Nonlinear Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra, ACT, Australia.
Opt Lett. 2013 Jul 15;38(14):2621-4. doi: 10.1364/OL.38.002621.
We study the scattering of normally incident waves by core-shell nanowires, which support both electric and magnetic resonances. Within such nanowires, for p-polarized incident waves, each electric resonance corresponds to two degenerate scattering channels while the magnetic resonance corresponds to only one channel. Consequently, when the electric dipole (ED) and magnetic dipole (MD) are tuned to overlap spectrally, the magnitude of the ED is twice that of the magnetic one, leading to a pair of angles of vanishing scattering. We further demonstrate that the scattering features of nanowires are polarization dependent, and vanishing scattering angles also can be induced by Fano resonances due to the interference of higher-order electric modes with the broad MD mode.
我们研究了支持电和磁共振的核壳纳米线对法向入射波的散射。在这种纳米线中，对于 p 偏振入射波，每个电共振对应两个简并散射通道，而磁共振对应只有一个通道。因此，当电偶极子（ED）和磁偶极子（MD）调谐到光谱重叠时，ED 的幅度是 MD 的两倍，导致一对散射角为零。我们进一步证明了纳米线的散射特征是偏振相关的，由于高阶电模与宽 MD 模的干涉，也可以通过 Fano 共振诱导散射角为零。
