Open AccessTunable terahertz wave-plate based on dual-frequency liquid crystal controlled by alternating electric field
Author(s) -
JieHui Yu,
Sai Chen,
Fei Fan,
Jierong Cheng,
ShiTong Xu,
Xianghui Wang,
Shengjiang Chang
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.000663
Subject(s) - terahertz radiation , electric field , optics , materials science , birefringence , waveplate , polarization (electrochemistry) , refractive index , optoelectronics , physics , chemistry , laser , quantum mechanics
In this work, the optically anisotropic property of dual-frequency liquid crystals (DFLC) in terahertz (THz) regime has been experimentally investigated, which indicates that the refractive index and birefringence of DFLC can be continuously modulated by both the alternating frequency and intensity of the alternating electric field. This tunability originates from the rotation of DFLC molecules induced by alternating electric fields. The results show that by modulating the alternating frequency from 1 kHz to 100 kHz under 30 kV/m electric field, the 600 μm thickness DFLC cell can play as a tunable quarter-wave plate above 0.68 THz, or a half-wave plate above 1.33 THz. Besides, it can be viewed as a tunable THz phase shifter from 0 to π. Therefore, due to its novel tuning mechanism, DFLC will be of great significance in dynamic manipulating on THz phase and polarization.