Scholarlink

<p>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 <i>Q</i>-<b>k</b> scaling exponents to <i>n</i> = 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 E<sub>2</sub>-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 <i>Q</i> ∝ <b>k</b><sup>−10</sup> 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 <i>Q</i> of 1.1 × 10<sup>6</sup>. A 100-pixel array exploiting these resonances demonstrates picometre-scale spectral discrimination by resolving ultranarrow H<sup>13</sup>C<sup>14</sup>N absorption lines. These results establish high-order-degeneracy-enabled BIC physics for robust ultrahigh-Q photonics and precision free-space spectroscopy.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

High-order photonic degeneracy enables topological reconfiguration in bound states in the continuum

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年7月22日

查看全文
  • Zhenchu Fu,
  • Yang Chen,
  • Fulong Shi,
  • Rong Jin,
  • Jiaoyang Guo,
  • Yukang Zhang,
  • Feilong Yu,
  • Jin Chen,
  • Lujun Huang,
  • Chaobiao Zhou,
  • Xiaoshuang Chen,
  • Wei Lu,
  • Andrea Alù,
  • Guanhai Li,
  • Cheng-Wei Qiu

摘要

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.