Optical responses of metallic plasmonic arrays under the localized excitation  

作　　者：Sen Yan Hao Ma Yi-Fan Bao Maofeng Cao Chuan Liu Kaifeng Zhang Xiaowei Wu Jianbo He Xiang Wang Bin Ren 

机构地区：[1]State Key Laboratory of Physical Chemistry of Solid Surfaces,Department of Chemistry,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China [2]Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM),Xiamen 361005,China [3]Research&Development Group,Hitachi,Ltd.,Yokohama 244-0817,Kanagawa,Japan [4]Department of Electronic Science and Engineering,Kyoto University,Kyoto 615-8510,Japan

出　　处：《Nano Research》2024年第3期1571-1577,共7页纳米研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.22021001,22227802,22104125,and 92061118);the Fundamental Research Funds for the Central Universities(No.20720220018);the Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM).

摘　　要：The metallic plasmonic array that can support both propagating surface plasmon polaritons(PSPPs)and localized surface plasmon resonance(LSPR)possesses rich optical properties and remarkable optical performance,making it a powerful platform for applications in photonics,chemistry,and materials.For practical applications,the excitation spot is usually smaller than the area of metal arrays.It is thus imperative to address“how many array units are enough?”towards a rational design of plasmonic nanostructures.Herein,we employed focused ion beam(FIB)to precisely fabricate a series of plasmonic array structures with increased unit number.By utilizing photoluminescence(PL)and surface-enhanced Raman spectroscopy(SERS),we found that the array units outside the excitation spot still have a significant impact on the optical response within the spot.Combined with the numerical simulation,we found that the boundary of the finite array leads to the loss of PSPP outside the excitation point,which subsequently affects the coupling of PSPP and LSPR in the excitation spot,leading to variations in PL and SERS intensity.Based on the findings,we further tuned the LSPR mode of the metal arrays by electrodeposition to obtain strong near-field enhancement without any influence on the PSPP mode.This work advances the understanding of near-field and far-field optical behavior in finite-size array structures and provides guidance for designing highly-efficient photonic devices.

关 键 词：plasmonic periodic array finite-size effects dark field scattering surface-enhanced Raman spectroscopy(SERS) 

分 类 号：O43[机械工程—光学工程]