摘要
基于表面等离子激元理论提出一个由金属-介质-金属波导和半环切口组成的波导结构,应用时域有限差分法研究了该结构的透射特性.仿真结果表明:透射光谱中产生一个类似法诺共振线形的共振谷,该法诺共振由半环切口中连续态与离散态的相互干涉所致,其共振波长可以通过改变半环切口的结构参量进行调节,该结构灵敏度约为575nm/RIU,品质因数可达5 671.添加一个矩形谐振腔于该结构上可产生多重法诺共振,品质因数为6 555,此特征能为波导结构的设计提供极大的灵活性,有望在光学集成回路、纳米传感器方面得到比较广泛的应用.
Based on the theory of Surface plasmon polaritons, a plasmonic structure consisting of a metal-insulator-metal waveguide and a semi-ring stub was proposed to investigate the transmission properties by the finite-difference time-domain method. Simulation results show that there is a sharp and asymmetric Fano profile in transmission spectrum, which originates from the interference between a discrete state and a continuous state in the semi-ring stub. The tuning of the Fano profile is realized by changing the size of the semi-ring stub, and the sensitivity and figure of merit of this structure is 575 nm/RIU and 5 671. Moreover, multiple fano resonances are induced by setting a rectangular cavity in the waveguide, a figure of merit as high as 6 555, which offer flexibility in the design of the structure. The waveguide structure may find widespread applications in highly integrated optical circuits, special for nano bio-sensor.
出处
《光子学报》
EI
CAS
CSCD
北大核心
2018年第1期76-83,共8页
Acta Photonica Sinica
基金
The National Natural Science Foundation of China(Nos.61502538,61501525)
the Nature Science Foundation for Young Scientists of Hunan Province,China(No.2015JJ3157)
the Graduate Scientific Research Foundation of Central South University(No.2017zzts699)
关键词
表面等离子激元
纳米传感器
时域有限差分法
法诺共振
半环切口
波导结构
Surface plasmon polaritons
Nano sensor
Finite-difference time-domain method
Fano resonances
Semi-ring stub
Fano resonance
