A Terahertz Electronic Source Based on the Spoof Surface Plasmon With Subwavelength Metallic Grating
A Terahertz Electronic Source Based on the Spoof Surface Plasmon With Subwavelength Metallic Grating
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基于亚波长金属光栅欺骗表面等离子体的太赫兹电子源
DOI：
10.1109/tps.2016.2556319
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发表时间：
2016
影响因子：
1.5
通讯作者：
Liu Pu-Kun
中科院分区：
文献类型：
--
作者：
Liu Yong-Qiang;Kong Ling-Bao;Du Chao-Hai;Liu Pu-Kun
提出了一种基于二维亚波长金属光栅欺骗表面等离子体激元（SSP）的太赫兹电子源。采用简化的模式展开法推导了等离子体光栅的SSP色散关系，并利用粒子模拟方法研究了等离子体光栅与电子注之间的耦合和相互作用。结果表明，电子束在光栅表面的位置对输出特性有很大的影响。对于19.15 kV和0.5 A的注入电子束，对于给定的结构，在1 THz附近的频率下，对于电子束到光栅表面的最佳距离，SSP输出功率可以达到22.7 W。此外，还研究了不同电子束参数对输出功率的影响，发现脉冲电子束比连续电子束具有更好的输出功率。对于给定的束流电压，存在一个最佳的工作频率。此外，通过改变光栅结构参数，可以提高输出性能。通过将光栅槽填充因子从0.8降低到0.2，SSP输出功率可以从17.2增加到23.6 W。在相同的电子束流条件下，在最佳工作频率下，采用槽深为76 ~ 56 μm的浅光栅，可以将SSP功率从14 W提高到28.6 W。本文的工作为获得高功率的THz电子源提供了一条新的途径。
A terahertz electronic source based on the spoof surface plasmon (SSP) with 2-D subwavelength metallic grating is presented. The SSP dispersion relation of plasmonic grating is derived by a simplified modal expansion method, and the coupling and interaction between the SSP and the electron beam is studied by particle-in-cell simulation. The results reveal that the output performance highly depends on the location of electron beam from grating surface. For an injected electron beam with 19.15 kV and 0.5 A, the SSP output power can reach 22.7 W for the optimized distance of the beam from the grating surface at a frequency near 1 THz for the given structure. Besides, the influence of different electron beam parameters on output power is also investigated and we find that pulse electron beam is preferable than continuous electron beam for good performance. There is an optimized operation frequency for the given beam voltage. Furthermore, output performance can be improved by changing grating structure parameters. By decreasing the grating groove filling factor from 0.8 to 0.2, the SSP output power can be increased from 17.2 to 23.6 W. The SSP power can also be significantly enhanced from 14 to 28.6 W using shallow grating with a groove depth changing from 76 to 56 μm for the optimized operation frequency with the same electron beam. The present work may provide a new avenue to obtain powerful THz electronic sources.