Nonlinear Physics Center, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200, Australia.
Nanoscale. 2013 Jul 21;5(14):6395-403. doi: 10.1039/c3nr01291c. Epub 2013 Jun 5.
Fostered by the recent progress of the fields of plasmonics and metamaterials, the seminal topic of light scattering by clusters of nanoparticles is attracting enormous renewed interest gaining more attention than ever before. Related studies have not only found various new applications in different branches of physics and chemistry, but also spread rapidly into other fields such as biology and medicine. Despite the significant achievements, there still exists unsolved but vitally important challenges of how to obtain robust polarisation-invariant responses of different types of scattering systems. In this paper, we demonstrate polarisation-independent responses of any scattering system with a rotational symmetry with respect to an axis parallel to the propagation direction of the incident wave. We demonstrate that the optical responses such as extinction, scattering, and absorption, can be made independent of the polarisation of the incident wave for all wavelengths. Such polarisation-independent responses are proven to be a robust and generic feature that is purely due to the rotational symmetry of the whole structure. We anticipate our finding will play a significant role in various applications involving light scattering such as sensing, nanoantennas, optical switches, and photovoltaic devices.
得益于等离子体学和超材料领域的最新进展，纳米粒子簇光散射这一开创性的主题正在吸引人们前所未有的巨大兴趣。相关研究不仅在物理和化学的不同分支中找到了各种新的应用，而且还迅速扩展到生物学和医学等其他领域。尽管已经取得了重大的成果，但如何获得不同类型散射系统的稳健偏振不变响应仍然存在尚未解决但至关重要的挑战。在本文中，我们证明了具有相对于平行于入射波传播方向的轴的旋转对称性的任何散射系统的偏振无关响应。我们证明，对于所有波长，消光、散射和吸收等光学响应可以不依赖于入射波的偏振。这种偏振无关的响应被证明是一种稳健且通用的特征，这纯粹是由于整个结构的旋转对称性。我们预计我们的发现将在涉及光散射的各种应用中发挥重要作用，例如传感、纳米天线、光开关和光伏器件。
