Tribelsky Michael I, Luk'yanchuk Boris S
Moscow State Institute of Radioengineering, Electronics and Automation (Technical University), 78 Vernadskiy Avenue, Moscow 119454, Russia.
Phys Rev Lett. 2006 Dec 31;97(26):263902. doi: 10.1103/PhysRevLett.97.263902. Epub 2006 Dec 28.
Light scattering by a small spherical particle with a low dissipation rate is discussed based upon the Mie theory. It is shown that if close to the plasmon (polariton) resonance frequencies the radiative damping prevails over dissipative losses, sharp giant resonances with very unusual properties may be observed. In particular, the resonance extinction cross section increases with an increase in the order of the resonance (dipole, quadrupole, etc.); the characteristic values of electric and magnetic near fields for the scattered light are singular in the particle size, while energy circulation in the near field is rather complicated, so that the Poynting vector field includes singular points whose number, types, and positions are very sensitive to fine changes in the incident light frequency. The results may provide new opportunities for a giant, controlled, highly frequency-sensitive enhancement and variation of electromagnetic field at nanoscales.
基于米氏理论，讨论了具有低耗散率的小球形粒子的光散射。结果表明，如果接近等离子体（极化激元）共振频率，辐射阻尼超过耗散损耗，则可能会观察到具有非常特殊性质的尖锐巨共振。特别是，共振消光截面随着共振阶数（偶极、四极等）的增加而增大；散射光的电场和磁场近场的特征值在粒子尺寸上是奇异的，而近场中的能量循环相当复杂，因此坡印廷矢量场包含奇异点，其数量、类型和位置对入射光频率的细微变化非常敏感。这些结果可能为纳米尺度下电磁场的巨大、可控、高频率敏感增强和变化提供新的机会。
