论文标题
小物体的等离子和介电模式的共振频率和辐射Q因子
Resonance frequency and radiative Q-factor of plasmonic and dielectric modes of small objects
论文作者
论文摘要
非磁性物体的电磁散射共振，如果麦克斯韦方程为负，或者如果磁性质量估计值是积极的，则可以用真空中的入射波长小得多，可以通过麦克斯韦方程的电质量近似来描述。然而，当对象的大小与操作波长相当时，这两个近似值无法正确解释频移和辐射扩大。在此手稿中，得出了对任意形状对象的电QuaSistatic和磁性共振的辐射校正，这仅取决于准居性电流模式。然后，引入了小物体的等离子和介电模式的频率变速和辐射Q因子的封闭形式表达式，其中对物体的材料和大小的依赖性进行了分解。特别是，辐射Q因子明确取决于准模式的多极分量。
The electromagnetic scattering resonances of a non-magnetic object much smaller than the incident wavelength in vacuum can be either described by the electroquasistatic approximation of the Maxwell's equations if its permittivity is negative, or by the magnetoquasistatic approximation if its permittivity is positive and sufficiently high. Nevertheless, these two approximations fail to correctly account for the frequency shift and the radiative broadening of the resonances when the size of the object becomes comparable to the wavelength of operation. In this manuscript, the radiation corrections to the electroquasistatic and magnetoquasistatic resonances of arbitrarily-shaped objects are derived, which only depend on the quasistatic current modes. Then, closed form expressions of the frequency-shift and the radiative Q-factor of both plasmonic and dielectric modes of small objects are introduced, where the dependencies on the material and the size of the object are factorized. In particular, it is shown that the radiative Q-factor explicitly depends on the multipolar components of the quasistatic modes.
