介质加载型表面等离子体波导中发光粒子的自发辐射特性  

Spontaneous Emission Properties of Emitters in Dielectric-Loaded Surface Plasmon Polariton Waveguide

作　　者：姚波 刘晔 龙虎 毛庆和 

机构地区：[1]中国科学院安徽光学精密机械研究所安徽省光子器件重点实验室,安徽合肥230031

出　　处：《光学学报》2015年第8期303-309,共7页Acta Optica Sinica

基　　金：国家973计划(2013CB934304);国家自然科学基金(61377044;61275186;11104282)

摘　　要：研究了介质加载型表面等离子体(DLSPP)波导中发光粒子的自发辐射特性。通过经典偶极子近似,给出了发光粒子在SPP波导任意位置处的自发辐射速率与自发辐射耦合成表面等离子体(SPP)导波模概率的计算方法;采用有限元法(FEM)模拟计算了单模DLSPP波导中若丹明6G(R6G)发光粒子的自发辐射速率和自发辐射耦合成SPP模式的概率。模拟结果表明,在DLSPP波导中,当发光粒子距金属界面较近时,自发辐射速率大幅增强,当远离金属界面时,自发辐射速率降低并趋于真空中的值;同时,DLSPP波导中发光粒子自发辐射耦合成SPP模式的概率也与其位置相关,当处在波导截面中心位置时,自发辐射耦合成SPP导波模的概率可高达70%。基于上述模拟结果,指出通过优化发光粒子在截面上的掺杂分布,可以提高截面上平均粒子数反转度,也可以提高截面上发光粒子自发辐射耦合成SPP导波模的总效率。The spontaneous emission properties of emitters in dielectric-loaded surface plasmon polariton （DLSPP） waveguide are investigated. The expressions for both the spontaneous emission rate and the probability of spontaneous emission coupled into SPP mode of an emitter in SPP waveguide are derived with a dipole approximation. Then, the spontaneous emission rate and the probability of spontaneous emission coupled into SPP mode of the rhodamine 6G （R6G） particle in the single-mode DLSPP waveguide are calculated numerically. The results show that the spontaneous emission rate of the particle increases when the particle is near the metal interface while decreases and inclines to the value in the vacuum when the particle is away from the metal interface. Meanwhile, the probability of spontaneous emission coupled into SPP mode is also position-related, and may reach about 70% when the particle is located in the center part of the cross-sectional area of the waveguide. With those simulation results, it may be predicted that both the maximum achievable average population inversion and the efficiency of spontaneous emission coupled into SPP mode of the particles over the cross-sectional area of the waveguide may be improved by optimizing the particle-doped distribution.

关 键 词：激光光学 表面等离子体波导 自发辐射 偶极子 若丹明6G 

分 类 号：TN201[电子电信—物理电子学]