TY - JOUR
T1 - High-order photonic degeneracy enables topological reconfiguration in bound states in the continuum
AU - Fu, Zhenchu
AU - Chen, Yang
AU - Shi, Fulong
AU - Jin, Rong
AU - Guo, Jiaoyang
AU - Zhang, Yukang
AU - Yu, Feilong
AU - Chen, Jin
AU - Huang, Lujun
AU - Zhou, Chaobiao
AU - Chen, Xiaoshuang
AU - Lu, Wei
AU - Alù, Andrea
AU - Li, Guanhai
AU - Qiu, Cheng Wei
N1 - Publisher Copyright:
© The Author(s) 2026.
PY - 2026/12
Y1 - 2026/12
N2 - Extreme suppression of free-space radiation in open planar photonic systems remains a long-standing goal in nanophotonics. Conventional bound states in the continuum (BICs), constrained by symmetry-protected or accidental singularities, restrict experimental Q-k scaling exponents to n = 2-8 because ordinary bands lack sufficient degrees of freedom to host, redistribute or merge additional radiation-suppressing singularities. Here we demonstrate a degeneracy-driven topological-reconfiguration mechanism: an E2-type high-order degeneracy at Γ acts as a multi-charge reservoir, enabling controlled release, inversion and merging of topological charges under symmetry breaking. This unlocks a Q ∝ k−10 radiation-suppression regime in a single-layer all-dielectric metasurface. Experimentally, we realize ultrahigh free-space Q-factors with 3% geometric robustness and a maximum Q of 1.1 × 106. A 100-pixel array exploiting these resonances demonstrates picometre-scale spectral discrimination by resolving ultranarrow H13C14N absorption lines. These results establish high-order-degeneracy-enabled BIC physics for robust ultrahigh-Q photonics and precision free-space spectroscopy.
AB - Extreme suppression of free-space radiation in open planar photonic systems remains a long-standing goal in nanophotonics. Conventional bound states in the continuum (BICs), constrained by symmetry-protected or accidental singularities, restrict experimental Q-k scaling exponents to n = 2-8 because ordinary bands lack sufficient degrees of freedom to host, redistribute or merge additional radiation-suppressing singularities. Here we demonstrate a degeneracy-driven topological-reconfiguration mechanism: an E2-type high-order degeneracy at Γ acts as a multi-charge reservoir, enabling controlled release, inversion and merging of topological charges under symmetry breaking. This unlocks a Q ∝ k−10 radiation-suppression regime in a single-layer all-dielectric metasurface. Experimentally, we realize ultrahigh free-space Q-factors with 3% geometric robustness and a maximum Q of 1.1 × 106. A 100-pixel array exploiting these resonances demonstrates picometre-scale spectral discrimination by resolving ultranarrow H13C14N absorption lines. These results establish high-order-degeneracy-enabled BIC physics for robust ultrahigh-Q photonics and precision free-space spectroscopy.
UR - https://www.scopus.com/pages/publications/105048770674
U2 - 10.1038/s41467-026-75967-w
DO - 10.1038/s41467-026-75967-w
M3 - 文章
C2 - 42660896
AN - SCOPUS:105048770674
SN - 2041-1723
VL - 17
JO - Nature Communications
JF - Nature Communications
IS - 1
M1 - 9203
ER -