基于纳米盘棒耦合的多频段等离激元诱导透明研究  

Multiband plasmon-induced transparency based on silver nanorods and nanodisk hybrid model

作　　者：胡宝晶[1,2] 黄铭 黎鹏[1] 杨成福[1] Hu Bao-Jing;Huang Ming;Li Peng;Yang Cheng-Fu(School of Information Science and Engineering,Yunnan University,Kunming 650091,China;College of Science,Yunnan Agricultural University,Kunming 650201,China)

机构地区：[1]云南大学信息学院,昆明650091 [2]云南农业大学理学院,昆明650201

出　　处：《物理学报》2020年第13期93-100,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61461052,11564044,61863035);云南省教育厅科学研究基金(批准号:2019J0172)资助的课题.

摘　　要：提出了基于银纳米棒和银纳米盘的多频段等离激元诱导透明(PIT)混合模型,通过时域有限差分法研究了模型的电磁特性.研究表明:由于银纳米盘(明模)和银纳米棒(暗模)的明模-暗模-暗模耦合,模型可以产生双频段的PIT效应.在双频段的基础之上,通过两个非对称的双频段PIT模型的叠加,形成暗模-暗模-明模-暗模-暗模耦合,可进一步实现四频段的PIT效应.同时,只要改变两种PIT模型中银纳米棒的长度以及银纳米棒和银纳米盘之间的距离,双频段PIT和四频段PIT窗口的谐振频率和透射振幅都会随之变化.最后研究了四频段PIT模型的传感效应,发现该模型随背景材料折射率变化的灵敏度(sensitivity)达到了326.2625 THz/RIU,优值系数(FOM)达到了26.4/RIU,性能优于其他同类型传感器,这为该模型在光存储、吸收、滤波和红外频段的传感器设计中的应用提供了理论参考.In this paper,the dual-band and four-band plamon-induced transparency(PIT)hybrid model based on silver nanorod and silver nanodisk hybrid model are proposed.The electromagnetic characteristics of the two PIT hybrid models are also estimated respectively.The results show that in the double-band PIT model,the silver nanodisk(bright mode)and the silver nanorod(dark mode)can form the bright-dark-dark mode coupling.Because of the destructive interference produced by nanodisk and nanorod and the emergence of new SPs resonance modes between nanorod and nanorod,the double-band PIT model can produce two transparent windows.When the length of the nanorods and the distance between the nanorods and nanodisk are changed,the resonant frequencies and transmission amplitudes of two transparent windows will be changed accordingly.In the four-band PIT model,the silver nanodisk and the silver nanorods will form the dark-dark-brightdark-dark mode coupling.The resonant peaks of four transparent windows almost coincide with those of the two asymmetric double-band PIT models.Therefore,the four-band PIT model can be regarded as the superposition of two asymmetric double-band PIT models.The resonant frequencies and transmission amplitudes of four transparent windows also vary with the the length of nanorods and the distance between nanorods and nanodisk.Finally,the sensing performance of the four-band PIT model is investigated.It is found that the model can produce four transparent windows from beginning to end when the refractive index of the background material is changed.As the refractive index is changed from 1.0 to 1.4,the resonant frequencies in four transparent windows are approximately linearly related to the refractive index.At the same time,the maximum sensitivity of the four transparent windows can reach 326.2625(THz/RIU)and the maximum figure of merit can arrive at 26.4(1/RIU),which is higher than those of similar similar sensors in other literatures.This work provides the theoretical support for these models’potential appl

关 键 词：多频段等离激元诱导透明 超材料 时域有限差分法 

分 类 号：O53[理学—等离子体物理] TP212[理学—物理]