We investigate symmetry-selective surface-mode excitation in a general periodically time-modulated double-layer system, where the modulation of the two layers has a constant phase difference. By deriving a semi-analytic transfer matrix formalism of a Drude-dispersive double-layer structure with periodic time-modulation, we calculate the scattering amplitudes and the corresponding transmission coefficient. Our results show that the phase-difference between the modulation of the two sheets plays an essential role in significantly enhancing and selectively exciting either the even or odd surface mode with high efficiency. We verify our calculations with full-wave time-domain simulations, showing that efficient switching between the surface-wave excitation of the two distinct modal channels can be achieved, even under illumination from a single off-resonant Gaussian pulse, by controlling the phase difference between the two modulations. Our results pave the way towards ultrafast, symmetry-selective mode excitation and switching via temporal modulation.

中文翻译：

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支持阶段性时间 Wood 异常的双 Floquet 片中的表面波耦合

我们研究了一般周期性时间调制双层系统中的对称选择性表面模式激发，其中两层的调制具有恒定的相位差。通过推导具有周期性时间调制的德鲁德色散双层结构的半解析传递矩阵形式，我们计算了散射幅度和相应的透射系数。我们的结果表明，两个薄片调制之间的相位差在显着增强和选择性地高效激发偶数或奇数表面模式方面起着至关重要的作用。我们用全波时域模拟验证了我们的计算，表明可以实现两个不同模态通道的表面波激励之间的有效切换，即使在来自单个非谐振高斯脉冲的照明下，通过控制两个调制之间的相位差。我们的结果为通过时间调制实现超快、对称选择性模式激发和切换铺平了道路。