An asymmetric trimeric slit metasurface structure is proposed herein, which generated independently tunable double Fano resonances (DFRs), namely, Fano1 and Fano2. Rigorous simulations and experimental scanning near-field demonstrated that the non-radiative dark mode produces Fano1, while the magnetic toroidal mode generates peak Fano2. The mechanisms of the two Fano resonances infer that interference fields can be independently tuned by different geometric parameters. The separate tuning of DFRs is simultaneously generated in the asymmetric slit metasurface. These results imply the potential applications of Fano resonances, such as lasing and sensing.

中文翻译：

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分别调整容易的不对称狭缝超表面中的双Fano共振

本文提出了一种不对称的三聚体狭缝超表面结构，其产生独立可调的双Fano共振（DFR），即Fano1和Fano2。严格的模拟和实验扫描近场表明，非辐射暗模式会产生Fano1，而磁环模式会产生峰值Fano2。两个Fano共振的机理表明，可以通过不同的几何参数独立地调整干扰场。DFR的单独调整同时在不对称狭缝超表面中生成。这些结果暗示了Fano共振的潜在应用，例如激光和传感。