表面等离激元-光子混合波导中共振能量转移增强  

Enhancement of Resonance Energy Transfer in Surface Plasmon-Photon Hybrid Waveguide

作　　者：刘杰 陈炫任 王小云[1] 黄勇刚[1] Liu jie;Chen Xuanren;Wang Xiaoyun;Huang Yonggang(College of Physics and Electromechanical Engineering,Jishou University,Jishou 416000,Hunan,China)

机构地区：[1]吉首大学物理与机电工程学院,湖南吉首416000

出　　处：《光学学报》2022年第15期121-129,共9页Acta Optica Sinica

基　　金：国家自然科学基金(11964010,11464013,11464014);湖南省自然科学基金(2020JJ4495);湖南省教育厅项目(21A0333);吉首大学研究生科研创新项目(Jdy19040)。

摘　　要：由于表面等离激元-光子混合波导具有较强的局域场增强效应和较长的传输距离,故在微纳光子学中具有广泛的应用。基于有限元方法,系统研究不同尺寸的金属表面等离激元波导-低折射率空隙-矩形介质波导构成的混合波导中两个二能级原子间的共振能量转移(RET)增强特性。利用二维(2D)有限元方法求解波导模式,以获得波导中近似光子并矢格林函数,并将其与严格三维(3D)有限元解进行比较。结果表明,在单模情况下,由波导模式构建的光子并矢格林函数与严格解符合得较好,而其计算量远小于3D有限元方法。借助该2D快速求解方法,在1550 nm波长下,系统研究该波导单模传输所需要的尺寸和不同波导尺寸对RET增强特性的影响。结果表明:介质波导的宽度越窄,单模所允许的高度越高;当波导的宽度增大时,对于较高的介质波导,其传播距离在增大,RET增强因子在减小,而对于较矮的介质波导,其传播距离先增大后减小,RET增强因子急剧减小;随着高度的增加,传播距离先急剧减小后缓慢增大,而RET增强因子先急剧增大后缓慢变化;低折射率空隙越小,传播距离越短,RET增强因子越大。Surface plasmon-photon hybrid waveguides have been widely used in micro-nano photonics due to their strong enhancement effect in the local field and relatively long transmission distance.Based on the finite element method,the enhancement of resonance energy transfer(RET)between two two-level atoms in a hybrid waveguide with different sizes is studied systematically.The hybrid waveguide is composed of a metal surface plasmon waveguide and a rectangular medium waveguide,with a low refractive index gap between them.The waveguide mode is solved by the two-dimensional(2D)finite element method to obtain the approximate photon dyadic Green’s function in the waveguide,and it is compared with the strict three-dimensional(3D)finite element solution.The comparison results prove that for the single mode,the photon dyadic Green’s function constructed by the waveguide mode agrees well with the strict solution.In addition,compared with the 3D finite element method,the 2D finite element method needs much fewer computation resources.With the help of the 2D finite element method,the size required for the single mode transmission at 1550 nm and its effect on the RET enhancement are systematically studied.It is found that a narrower waveguide is accompanied by a higher medium waveguide needed for the single mode transmission.As the waveguide widens,for a higher medium waveguide,its transmission distance increases,and the RET enhancement factor decreases.While for a lower medium waveguide,its transmission distance firstly increases and then decreases,and the RET enhancement factor declines sharply.As the height of the medium waveguide increases,the transmission distance decreases sharply at first and then increases slowly,while the RET enhancement factor increases sharply at first and then changes slowly.Furthermore,the small low refractive index gap is followed by a short transmission distance and a large RET enhancement factor.

关 键 词：集成光学 共振能量转移 光子并矢格林函数 混合波导 单模 

分 类 号：O439[机械工程—光学工程]