论文标题
亚波长介电颗粒的多极工程用于散射增强
Multipolar engineering of subwavelength dielectric particles for scattering enhancement
论文作者
论文摘要
亚波长结构上的电磁散射不断吸引由于使用这种现象的可能应用的海外范围而引起的关注。在低对称性谐振器的情况下，散射横截面的基本限制是在球形几何形状中得到充分理解的。在这里，我们修改了超隔离的概念，并将该特性与散射潜力的对称组联系起来。我们演示了谐振器以建设性干扰并增强散射横截面的方式，以频谱重叠的途径重叠。作为一个特别的例子，我们证明了在完全均匀的陶瓷谐振器中，几种电气和磁模式的光谱重叠。优化的结构表明，偶极散射横截面极限的过量，最高为四倍。揭示的规则将对称组与基本散射极限联系起来，可以执行和评估亚波长的散发体的设计，这些设计可以在无标签的成像，紧凑的天线，远程射频频率识别以及许多其他领域中找到使用。
Electromagnetic scattering on subwavelength structures keeps attracting attention owing to abroad range of possible applications, where this phenomenon is in use. Fundamental limits of scattering cross-section, being well understood in spherical geometries, are overlooked in cases of low-symmetry resonators. Here, we revise the notion of superscattering and link this property with symmetry groups of the scattering potential. We demonstrate pathways to spectrally overlap several eigenmodes of a resonator in a way they interfere constructively and enhance the scattering cross-section. As a particular example, we demonstrate spectral overlapping of several electric and magnetic modes in a subwavelength entirely homogeneous ceramic resonator. The optimized structures show the excess of a dipolar scattering cross-section limit for a sphere up to a factor of four. The revealed rules, which link symmetry groups with fundamental scattering limits, allow performing and assessing designs of subwavelength supperscatterers, which can find a use in label-free imaging, compact antennas, long-range radio frequency identification, and many other fields.
