具有尖锐吸收截面和显著增强电场的等离激元-光子混合谐振腔  

Hybrid Plasmonic-photonic Resonators with Sharp Absorption Cross-section and Obvious Electric Field Enhancement

作　　者：刘莹[1] 朱泽斌 蒋立勇[1,2] LIU Ying;ZHU Zebin;JIANG Liyong(Institute of Micro-nano Photonics and Quantum Manipulation,School of Physics,Nanjing University of Science and Technology,Nanjing 210094,China;MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学物理学院微纳光子学与量子调控研究所,南京210094 [2]南京理工大学半导体微纳结构与量子信息感知工业和信息化部重点实验室,南京210094

出　　处：《光子学报》2024年第5期215-224,共10页Acta Photonica Sinica

基　　金：National Natural Science Foundation of China(No.61675096);Fundamental Research Funds for the Centre Universities(No.30922010801);Fundamental Research Funds for NUST(No.TSXK2022D006);Postgraduate Research Practice Innovation Program of Jiangsu Province(No.KYCX23_0442)。

摘　　要：研究了由二维光子晶体微腔和金纳米天线组成的等离激元-光子混合谐振腔中光学谐振腔对等离激元谐振腔的额外贡献。研究结果表明:与纯等离激元谐振腔相比,混合体系的吸收截面和电场强度均明显增强。特别地,混合谐振腔的吸收截面谱呈现出类Fano线形和尖峰,可以通过改变金纳米天线的数量或金纳米天线与光子晶体微腔之间的共振波长失谐进行调制。此外,混合谐振腔的电场增强因子比金纳米天线高出3个数量级。可为光热探测和光谱增强研究提供新的平台。In recent years,the plasmonic-photonic hybrid system has attracted extensive attention and research from scholars at home and abroad because of its combination of the advantages of the plasmonic and photonic resonators.In previous works,the plasmonic-photonic hybrid system has demonstrated obviously enhanced Purcell factor due to the deep subwavelength confinement of localized surface plasmon resonance and the additional contribution of the ultra-small mode volume.Different from previous works,in this paper,we are focused on the extra contribution of optical resonator on plasmonic resonator in a plasmonic-photonic hybrid resonator consisting of a two-dimensional photonic crystal microcavity and Au nano-antennas.Firstly,the absorption cross section spectrum and the distribution of electric field intensity of the hybrid resonators are calculated by using the finite difference time domain method.By comparing the coupling characteristics of singe-NA model,three-NAs model and five-NAs model,the physical mechanism of the enhanced absorption cross section and the law of the enhanced electric field intensity are analyzed.The results prove that compared with pure plasmon resonators,the hybrid system demonstrates obviously enhanced absorption cross-section and electric field intensity.In particular,the hybrid resonator exhibits Fano-like lineshape and sharp peak in its absorption cross-section spectrum which can be modulated by changing the numbers of Au nano-antennas or the resonance wavelength detuning between the Au nano-antenna and PC microcavity.With the increase of the number of Au-NAs,the absorption cross section of the hybrid system is continuously enhanced,but the response is different at 657 nm and 576 nm.Due to the increasing loss of the Au NAs,the Fano-like lineshape at 657 nm are getting more and more unconspicuous,while the peaks at 576 nm are becoming sharper,which is due to the superposition of each Au NA coupled with the PC microcavity's higher-order mode at 576 nm.In general,the five-NAs model has the bes

关 键 词：混合谐振腔 尖锐吸收截面 显著增强电场 表面等离激元 光子晶体 

分 类 号：O431.1[机械工程—光学工程]