Metasurfaces are becoming a flourishing field of research, with diverse applications, such as planar optical components and structural colors. While metallic metasurfaces are typically few tens of nanometers in their thickness, their dielectric counterparts typically span few hundreds of nanometers in thickness variations. This makes the stacking of multilayers a bit challenging. To mitigate this challenge, we have developed a new approach for the realization of dielectric metasurfaces. Our approach is based on the nanoscale local oxidation of silicon (LOCOS), allowing to achieve planar metasurface structures. We have utilized this approach for the design, fabrication and characterization of amorphous silicon based all-dielectric Huygens metasurfaces. These metasurfaces show clear electric and magnetic resonances, which can be structurally tuned. The obtained results are in good agreement with numerical simulations taking into account the unique shape of the nanoantennas. Relying on a robust approach for their realization, and combined with the important feature of in situ planarization, we believe that such planarized metasurfaces will become a viable technology for future applications.

中文翻译：

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硅的纳米级局部氧化对惠更斯表面的原位平面化

超表面正成为一个蓬勃发展的研究领域，具有各种应用，例如平面光学组件和结构颜色。虽然金属超表面的厚度通常只有几十纳米，但它们对应的介电层的厚度变化通常只有几百纳米。这使得多层的堆叠有点挑战。为了缓解这一挑战，我们开发了一种实现介电超表面的新方法。我们的方法基于硅的纳米级局部氧化（LOCOS），可实现平面超表面结构。我们已经将这种方法用于基于非晶硅的全介电惠更斯超表面的设计，制造和表征。这些超表面显示出清晰的电和磁共振，可以在结构上进行调整。考虑到纳米天线的独特形状，获得的结果与数值模拟非常吻合。依靠可靠的实现方法，并结合原位平面化的重要功能，我们相信，这种平面化的超颖表面将成为未来应用的可行技术。