Anisotropic Surface Plasmon Polariton Generation Using Bimodal V-Antenna Based Metastructures

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• 作者：Daniel WintzAntonio Ambrosio ; Alexander Y. Zhu ; Patrice Genevet ; Federico Capasso
• 刊名：ACS Photonics
• 出版年：2017
• 出版时间：January 18, 2017
• 年：2017
• 卷：4
• 期：1
• 页码：22-27
• 全文大小：522K
• ISSN：2330-4022

文摘

V-shaped nanoantennas are among the popular choices for the unit element of a metasurface, a nanostructured surface used for its ability to mold and control the wavefront of light. In general, the motivation for choosing the V-antenna as the unit element comes from its bimodal nature, where the introduction of the second mode offers extra control over the scattered wavefronts. Here, through near-field scanning optical microscopy, we study a 1D metastructure comprised of V-antennas in the context of generating asymmetric surface plasmon polariton (SPP) wavefronts. The key point is that the use of the V-antenna allows for the creation of a two-dimensional phase gradient with a single line of antennas, where the extra phase dimension offers additional control and allows for asymmetric features. Two different asymmetries are created: (1) SPP wavefronts that have different propagation directions on either side of the metastructure, and (2) SPP wavefront asymmetry through focusing: one side of the metastructure focuses SPP wavefronts, while the other side has diverging SPP wavefronts.