Comprehensive analysis of photonic nanojets in 3D dielectric cuboids excited by surface plasmons
Comprehensive analysis of photonic nanojets in 3D dielectric cuboids excited by surface plasmons
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DOI：
10.1002/andp.201600098
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发表时间：
2016-10-01
影响因子：
2.4
通讯作者：
Beruete, Miguel
中科院分区：
文献类型：
--
作者：
Pacheco-Pena, Victor;Minin, Igor V.;Beruete, Miguel
在本文中，我们研究了在通信波长的表面等离子体激元的三维介质长方体中的光子纳米射流（PNJ）的激发。使用有效折射率方法进行分析。结果表明，为了在长方体的输出处产生射流，有和没有长方体的区域之间的折射率对比度应大致小于2。当长方体的高度为160 nm时，在λ（0）= 1550 nm处获得最佳性能，在输出界面处产生具有0.68 λ（0）的亚波长分辨率和焦点处的高强度增强（x5）的射流。还研究了多波长响应，表明可以在不同波长处使用所提出的结构。最后，通过在PNJ区域内插入金属颗粒来数值评估后向散射增强，对于半径为0.1 λ（0）的金球，证明了类似于2.44 dB的最大值。
In this paper we study the excitation of photonic nanojets (PNJ) in 3D dielectric cuboids by surface plasmons at telecommunication wavelengths. The analysis is done using the effective refractive index approach. It is shown that the refractive index contrast between the regions with and without cuboid should be roughly less than 2 in order to generate jets at the output of the cuboid. The best performance at lambda(0) = 1550 nm is obtained when the height of the cuboid is 160 nm producing a jet just at the output interface with a subwavelength resolution of 0.68 lambda(0) and a high intensity enhancement (x5) at the focus. The multi-wavelength response is also studied demonstrating that it is possible to use the proposed structure at different wavelengths. Finally, the backscattering enhancement is numerically evaluated by inserting a metal particle within the PNJ region, demonstrating a maximum value of similar to 2.44 dB for a gold sphere of radius 0.1 lambda(0).