Arslan Dennis, Rahimzadegan Aso, Fasold Stefan, Falkner Matthias, Zhou Wenjia, Kroychuk Maria, Rockstuhl Carsten, Pertsch Thomas, Staude Isabelle
Institute of Solid State Physics, Friedrich Schiller University Jena, 07743, Jena, Germany.
Institute of Applied Physics, Abbe Center of Photonics, Friedrich Schiller University Jena, 07745, Jena, Germany.
Adv Mater. 2022 Feb;34(5):e2105868. doi: 10.1002/adma.202105868. Epub 2021 Dec 17.
Conventional optical diffusers, such as thick volume scatterers (Rayleigh scattering) or microstructured surface scatterers (geometric scattering), lack the potential for on-chip integration and are thus incompatible with next-generation photonic devices. Dielectric Huygens' metasurfaces, on the other hand, consist of 2D arrangements of resonant dielectric nanoparticles and therefore constitute a promising material platform for ultrathin and highly efficient photonic devices. When the nanoparticles are arranged in a random but statistically specific fashion, diffusers with exceptional properties are expected to come within reach. This work explores how dielectric Huygens' metasurfaces can implement wavelength-selective diffusers with negligible absorption losses and nearly Lambertian scattering profiles that are largely independent of the angle and polarization of incident waves. The combination of tailored positional disorder with a carefully balanced electric and magnetic response of the nanoparticles is shown to be an integral requirement for the operation as a diffuser. The proposed metasurfaces' directional scattering performance is characterized both experimentally and numerically, and their usability in wavefront-shaping applications is highlighted. Since the metasurfaces operate on the principles of Mie scattering and are embedded in a glassy environment, they may easily be incorporated in integrated photonic devices, fiber optics, or mechanically robust augmented reality displays.
传统的光学漫射器，如厚体散射体（瑞利散射）或微结构表面散射体（几何散射），缺乏片上集成的潜力，因此与下一代光子器件不兼容。另一方面，介电惠更斯超表面由谐振介电纳米粒子的二维排列组成，因此构成了用于超薄高效光子器件的有前途的材料平台。当纳米粒子以随机但统计上特定的方式排列时，具有特殊性能的漫射器有望实现。这项工作探索了介电惠更斯超表面如何实现具有可忽略吸收损耗和几乎朗伯散射分布的波长选择性漫射器，该分布在很大程度上与入射波的角度和偏振无关。定制的位置无序与纳米粒子精心平衡的电和磁响应的结合被证明是作为漫射器运行的一个不可或缺的要求。所提出的超表面的定向散射性能通过实验和数值进行了表征，并突出了它们在波前整形应用中的可用性。由于超表面基于米氏散射原理运行并嵌入玻璃环境中，它们可以很容易地集成到集成光子器件、光纤或机械坚固的增强现实显示器中。
