Department of Engineering Physics, École Polytechnique de Montréal, C.P. 6079, Succ. Centre-Ville, Montréal, Québec, H3C 3A7, Canada.
IHP-Leibniz-Institut für innovative Mikroelektronik, Im Technologiepark 25, 15236, Frankfurt (Oder), Germany.
Adv Mater. 2023 Jul;35(28):e2300595. doi: 10.1002/adma.202300595. Epub 2023 May 26.
The short-wave infrared (SWIR) is an underexploited portion of the electromagnetic spectrum in metasurface-based nanophotonics despite its strategic importance in sensing and imaging applications. This is mainly attributed to the lack of material systems to tailor light-matter interactions in this range. Herein, this limitation is addressed and an all-dielectric silicon-integrated metasurface enabling polarization-induced Fano resonance control at SWIR frequencies is demonstrated. The platform consists of a 2D Si/Ge Sn core/shell nanowire array on a silicon wafer. By tuning the light polarization, it is shown that the metasurface reflectance can be efficiently engineered due to Fano resonances emerging from the electric and magnetic dipoles competition. The interference of optically induced dipoles in high-index nanowire arrays offers additional degrees of freedom to tailor the directional scattering and the flow of light while enabling sharp polarization-modulated resonances. This tunablity is harnessed in nanosensors yielding an efficient detection of 10 changes in the refractive index of the surrounding medium.
短波长红外（SWIR）是在基于超表面的纳米光子学中未被充分利用的电磁频谱部分，尽管它在传感和成像应用中具有战略重要性。这主要归因于缺乏在该范围内调整光物质相互作用的材料系统。本文解决了这一限制，并展示了一种全介质硅集成超表面，能够在 SWIR 频率下控制偏振诱导的 Fano 共振。该平台由硅片上的二维 Si/Ge Sn 核/壳纳米线阵列组成。通过调整光偏振，可以证明由于电偶极子和磁偶极子竞争产生的 Fano 共振，超表面反射率可以得到有效控制。在高折射率纳米线阵列中，光诱导偶极子的干涉提供了额外的自由度，可以调整光的方向散射和流动，同时实现尖锐的偏振调制共振。这种可调性在纳米传感器中得到了利用，能够有效检测周围介质折射率的 10 变化。
