Benetou M I, Bouillard J-S, Segovia P, Dickson W, Thomsen B C, Bayvel P, Zayats A V
Optical Networks Group, Department of Electronic and Electrical Engineering, University College London, London WC1E 7JE, UK.
Nanotechnology. 2015 Nov 6;26(44):444001. doi: 10.1088/0957-4484/26/44/444001. Epub 2015 Oct 15.
Plasmonic crystals, which consist of periodic arrangements of surface features at a metal-dielectric interface, allow the manipulation of optical information in the form of surface plasmon polaritons. Here we investigate the excitation and propagation of plasmonic beams in and around finite size plasmonic crystals at telecom wavelengths, highlighting the effects of the crystal boundary shape and illumination conditions. Significant differences in broad plasmonic beam generation by crystals of different shapes are demonstrated, while for narrow beams, the propagation from a crystal onto the smooth metal film is less sensitive to the crystal boundary shape. We show that by controlling the boundary shape, the size and the excitation beam parameters, directional control of propagating plasmonic modes and their behaviour such as angular beam splitting, focusing power and beam width can be efficiently achieved. This provides a promising route for robust and alignment-independent integration of plasmonic crystals with optical communication components.
等离子体晶体由金属-电介质界面处表面特征的周期性排列组成，能够以表面等离激元极化激元的形式操控光学信息。在此，我们研究了电信波长下有限尺寸等离子体晶体内部及周围等离子体光束的激发与传播，着重突出了晶体边界形状和照明条件的影响。结果表明，不同形状的晶体在产生宽等离子体光束方面存在显著差异，而对于窄光束，从晶体传播到光滑金属膜上的过程对晶体边界形状的敏感度较低。我们发现，通过控制边界形状、尺寸和激发光束参数，可以有效地实现对传播等离子体模式及其行为（如角向光束分裂、聚焦能力和光束宽度）的方向控制。这为等离子体晶体与光通信组件进行稳固且无需对准的集成提供了一条很有前景的途径。
