Chen Dingwei, Takahara Junichi
Opt Lett. 2025 Jul 1;50(13):4246-4249. doi: 10.1364/OL.562981.
Excitons in two-dimensional (2D) transition metal dichalcogenides are essential in optical responses. However, the absorption intensity remains limited at room temperature. This study presents a Huygens Si metasurface (MS) platform to enhance WS excitonic absorption via coherent coupling and degenerate critical coupling (DCC), achieving near-unity total absorption up to 0.90. Different Mie modes contributed to this enhancement, originating from distinct physical effects. Notably, we demonstrated Miexcitons and observed an anticrossing phenomenon between the excitons and electric dipole (ED) mode induced by the coherent coupling. The intensity of the coherent coupling was significantly amplified by the DCC, resulting in an 18-fold increase in WS absorption compared to that on a Si substrate. This platform provides a promising approach for advancing light-exciton interactions and the development of optical devices using 2D semiconductors.
二维（2D）过渡金属二硫属化物中的激子对光学响应至关重要。然而，在室温下吸收强度仍然有限。本研究提出了一种惠更斯硅超表面（MS）平台，通过相干耦合和简并临界耦合（DCC）增强WS激子吸收，实现高达0.90的近单位总吸收。不同的米氏模式促成了这种增强，源于不同的物理效应。值得注意的是，我们展示了米氏激子，并观察到由相干耦合诱导的激子与电偶极子（ED）模式之间的反交叉现象。DCC显著放大了相干耦合强度，导致WS吸收比在硅衬底上增加了18倍。该平台为推进光激子相互作用以及使用二维半导体的光学器件开发提供了一种有前景的方法。
