Experimental observation of mode-selective anticrossing in surface-plasmon-coupled metal nanoparticle arrays
Experimental observation of mode-selective anticrossing in surface-plasmon-coupled metal nanoparticle arrays
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DOI：
10.1063/1.3122922
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发表时间：
2009-04
影响因子：
4
通讯作者：
A. Ghoshal;I. Divliansky;P. Kik
中科院分区：
文献类型：
--
作者：
A. Ghoshal;I. Divliansky;P. Kik
实验研究了共振金属纳米粒子对表面等离子激元的激发作用。几何反射测量揭示了几个光学共振的存在。平面内纳米粒子等离子体共振和传播等离子体的强耦合从清晰的抗交叉行为可见一斑。在高数值孔径下的反射测量表明，表面等离子激元是通过面外粒子偏振激发的。这样激发的等离子体激元在所考虑的频率范围内不表现出抗交叉。用已知的表面等离子体色散关系和各向异性频率相关的纳米粒子极化率来解释这些结果。这些发现对于利用表面耦合纳米粒子等离子体共振的应用是重要的。
Surface plasmon excitation using resonant metal nanoparticles is studied experimentally. Geometry dependent reflection measurements reveal the existence of several optical resonances. Strong coupling of the in-plane nanoparticle plasmon resonance and propagating plasmons is evident from clear anticrossing behavior. Reflection measurements at high numerical aperture demonstrate the excitation of surface plasmons via out-of-plane particle polarization. The thus excited plasmons do not exhibit anticrossing in the considered frequency range. The results are explained in terms of the known surface plasmon dispersion relation and the anisotropic frequency dependent nanoparticle polarizability. These findings are important for applications utilizing surface-coupled nanoparticle plasmon resonances.