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Controlling the radiation direction of propagating surface plasmons on silver nanowires
Author(s) -
Wang Zhuoxian,
Wei Hong,
Pan Deng,
Xu Hongxing
Publication year - 2014
Publication title -
laser and photonics reviews
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.778
H-Index - 116
eISSN - 1863-8899
pISSN - 1863-8880
DOI - 10.1002/lpor.201300215
Subject(s) - materials science , plasmon , nanowire , surface plasmon , optics , radiation , diffraction , optoelectronics , dielectric , layer (electronics) , substrate (aquarium) , nanotechnology , physics , oceanography , geology
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 Al 2 O 3 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 Al 2 O 3 thickness. By depositing 1 nm Al 2 O 3 , 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.