Resonant light scattering by a subwavelength dielectric resonator array can show narrow, highly tunable resonant lineshapes from the interaction among multiple resonances. Several approaches have been introduced to control the spectral response of resonant light scattering, including optimization of the aspect ratio of cylindrical resonators, breaking in-plane inverse symmetry of coupled resonators, and operating periodic structures at the Γ point in reciprocal space. In this paper, we report the experimental demonstration of the control of resonant light scattering by subwavelength spiral resonator arrays. The fabricated metasurfaces support two types of resonances: the first one characterized by a Lorentzian peak with a long lifetime and the second type with a short lifetime supported by the lattice. By controlling the coupling strength between these two resonances through tailored broken symmetries, the resonant line shape of the spiral metasurface can be precisely tuned. The measured spectra show an ultrawide frequency tuning (over 16 THz) of the resonant mode by changing the spiral parameter at a fixed lattice constant. A temporal couple-mode theory combined with frequency-domain finite element method simulations was used to describe the measured transmission spectra of the fabricated metasurfaces.

中文翻译：

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螺旋超曲面中准束缚波的控制

亚波长介质谐振器阵列的谐振光散射可以显示出来自多个谐振之间相互作用的窄的、高度可调谐的谐振线形。已经引入了几种方法来控制共振光散射的光谱响应，包括优化圆柱形谐振器的纵横比，打破耦合谐振器的面内逆对称性，以及在倒易空间中的 Γ 点操作周期性结构。在本文中，我们报告了通过亚波长螺旋谐振器阵列控制谐振光散射的实验演示。制造的超表面支持两种类型的共振：第一种以长寿命的洛伦兹峰为特征，第二种以晶格支持的短寿命为特征。通过定制的破缺对称控制这两个共振之间的耦合强度，可以精确调整螺旋超表面的共振线形状。通过改变固定晶格常数的螺旋参数，测量的光谱显示了谐振模式的超宽频率调谐（超过 16 THz）。时间耦合模式理论与频域有限元方法模拟相结合，用于描述制造的超表面的测量透射光谱。