Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel UMR 7249, 13013 Marseille, France.
Nanoscale. 2016 May 21;8(19):10441-52. doi: 10.1039/c6nr00676k. Epub 2016 May 4.
Chirality of light is of fundamental importance in several enabling technologies with growing applications in life sciences, chemistry and photodetection. Recently, some attention has been focused on chiral quantum emitters. Consequently, optical antennas which are able to tailor the chirality of light emission are needed. Spherical nanoresonators such as colloids are of particular interest to design optical antennas since they can be synthesized at a large scale and they exhibit good optical properties. Here, we show that these colloids can be used to tailor the chirality of a chiral emitter. To this purpose, we derive an analytic formalism to model the interaction between a chiral emitter and a spherical resonator. We then compare the performances of metallic and dielectric spherical antennas to tailor the chirality of light emission. It is seen that, due to their strong electric dipolar response, metallic spherical nanoparticles spoil the chirality of light emission by yielding achiral fields. In contrast, thanks to the combined excitation of electric and magnetic modes, dielectric Si-based particles feature the ability to inhibit or to boost the chirality of light emission. Finally, it is shown that dual modes in dielectric antennas preserve the chirality of light emission.
光的手性在生命科学、化学和光探测等多个新兴应用技术中具有重要意义。最近，人们对手性量子发射器的关注度有所提高。因此，需要能够调整光发射手性的光学天线。球形纳米谐振器（如胶体）是设计光学天线的特别感兴趣的对象，因为它们可以大规模合成，并具有良好的光学性能。在这里，我们展示了这些胶体可以用于调整手性发射器的手性。为此，我们推导出一种解析公式来模拟手性发射器与球形谐振器之间的相互作用。然后，我们比较了金属和介电球形天线的性能，以调整光发射的手性。结果表明，由于金属球形纳米粒子具有强烈的电偶极子响应，它们会产生非手性场，从而破坏光发射的手性。相比之下，由于电和磁模式的联合激发，基于硅的介电粒子具有抑制或增强光发射手性的能力。最后，结果表明介电天线的双模可以保持光发射的手性。
