Dual-channel rainbow trapping of terahertz surface plasmon-polariton in graded metallic grating structures
Dual-channel rainbow trapping of terahertz surface plasmon-polariton in graded metallic grating structures
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DOI：
10.1080/09500340.2014.944235
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发表时间：
2014-10
影响因子：
1.3
通讯作者：
Yun Shen;Xiaohua Deng;Jiwu Fu;Guoping Wang
中科院分区：
文献类型：
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作者：
Yun Shen;Xiaohua Deng;Jiwu Fu;Guoping Wang
我们数值计算表明，减慢，甚至停止太赫兹波可以实现在一维梯度光栅深度的金属结构。由于色散曲线取决于渐变光栅深度，因此不同波长的波可以定位在结构的不同空间位置，从而导致彩虹捕获。特别地，在所分析的频率范围内，色散曲线上出现两个带，因此在单个结构中可以实现具有不同模式的双通道捕获彩虹。另外，由于不同阶次模的频带在频域上互不重叠，对于每种模，通过适当选择工作频率，都可以实现其单模传播。对于传统的介质或金属波导，这种现象从未发生过。
We numerically show that slowing down and even stopping Terahertz waves can be achieved in a one-dimensional graded-grating-depth metal structure. Since the dispersion curves are dependent on the graded grating depths, waves of different wavelengths can be localized at different spatial positions of the structure, leading to rainbow trapping. Especially, dual-channel trapped rainbows with different modes can be realized in a single structure as two bands appear in the dispersion curve within the analyzed frequency range. In addition, due to the fact that the bands with different order modes do not overlap one another in the frequency domain, for each mode, its single-mode propagation can be available by properly choosing operation frequency. Such a phenomenon never happens for conventional dielectric or metal waveguides.