Yan Jiahao, Zheng Zhaoqiang, Lou Zaizhu, Li Juan, Mao Bijun, Li Baojun
Institute of Nanophotonics, Jinan University, Guangzhou 511443, China.
School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China.
Nanoscale Horiz. 2020 Sep 28;5(10):1368-1377. doi: 10.1039/d0nh00189a.
Coupling between nanostructures and excitons has attracted great attention for potential applications in quantum information technology. Compared with plasmonic platforms, all-dielectric nanostructures with Mie resonances are more practical because of low-loss, low-cost and CMOS compatibility. However, weak field enhancements in single element dielectric nanostructures hinder their applications in both strong and weak coupling regimes. The Kerker effect arising from the far-field electro-magnetic interactions in dielectric nanostructures brings a new mechanism to realize effective coupling with excitons. Until now, it still remains unsolved whether effective Mie-exciton coupling can be realized based on pure far-field Kerker effect. Therefore, we proposed a silicon-on-insulator (SOI) integrated Mie resonator with a 135 nm top oxide layer to exclude the near-field coupling between excitons and silicon (Si) nanostripes. Through tuning the widths of Si nanostripes to obtain highly directional photoluminescence (PL) emission under Kerker conditions, strong PL enhancements can be observed, whose enhancement factors are comparable to the reported best performances of single all-dielectric or even plasmonic nanostructures coupling with 2D excitons. Our findings bring new strategies for strong light-matter interactions with near-zero heating loss and make it possible to construct 2D materials-silicon hybrid integration for future nanophotonic and optoelectronic devices.
纳米结构与激子之间的耦合因其在量子信息技术中的潜在应用而备受关注。与等离子体平台相比，具有米氏共振的全介质纳米结构由于低损耗、低成本和CMOS兼容性而更具实用性。然而，单元素介电纳米结构中较弱的场增强阻碍了它们在强耦合和弱耦合 regime 中的应用。介电纳米结构中由远场电磁相互作用产生的克尔效应带来了一种实现与激子有效耦合的新机制。到目前为止，基于纯远场克尔效应是否能实现有效的米氏激子耦合仍未得到解决。因此，我们提出了一种具有135nm顶部氧化层的绝缘体上硅（SOI）集成米氏谐振器，以排除激子与硅（Si）纳米条纹之间的近场耦合。通过调整Si纳米条纹的宽度以在克尔条件下获得高度定向的光致发光（PL）发射，可以观察到强烈的PL增强，其增强因子与报道的单个全介质甚至等离子体纳米结构与二维激子耦合的最佳性能相当。我们的发现为具有近零热损耗的强光-物质相互作用带来了新策略，并使得构建用于未来纳米光子和光电器件的二维材料-硅混合集成成为可能。
