Controlling the radiation direction of propagating surface plasmons on silver nanowires

• Published in: Laser & photonics reviews Vol. 8; no. 4; pp. 596 - 601
• Main Authors: Wang, Zhuoxian, Wei, Hong, Pan, Deng, Xu, Hongxing
• Format: Journal Article
• Language: English
• Published: Weinheim Blackwell Publishing Ltd 01.07.2014; Wiley Subscription Services, Inc
• Subjects: Aluminum oxide; Dielectrics; Fourier imaging; leakage radiation; Nanostructure; Nanowires; Plasmons; propagating surface plasmons; Propagation; Silver; silver nanowire; Spark plasma sintering
• ISSN: 1863-8880; 1863-8899
• DOI: 10.1002/lpor.201300215

Metal nanowires supporting propagating surface plasmons (SPs) can be used as nanowaveguides and nanoantennas for light manipulation beyond the diffraction limit. Here the control of the propagation and radiation of SPs on silver nanowires is investigated. By covering an Al2O3 layer onto a silver nanowire to change the local dielectric environment, the wave vector of the propagating SPs is increased. Thus, the radiation direction of SPs into the substrate is changed according to the phase matching condition, which is experimentally shown by Fourier imaging method. The radiation angle is sensitively dependent on the Al2O3 thickness. By depositing 1 nm Al2O3, the increase of the radiation angle can be close to 1 degree. These results show that dielectric‐layer‐coating provides a simple and effective method to control the propagation and radiation of SPs, which will be of great importance for designing plasmonic circuits, antennas and sensors based on silver nanowires. Metal nanowires supporting propagating surface plasmons (SPs) can be used as nanowaveguides and nanoantennas for light manipulation beyond the diffraction limit. Here the control of the propagation and radiation of SPs on silver nanowires is investigated. By covering an Al2O3 layer onto a silver nanowire to change the local dielectric environment, the wave vector of the propagating SPs is increased. Thus, the radiation direction of SPs into the substrate is changed according to the phase matching condition, which is experimentally shown by Fourier imaging method. The radiation angle is sensitively dependent on the Al2O3 thickness. By depositing 1 nm Al2O3, the increase of the radiation angle can be close to 1 degree. These results show that dielectric‐layer‐coating provides a simple and effective method to control the propagation and radiation of SPs, which will be of great importance for designing plasmonic circuits, antennas and sensors based on silver nanowires.