Wang Qiao, Kuang Kaili, Gao Huixuan, Chu Shuwen, Yu Li, Peng Wei
Department of Physics, Dalian University of Technology, Ganjingzi District, Dalian 116024, China.
Nanomaterials (Basel). 2021 May 20;11(5):1350. doi: 10.3390/nano11051350.
Electromagnetically induced transparency-like (EIT-like) effect is a promising research area for applications of slow light, sensing and metamaterials. The EIT-like effect is generally formed by the destructive interference of bright-dark mode coupling and bright-bright mode coupling. There are seldom reports about EIT-like effect realized by the coupling of two dark modes. In this paper, we numerically and theoretically demonstrated that the EIT-like effect is achieved through dark-dark mode coupling of two waveguide resonances in a compound nanosystem with metal grating and multilayer structure. If we introduce |1⟩, |2⟩ and |3⟩ to represent the surface plasmon polaritons (SPPs) resonance, waveguide resonance in layer 2, and waveguide resonance in layer 4, the destructive interference occurs between two pathways of |0⟩→|1⟩→|2⟩ and |0⟩→|1⟩→|2⟩→|3⟩→|2⟩, where |0⟩ is the ground state without excitation. Our work will stimulate more studies on EIT-like effect with dark-dark mode coupling in other systems.
类电磁诱导透明（EIT-like）效应是慢光、传感和超材料应用中一个很有前景的研究领域。类EIT效应通常由亮-暗模式耦合和亮-亮模式耦合的相消干涉形成。关于通过两个暗模式耦合实现类EIT效应的报道很少。在本文中，我们通过数值模拟和理论分析证明，在具有金属光栅和多层结构的复合纳米系统中，通过两个波导共振的暗-暗模式耦合实现了类EIT效应。如果我们引入|1⟩、|2⟩和|3⟩来表示表面等离激元极化激元（SPPs）共振、第2层中的波导共振和第4层中的波导共振，那么在|0⟩→|1⟩→|2⟩和|0⟩→|1⟩→|2⟩→|3⟩→|2⟩这两条路径之间会发生相消干涉，其中|0⟩是未被激发的基态。我们的工作将激发更多关于其他系统中暗-暗模式耦合的类EIT效应的研究。
