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Updated: Aug 9, 2026

An Electrochemical Cholesteric Liquid Crystalline Device for Quick and Low-Voltage Color Modulation
Published on: February 27, 2019
Voltage-controlled liquid-crystal terahertz phase shifter and quarter-wave plate
Cho-Fan Hsieh1, Ru-Pin Pan, Tsung-Ta Tang
1Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan 30010.
Abstract:
Phase shift exceeding tau/2 at 1 THz is demonstrated by using electrically controlled birefringence in a homeotropically aligned nematic liquid crystal (E7) cell, 570 microm in thickness. The driving voltage required for a phase shift of 90 degrees is 125 V (rms). We demonstrate that the phase shifter works as an electrically switchable quarter-wave plate at 1 THz. The device can also be used as an electrically tuned phase compensator around the quarter-wave point near 1 THz.
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