Influence of aperture shape on the transmission properties of a periodic array of subwavelength apertures
Influence of aperture shape on the transmission properties of a periodic array of subwavelength apertures
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DOI：
10.1364/opex.12.003664
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发表时间：
2004-08-09
期刊：
影响因子：
3.8
通讯作者：
Nahata, A
中科院分区：
文献类型：
--
作者：
Cao, H;Nahata, A
我们证明，与周期性阵列的亚波长孔径的共振增强的透射谱是依赖于孔径的形状。这表明使用相干太赫兹辐射和孔径阵列制作在75 μ m厚的不锈钢箔。我们检查矩形孔不同的纵横比，以及圆形孔。在阵列中不存在周期性的情况下，不存在谐振特征。对于周期性阵列，我们表明，透射系数的比例为两个最低阶谐振可以直接关系到适当的孔径尺寸的比例。从时域波形，我们发现两个独立的，但相位相干，传输过程：非共振传输相关的简单传输通过亚波长孔径和时间延迟的共振传输相关的太赫兹脉冲与周期性孔径阵列的相互作用。在这些波形中，我们还观察到相对于参考的初级双极脉冲的符号反转。这被证明是衍射的一个简单结果。(C)2004年美国光学学会。
We demonstrate that the resonantly enhanced transmission spectrum associated with a periodic array of subwavelength apertures is dependent upon the shape of the apertures. This is demonstrated using coherent terahertz radiation and aperture arrays fabricated in 75 mum thick stainless steel foils. We examine rectangular apertures with different aspect ratios as well as circular apertures. In the absence of periodicity in the arrays, no resonance features are present. For periodic arrays, we show that the ratio of the transmission coefficients for the two lowest order resonances can be directly related to the ratio of the appropriate aperture dimensions. From the time-domain waveforms, we find two independent, yet phase-coherent, transmission processes: non-resonant transmission related to the simple transmission through subwavelength apertures and a time-delayed resonant transmission related to the interaction of the THz pulse with the periodic aperture array. In these waveforms, we also observe a sign inversion for the primary bipolar pulse relative to the reference. This is shown to be a simple consequence of diffraction. (C) 2004 Optical Society of America.