Abstract-Tunable defect modes of one-dimensional photonic crystals containing a Dirac semimetal-based metamaterial defect layer

Qin Wang, Xinliang Wang, Liwei Zhang, Yongqiang Wang, Wentao Qiao, Xu Han, Xiaolin Cai, and Weiyang Yu

https://www.osapublishing.org/ao/abstract.cfm?uri=ao-58-1-94&origin=search

The transmission properties of one-dimensional photonic crystals (PCs) containing a metamaterial (MM) defect layer are investigated using the transfer matrix method. The MM is composed of alternating layers of a dielectric material and a Dirac semimetal (DS) material. Numerical results show that the defective PCs possess a tunable defect mode, which is significantly dependent on the Fermi level of the DS as well as the structural parameters of the MM defect layer. The defect mode properties under different incident angles for TE and TM polarizations are also studied. Such defective structures have potential applications in tunable filters and sensors in terahertz regions.

© 2018 Optical Society of America

Abstract-A magnetically tunable non-Bragg defect mode in a corrugated waveguide filled with liquid crystals

Lu Zhang, Ya-Xian Fan,  Huan Liua, Xu Han, Wen-Qiang Luc, Zhi-Yong Tao,

https://www.sciencedirect.com/science/article/pii/S0375960118301737

A magnetically tunable, non-Bragg defect mode (NBDM) was created in the terahertz frequency range by inserting a defect in the middle of a periodically corrugated waveguide filled with liquid crystals (LCs). In the periodic waveguide, non-Bragg gaps beyond the Bragg ones, which appear in the transmission spectra, are created by different transverse mode resonances. The transmission spectra of the waveguide containing a defect showed that a defect mode was present inside the non-Bragg gap. The NBDM has quite different features compared to the Bragg defect mode, which includes more complex, high-order guided wave modes. In our study, we filled the corrugated waveguide with LCs to realize the tunability of the NBDM. The simulated results showed that the NBDM in a corrugated waveguide filled with LCs can be used in filters, sensors, switches, and other terahertz integrated devices.

Abstract-Plasmon-induced transparency effect in a single circular split-ring core ring resonator side-coupled to a metal-isolator-metal waveguide

Youjiang Zhu¹, Tao Wang^1,a), Xu Han¹ and Boyun Wang¹
http://scitation.aip.org/content/aip/journal/jap/117/13/10.1063/1.4916751?TRACK=RSS
1 Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
a) Electronic mail: wangtao@hust.edu.cn
J. Appl. Phys. 117, 133108 (2015); http://dx.doi.org/10.1063/1.4916751

We theoretically and numerically investigated the plasmon-induced transparency (PIT) effect in a single circular split-ring core ring resonator (CSRCRR) side coupled to a metal–isolator–metal waveguide, in which we can realize a single PIT effect window. The transmission linetheory and the coupled mode theory are used. The results (transmission peak varies from 10% to 75%) show that the PIT window results from the destructive interference between the resonance modes in the CSRCRR. Then, the limit of wavelength detuning of the two modes in CSRCRR is studied. This work provides a new structure to realize the PIT effect and shows a new way to judge whether the phenomenon is the real PIT effect or not.