Abstract Actively tunable and reconfigurable wavefront shaping by optical metasurfaces poses a significant technical challenge often requiring unconventional materials engineering and nanofabrication. Most wavefront-shaping metasurfaces can be considered “local” in that their operation depends on the responses of individual meta-units. In contrast, “nonlocal” metasurfaces function based on the modes supported by many adjacent meta-units, resulting in sharp spectral features but typically no spatial control of the outgoing wavefront. Recently, nonlocal metasurfaces based on quasi-bound states in the continuum have been shown to produce designer wavefronts only across the narrow bandwidth of the supported Fano resonance. Here, we leverage the enhanced light-matter interactions associated with sharp Fano resonances to explore the active modulation of optical spectra and wavefronts by refractive-index tuning and mechanical stretching. We experimentally demonstrate proof-of-principle thermo-optically tuned nonlocal metasurfaces made of silicon and numerically demonstrate nonlocal metasurfaces that thermo-optically switch between distinct wavefront shapes. This meta-optics platform for thermally reconfigurable wavefront shaping requires neither unusual materials and fabrication nor active control of individual meta-units.

中文翻译：

---

活性非局部超表面

摘要 通过光学超表面进行主动可调和可重构波前成形带来了重大的技术挑战，通常需要非常规材料工程和纳米制造。大多数波前成形超表面可以被认为是“局部的”，因为它们的操作取决于单个元单元的响应。相比之下，“非局部”超表面基于许多相邻元单元支持的模式发挥作用，从而产生清晰的光谱特征，但通常没有对出射波前的空间控制。最近，基于连续体中准束缚态的非局部超表面已被证明仅在支持的 Fano 共振的窄带宽上产生设计波前。这里，我们利用与尖锐 Fano 共振相关的增强的光物质相互作用来探索通过折射率调谐和机械拉伸对光谱和波前的主动调制。我们通过实验证明了由硅制成的原理热光调谐非局部超表面，并在数值上证明了在不同波前形状之间进行热光切换的非局部超表面。这种用于热可重构波前成形的元光学平台既不需要不寻常的材料和制造，也不需要对单个元单元的主动控制。我们通过实验证明了由硅制成的原理热光调谐非局部超表面，并在数值上证明了在不同波前形状之间进行热光切换的非局部超表面。这种用于热可重构波前成形的元光学平台既不需要不寻常的材料和制造，也不需要对单个元单元的主动控制。我们通过实验证明了由硅制成的原理热光调谐非局部超表面，并在数值上证明了在不同波前形状之间进行热光切换的非局部超表面。这种用于热可重构波前成形的元光学平台既不需要不寻常的材料和制造，也不需要对单个元单元的主动控制。