maohua; Zhen, Qiutong; Tang, Yujie; Hu, Peng; Tu, Qing-An; Meng, Yan; Zhou, Peiheng; Gao, Zhen
• 署名单位: Southern University of Science & Technology; University of Electronic Science & Technology of China; Chongqing University of Technology; Beijing Institute of Technology
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.2536341123
• 发表日期: 2026-05-26
• 页码: e2536341123
• 关键词: chiral bound states in the continuum; self-biased magneto-optical photonic crystals; magneto-optical coupling; light

摘要

Chiral bound states in the continuum (BICs) are confined photonic modes with infinite quality factors and chiral response, offering significant potential for chiral optics. Although a novel type of spin-orbital-locking chiral BIC was recently predicted in magneto-optical (MO) photonic crystals (PhCs) that break time-reversal symmetry (TRS), its experimental realization has remained elusive. Here, we report an experimental observation of such chiral BICs in self-biased MO PhCs, which operate without external magnetic fields. Moreover, we experimentally demonstrate that the chirality and the surrounding near-circular polarization of these chiral BICs can be switched simply by reversing the remanent magnetization, without any structural changes. Unlike conventional chiral BICs that preserve TRS, these magnetically induced chiral BICs exhibit exceptional robustness against structural imperfections and perturbations. This work represents a significant advancement in topological photonics for chiral BICs, opening pathways toward robust chiral optical devices.