Reverse surface-polariton cherenkov radiation.
Reverse surface-polariton cherenkov radiation.
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DOI：
10.1038/srep30704
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发表时间：
2016-08-01
影响因子：
4.6
通讯作者：
Luo Y
中科院分区：
文献类型：
--
作者：
Tao J;Wang QJ;Zhang J;Luo Y
用解析的方法证明了表面等离子体逆切伦科夫辐射的存在。结果表明，在金属-绝缘体-金属(MIM)光波导中，当电子以高于表面等离子体极化子相速度的速度运动时，表面等离子体极化子(SPPs)会产生切伦科夫辐射，并可通过调节波导的芯层厚度从正向切换到反向。从频域和时间域两个方面进行了计算，结果表明，在较小的波导芯宽度下，可以获得具有后向辐射锥的辐射方向图，其能量流与表面等离子体波的波矢方向相反。我们的研究表明，在简单的等离子体系统中产生和引导电子辐射是可行的，为各种应用打开了大门，例如速度选择粒子探测。
The existence of reverse Cherenkov radiation for surface plasmons is demonstrated analytically. It is shown that in a metal-insulator-metal (MIM) waveguide, surface plasmon polaritons (SPPs) excited by an electron moving at a speed higher than the phase velocity of SPPs can generate Cherenkov radiation, which can be switched from forward to reverse direction by tuning the core thickness of the waveguide. Calculations are performed in both frequency and time domains, demonstrating that a radiation pattern with a backward-pointing radiation cone can be achieved at small waveguide core widths, with energy flow opposite to the wave vector of SPPs. Our study suggests the feasibility of generating and steering electron radiation in simple plasmonic systems, opening the gate for various applications such as velocity-selective particle detections.