Diabolo Nanoantenna for Enhancing and Confining the Magnetic Optical Field
Diabolo Nanoantenna for Enhancing and Confining the Magnetic Optical Field
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DOI：
10.1021/nl103817f
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发表时间：
2011-03-01
期刊：
影响因子：
10.8
通讯作者：
Fischer, U. C.
中科院分区：
文献类型：
--
作者：
Grosjean, T.;Mivelle, M.;Fischer, U. C.
在这封信中，我们介绍了一种新的纳米天线概念，旨在在光频率范围内产生单个磁热点，从而在低得多的电场背景下限制和增强磁光场。这种纳米天线是将巴比内的原理应用于领结纳米孔而设计的，形状像一个空竹。它与众所周知的领结纳米天线的不同之处在于，相反的一对金属三角形是通过它们的端头电连接的。因此，不是在领结纳米天线的气隙处积聚大电荷密度，从而产生大电场，而是在空竹纳米天线的中心“金属间隙”内产生高光电流密度，从而产生大磁场。第一个纳米空转几何形状的数值模拟结果表明，在波长为2540 nm的纳米天线中心附近的40 × 40 nm区域内，磁场增强了2900倍。
In this Letter, we introduce a new nanoantenna concept aimed at generating a single magnetic hot spot in the optical frequency range, thus confining and enhancing the magnetic optical field on the background of a much lower electric field. This nano antenna, designed by applying Babinet's principle to the bowtie nanoaperture, takes the shape of a diabolo. It differs from the well-known bowtie nanoantenna in that the opposing pair of metal triangles are electrically connected through their facing tips. Thus instead of a large charge density accumulating at the air gap of the bowtie nanoantenna, leading to a large electric field, a high optical current density develops within the central "metal gap" of the diabolo nanoantenna, leading to a large magnetic field. Numerical simulation results on the first nanodiabolo geometries show a 2900-fold enhancement of the magnetic field at a wavelength of 2540 nm, confined to a 40-by-40 nm region near the center of the nanoantenna.