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.