Opt Lett. 2019 Mar 15;44(6):1508-1511. doi: 10.1364/OL.44.001508.
Today, nanophotonics still lacks components for modulation that can be easily implementable in existing silicon-on-insulator (SOI) technology. Chalcogenide phase change materials (PCMs) are promising candidates for tuning in the near infrared: at the nanoscale, thin layers can provide enough contrast to control the optical response of a nanostructure. Moreover, all-dielectric metamaterials allow for resonant behavior without having ohmic losses in the telecom range. Here, a novel hybridization of a SOI-based metamaterial with PCM GeTe is experimentally investigated. A metamaterial based on Si nanorods, covered by a thin layer of GeTe, is designed and fabricated. Switching GeTe from amorphous to crystalline leads to a rather high resonance-governed reflection contrast at 1.55 μm. Additional confocal Raman imaging is done to differentiate the crystallized zones of the metamaterials' unit cell. The findings are in good agreement with numerical analysis and show good perspectives of all-dielectric tunable near-infrared nanophotonics.
如今，纳米光子学仍然缺乏可在现有的绝缘体上硅（SOI）技术中轻松实现的调制组件。硫属相变材料（PCM）是在近红外波段调谐的有前途的候选材料：在纳米尺度上，薄的层可以提供足够的对比度来控制纳米结构的光学响应。此外，全电介质超材料允许在电信范围内没有欧姆损耗的共振行为。在这里，实验研究了基于 SOI 的超材料与 PCM GeTe 的新型杂化。设计并制造了一种基于 Si 纳米棒的超材料，其表面覆盖有一层薄薄的 GeTe。将 GeTe 从非晶态切换到晶态会导致在 1.55μm 处产生相当高的共振控制反射对比度。还进行了共焦拉曼成像以区分超材料单元的结晶区域。研究结果与数值分析吻合较好，为全电介质可调谐近红外纳米光子学展现了良好的前景。
