论文标题
理想的Kerker通过同质球散射：增益或损失的作用
Ideal Kerker scattering by homogeneous spheres: the role of gain or loss
论文作者
论文摘要
我们重新检查了最近的一项工作[物理学。莱特牧师。 \ textbf {125}，073205（2020）]研究了光学增益或损失（以各向同性复合物折射率为特征）如何影响零向后散射的理想kerker散射。在那里，严格证明，对于具有入射平面波的非磁性同质球，如果存在特定顺序的电气和磁多物，并且可以将其他多物的贡献完全零。在这里，我们揭示，当固定顺序的两个多物与相位和大小都完美匹配时，至少接下来的两个订单的多物不可能被调谐为完全零甚至完全匹配，因此无法直接产生理想的kerker散射。此外，我们进一步证明，当同时考虑不同阶的多孔时，损失或增益可以作为消除向后散射的有用而不是有害的贡献因素。
We reexamine a recent work [Phys. Rev. Lett. \textbf{125}, 073205 (2020)] that investigates how the optical gain or loss (characterized by isotropic complex refractive indexes) influences the ideal Kerker scattering of exactly zero backward scattering. There it has been rigourously proved that, for non-magnetic homogeneous spheres with incident plane waves, either gain or loss prohibits such ideal Kerker scattering, provided that only electric and magnetic multipoles of a specific order are present and contributions from other multipoles can all be made precisely zero. Here we reveal that, when two multipoles of a fixed order are perfectly matched in terms of both phase and magnitude, multipoles of at least the next two orders cannot possibly be tuned to be all precisely zero or even perfectly matched, and consequently cannot directly produce ideal Kerker scattering. Moreover, we further demonstrate that, when multipoles of different orders are simultaneously taken into consideration, the loss or gain can serve as a helpful rather than harmful contributing factor, for the eliminations of backward scattering.
