Schwarz Ilai, Livneh Nitzan, Rapaport Ronen
Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel.
Opt Express. 2012 Jan 2;20(1):426-39. doi: 10.1364/OE.20.000426.
We present an intuitive reasoning and derivation leading to an approximated, simple closed-form model for predicting and explaining the general emergence of enhanced transmission resonances through rectangular, optically thick metallic gratings in various configurations and polarizations. This model is based on an effective index approximation and it unifies in a simple way the underlying mechanism of enhanced transmission as emerging from standing wave resonances of the different diffraction orders of periodic structures. The model correctly predicts the conditions for the enhanced transmission resonances in various geometrical configurations, for both TE and TM polarizations, and in both the subwavelength and non-subwavelength spectral regimes, using the same underlying mechanism and one simple closed-form equation, and does not require explicitly invoking specific polarization dependent mechanisms. The known excitation of surface plasmons polaritons or slit cavity modes, emerge as limiting cases of a more general condition. This equation can be used to easily design and analyze the optical properties of a wide range of rectangular metallic transmission gratings.
我们给出一种直观的推理和推导，得出一个近似的、简单的封闭形式模型，用于预测和解释在各种配置和偏振情况下，通过矩形、光学致密金属光栅增强传输共振的一般出现情况。该模型基于有效折射率近似，它以一种简单的方式统一了作为周期性结构不同衍射级次的驻波共振而出现的增强传输的潜在机制。该模型使用相同的潜在机制和一个简单的封闭形式方程，正确地预测了各种几何配置下TE和TM偏振在亚波长和非亚波长光谱区域中增强传输共振的条件，并且不需要明确调用特定的偏振相关机制。已知的表面等离激元极化激元或狭缝腔模的激发，是更一般条件的极限情况。该方程可用于轻松设计和分析各种矩形金属透射光栅的光学特性。
