Revealing the plasmon coupling in gold nanochains directly from the near field  

作　　者：Quan Sun Han Yu Kosei Ueno Shuai Zu Yasutaka Matsuo Hiroaki Misawa 

机构地区：[1]Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan [2]College of Electronic Science and Engineering, Jilin University, Changchun 130012, China

出　　处：《Opto-Electronic Advances》2019年第4期1-7,共7页光电进展（英文）

基　　金：Grants-in-Aid for Scientific Research(Grant Nos.JP18H05205,JP17H01041,JP17H05245,and JP17H05459);We acknowledge the support from the Nanotechnology Platform(Hokkaido University)and Dynamic Alliance for Open Innovation Bridging Human,Environment and Materials(Five-Star Alliance)of MEXT.Q;Sun also acknowledges the support from the National Natural Science Foundation of China(NSFC)(No.11527901).

摘　　要：We studied the near-field properties of localized surface plasmon resonances in finite linear gold nanochains using photoemission electron microscopy(PEEM).The localization of the electromagnetic field in the near-field region was mapped at high spatial resolution.By tuning the excitation laser wavelength,we can obtain the near-field spectra,from which the energy splitting between longitudinal(L)and transverse(T)plasmon modes can be revealed.In particular,the L-mode red shifts and the T-mode blue shifts with increasing chain length.The red shift of the L-mode is highly dependent on the gap distance.In contrast,the T-mode almost remains constant within the range of gap distance we investigated.This energy splitting between the L-mode and the T-mode of metallic chains is in agreement with previous far-field measurements,where it was explained by dipole-dipole near-field coupling.Here,we provide direct proof of this near-field plasmon coupling in nanochains via the above-described near-field measurements using PEEM.In addition,we explore the energy transport along the gold nanochains under excitation at oblique illumination via PEEM measurements together with numerical simulations.

关 键 词：surface PLASMON RESONANCE metallic nanochains NEAR-FIELD imaging PHOTOEMISSION electron MICROSCOPY 

分 类 号：TN[电子电信]