Abstract-Strong slow-light effect for a hexagonal graphene coupled metasurface in terahertz

 

Wei Cui, Yixuan Wang, Zhihui He, Hui He, 

https://www.sciencedirect.com/science/article/pii/S2211379721004824

Exploring higher group index has great benefits in the application of plasmonic slow-light devices. A hexagonal graphene coupled metasurface is proposed for realizing dual plasma induced transparency(dual-PIT) in terahertz through finite-difference time-domain (FDTD) method. The results show that dual-PIT can be effectively tuned by Fermi levels, carrier mobilities, and polarization angles. Moreover, the group index can be as high as ∼2553. These results may pave the way for the design of slow-light devices.

Abstract-Theoretical Analysis of Plasmon-Induced Transparency in Ring-resonators Coupled Channel Drop Filter Systems

• Shiping Zhan, 
• Hongjian Li, 
• Guangtao Cao, 
• Zhihui He, 
• Boxun Li, 
• Hui Xu

http://link.springer.com/article/10.1007/s11468-014-9760-x

The plasmon-induced transparency (PIT) in ring-resonators coupled channel drop filter (CDF) systems is investigated theoretically and numerically in this paper. A coupled mode theory-based transfer matrix method (CMT-TMM) is introduced owning to the symmetric and evanescent coupling, which is confirmed by the finite-difference time-domain (FDTD) simulation results. The drop waveguide provides the necessary optical feedback for the interference effect in realizing the PIT, and a new way for adjusting PIT effect in a fixed structure is also given. Finally, the phase and the group dispersion in the transparency window are discussed for investigating the slow light effect in our systems, and a group index of ~22 is obtained. The proposed plasmonic systems possess both the slow light and the dropping properties and may have potential and flexible applications in fundamental research of integrated plasmonic devices.