Flexible manipulation of plasmon dephasing time via the adjustable Fano asymmetric dimer  

作　　者：YANG XU YULU QIN PENG LANG BOYU JI XIAOWEI SONG JINGQUAN LIN 

机构地区：[1]School of Science,Changchun University of Science and Technology,Changchun 130022,China [2]State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter,Department of Physics,Peking University,Beijing 100871,China

出　　处：《Photonics Research》2022年第10期2267-2277,共11页光子学研究（英文版）

基　　金：National Natural Science Foundation of China(12004052,61775021,62005022,91850109);111 Project(D17017);Jilin Provincial Key Laboratory of Ultrafast and Extreme Ultraviolet Optics(YDZJ202102CXJD028);Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing,Changchun University of Science and Technology.

摘　　要：It is highly desirable to flexibly and actively manipulate the dephasing time of a plasmon in many potential applications;however,this remains a challenge.In this work,by using femtosecond time-resolved photoemission electron microscopy,we experimentally demonstrated that the Fano resonance mode in the asymmetric nanorod dimer can greatly extend the dephasing time of a femtosecond plasmon,whereas the non-Fano resonance results in a smaller dephasing time due to the large radiative damping,and flexible manipulation of the dephasing time can be realized by adjusting one of the nanorods in the Fano asymmetric dimer.Interestingly,it was found that plasmon resonance wavelengths both appeared red-shifted as the length of the upper or lower nanorods increased individually,but the dephasing time varied.Furthermore,it also indicated that the dephasing time can be prolonged with a smaller ascending rate by increasing the length of both the nanorods simultaneously while keeping the dimer asymmetry.Meanwhile,the roles of radiative and nonradiative damping in dephasing time are unveiled in the process of nanorod length variation.These results are well supported by numerical simulations and calculations.

关 键 词：ASYMMETRIC DIMER RADIATIVE 

分 类 号：O53[理学—等离子体物理]