论文标题
高Q引导模式的共振，带有近板散布的交叉光栅
High-Q guided-mode resonance of a crossed grating with near-flat dispersion
论文作者
论文摘要
衍射光栅中的引导模式共振表现为反射（传输）光谱中的峰（倾角）。较小的共振线宽度（较高的Q因子）可确保更强的光 - 物质相互作用，并且对现场依赖的物理过程有益。但是，强角和光谱分散是这种高Q共振所固有的。我们证明，表现出非常弱的分散体的一类高Q共振模式（Q-Factor> 1000）可以与具有众所周知的几乎线性分散体的模式同时进行交叉光栅。此外，我们表明，可以调整传入光的极化以设计这些模式的分散体，并通过在两个相互正交的线性极化状态之间切换来实现强到近灯的分散或反之亦然。我们介绍了一个半分析模型，以解释这些观察结果背后的基本物理，并进行全波数值模拟和实验以支持我们的理论猜想。此处介绍的结果将使依赖于自由空间耦合几何形状的共振的所有应用程序受益。
Guided-mode resonances in diffraction gratings are manifested as peaks (dips) in reflection (transmission) spectra. Smaller resonance line widths (higher Q-factors) ensure stronger light-matter interactions and are beneficial for field-dependent physical processes. However, strong angular and spectral dispersion are inherent to such high-Q resonances. We demonstrate that a class of high-Q resonant modes (Q-factor >1000) exhibiting extraordinarily weak dispersion can be excited in crossed gratings simultaneously with the modes with well-known nearly linear dispersion. Furthermore, we show that the polarization of the incoming light can be adjusted to engineer the dispersion of these modes, and strong to near-flat dispersion or vice-versa can be achieved by switching between two mutually orthogonal linear polarization states. We introduce a semi-analytical model to explain the underlying physics behind these observations and perform full-wave numerical simulations and experiments to support our theoretical conjecture. The results presented here will benefit all applications that rely on resonances in free-space-coupled geometries.
