Voltage-controlled liquid-crystal terahertz phase shifter and quarter-wave plate.
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.
Hsieh
Cho-Fan
CF
Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan 30010.
Pan
Ru-Pin
RP
Tang
Tsung-Ta
TT
Chen
Hung-Lung
HL
Pan
Ci-Ling
CL