Electrically Tunable Propagation Properties of the Liquid Crystal-Filled Terahertz Fiber

Abstract

A bandgap-guiding microstructured fiber for terahertz (THz) radiation was designed by infiltrating the cladding air holes with nematic liquid crystal. Structural parameter dependence of the photonic bandgaps, polarization-dependent bandgap splitting, and electrically tunable propagation properties of the designed fiber were investigated theoretically by using the finite-element method. An external electric field applied across the designed fiber can broaden the effective transmission bandwidth and achieve single-mode single-polarization guidance. Flattened near-zero group-velocity dispersion of 0 ± 1 ps/THz/cm was obtained for the y-polarized fundamental mode within a broad frequency range. Our results provide theoretical references for applications of liquid crystal-filled microstructured fiber for dynamic polarization control and tunable fiber devices in THz frequency.

Electro-optical effect of the nCOOCB liquid crystal molecules under the terahertz frequency range: A theoretical approach

“…Wang et al have reported that under the applied field, the director angle is reoriented due to an inherent behaviour of the nematic LCs. 28 The nCOOCB LCs do not have any homogeneous alignment under the applied high electric field due to its internal geometry with intermolecular forces. The even-odd effect in the director angle is also related with the shape and size of LCs in the series.…”