Hu Haiyang, Lu Wenzheng, Antonov Alexander, Berté Rodrigo, Maier Stefan A, Tittl Andreas
Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, Königinstraße 10, München, Germany.
School of Physics and Astronomy, Monash University Clayton Campus, Melbourne, Victoria, Australia.
Nat Commun. 2024 Aug 15;15(1):7050. doi: 10.1038/s41467-024-51340-7.
Achieving precise spectral and temporal light manipulation at the nanoscale remains a critical challenge in nanophotonics. While photonic bound states in the continuum (BICs) have emerged as a powerful means of controlling light, their reliance on geometrical symmetry breaking for obtaining tailored resonances makes them highly susceptible to fabrication imperfections, and their generally fixed asymmetry factor fundamentally limits applications in reconfigurable metasurfaces. Here, we introduce the concept of environmental symmetry breaking by embedding identical resonators into a surrounding medium with carefully placed regions of contrasting refractive indexes, activating permittivity-driven quasi-BIC resonances (ε-qBICs) without altering the underlying resonator geometry and unlocking an additional degree of freedom for light manipulation through active tuning of the surrounding dielectric environment. We demonstrate this concept by integrating polyaniline (PANI), an electro-optically active polymer, to achieve electrically reconfigurable ε-qBICs. This integration not only demonstrates rapid switching speeds and exceptional durability but also boosts the system's optical response to environmental perturbations. Our strategy significantly expands the capabilities of resonant light manipulation through permittivity modulation, opening avenues for on-chip optical devices, advanced sensing, and beyond.
在纳米尺度上实现精确的光谱和时间光操纵仍然是纳米光子学中的一项关键挑战。虽然连续统中的光子束缚态（BICs）已成为控制光的一种强大手段，但它们依赖于几何对称性破缺来获得定制共振，这使得它们极易受到制造缺陷的影响，而且其通常固定的不对称因子从根本上限制了在可重构超表面中的应用。在此，我们引入环境对称性破缺的概念，即将相同的谐振器嵌入到具有精心放置的折射率对比区域的周围介质中，激活由介电常数驱动的准BIC共振（ε-qBICs），而不改变底层谐振器的几何形状，并通过对周围介电环境的主动调谐解锁用于光操纵的额外自由度。我们通过集成聚苯胺（PANI）（一种电光活性聚合物）来实现电可重构的ε-qBICs，从而证明了这一概念。这种集成不仅展示了快速的开关速度和出色的耐久性，还增强了系统对环境扰动的光学响应。我们的策略通过介电常数调制显著扩展了共振光操纵的能力，为片上光学器件、先进传感等开辟了道路。
