Abstract-Multi-band terahertz metamaterial absorber for sensing application

Yuan Yao, Shaopeng Li, Lei Zhu, Fengmin Wu, Xunjun He,  Jiuxing JiangYu

https://www.tandfonline.com/doi/abs/10.1080/10584587.2018.1457352?journalCode=ginf20

In this paper, we proposed a multi-band metamaterial absorber for sensing thin film, which consists of tri-layer structure: patterned multi-split electric ring resonators layer, dielectric spacer layer, and continuous metal ground layer. The calculated results demonstrated that the absorber can exhibit three distinctive absorption peaks with narrow bandwidth. As the surface of the absorber was coated with the analyte layer, moreover, the locations of three absorption peaks appear obvious redshift, and the corresponding maximal sensitivities are 0.119 THz/RIU, 0.248 THz/RIU, and 0.662 THz/RIU, respectively. Therefore, the proposed absorber has significant potential applications in detecting and sensing.

Abstract-Dynamically controlled electromagnetically induced transparency in terahertz graphene metamaterial for modulation and slow light applications

Xunjun He, Yuan Yao, Xingyu Yang, Guangjun Lu, Wenlong Yang, Yuqiang Yang, Fengmin Wu, Zhigang Yu, Jiuxing Jiang,

http://www.sciencedirect.com/science/article/pii/S0030401817307745

By patterning two graphene resonators on a SiO₂/Si substrate, a dynamically controlled electromagnetically induced transparency (EIT) in the terahertz graphene metamaterial was numerically studied through tuning the structural parameter and Fermi energy of graphene. The calculated surface current distributions demonstrate that the distinct EIT window in the graphene metamaterial results from the near-field coupling of two graphene resonators. Moreover, the EIT window can be actively controlled by tuning Fermi energy combined states of two resonators. When the Fermi energy combined state of two resonators changes from (0.21 and 0.16 eV) to (0.4 and 0.11 eV), the amplitude modulation depth of the EIT peak is 97.8% at 0.45 THz, and the corresponding enhanced factor of group delay with 6 times is obtained. This study offers an alternative tuning method to existing optical, thermal, and relative distance tuning, delivering a promising potential for designing active and miniaturized THz devices.

Abstract-One-dimensional multiband terahertz graphene photonic crystal filters

Yizhe Li, Limei Qi, Junsheng Yu, Zhijiao Chen, Yuan Yao, and Xiaoming Liu

https://www.osapublishing.org/ome/abstract.cfm?uri=ome-7-4-1228&origin=search

Properties of one-dimensional graphene photonic crystals with dual-layer defects are studied. Results show that two defect modes appear within the gaps, and the defect modes shift to the lower frequencies with the chemical potential increasing, the physical mechanism are also given based on the relative dielectric constant of the graphene. It is also found that the frequency, magnitude, and numbers of the defect modes can vary with the symmetrical changes of the dual-defect layers. For oblique incidence, the defect modes of the TE polarization follow a similar trend with the TM polarization, and all the defect modes shift to the higher frequencies and disappear while new defect modes appear at the larger incident angles. These properties of graphene photonic crystals with dual-layer defects have potential applications in tunable terahertz narrow multiband filters.

© 2017 Optical Society of America