Phase-controlled propagation of surface plasmons

• 来源期刊: 光：科学与应用（英文版）
• 关键词: FDTD NSOM phased array plasmonic wakes surface plasmons
• 年，卷（期）: 2017,（4）
• 页码范围: 77-85
• 页数: 9页
• 语种: 英文
• DOI: 10.1038/lsa.2017.72

摘要

Directional emission of electromagnetic radiation can be achieved using a properly shaped single antenna or a phased array of individual antennas.Control of the individual phases within an array enables scanning or other manipulations of the emission,and it is this property of phased arrays that makes them attractive in modern systems.Likewise,the propagation of surface plasmons at the interface between metal films and dielectric materials can be determined by shaping the individual surface nanostructures or via the phase control of individual elements in an array of such structures.Here,we demonstrate control of the propagation of surface plasmons within a linear array of nanostructures.The generic situation of plasmonic surface propagation that is different on both sides of a metal film provides a unique opportunity for such control:plasmons propagating on the slower side feed into the side with the faster propagation,creating a phased array of interfering antennas and thus controlling the directionality of the wake fields.We further show that by shaping the individual nanoantennas,we can generate an asymmetric propagation geometry.