Browsing by Author "Wu, Chun-Hung"

Now showing 1 - 4 of 4

A reflective polarizer-free electro-optical switch using dye-doped polymer-stabilized blue phase liquid crystals
(2011-01-31)
Lin, Yi-Hsin
;
Chen, Hung-Shan
;
Chiang, Tsung-Han
;
Wu, Chun-Hung
;
Hsu, Hsu-Kuan
We demonstrate a reflective polarizer-free electro-optical switch using dye-doped polymer-stabilized blue phase liquid crystals (DDPSBP-LC). At the voltage-off state, the dye molecules and liquid crystals form the structure of the double twist cylinders. As a result, the DDPSBP-LC is in dark state due to the combination of Bragg reflection and light absorption. At the voltage-on state, the blue phase structure is unwound locally. The DDPSBP-LC is then in bright state because of the small light absorption only. The applications of such a switch are shutter glass of 3D displays, and electronic papers. (C) 2011 Optical Society of America
Hysteresis of Polymer Stabilized Blue Phase Liquid Crystals
(2012)
Chen, Hung-Shan
;
Wu, Chun-Hung
;
Chen, Michael
;
Lin, Yi-Hsin
;
光電工程學系
We demonstrate a hysteresis-free polymer-stabilized blue phase liquid crystals (PSBP-LCs) as well as hysteresis-free dye-doped polymer stabilized blue phase liquid crystals (DDPSBP-LCs) by means of enlarging the domain size and improving the uniformity of the crystal orientations of PSBP-LC and DDPSBP-LC. The mechanism based on the crystal growth is proposed. The hysteresis-free PSBP-LC (or DDPSBP-LC) is important in PSBP-LC-based photonic devices, such as displays, electro-optical switches, and electrically tunable focusing LC lenses.
Hysteresis-free polymer-stabilized blue phase liquid crystals using thermal recycles
(1970-01-01)
Chen, Hung-Shan
;
Lin, Yi-Hsin
;
Wu, Chun-Hung
;
Chen, Michael
;
Hsu, Hsu-Kuan
"We demonstrate a hysteresis-free polymer-stabilized blue phase liquid crystals (PSBP-LCs) using thermal recycles by means of enlarging the domain size of PSBP-LC and improving the uniformity of the crystal orientations of PSBP-LC. The crystal growth of PSBP-LCs bases on a competition between the heterogeneous nucleation and the homogeneous nucleation is also demonstrated and discussed. This study opens a new window for understanding the hysteresis of the PSBP-LC and assisting in designing many PSBP-LC-based photonic devices, such as displays, electro-optical switches, and electrically tunable focusing LC lenses. (C)2012 Optical Society of America"
Measuring electric-field-induced birefringence in polymer stabilized blue-phase liquid crystals based on phase shift measurements
(2011-05-15)
Lin, Yi-Hsin
;
Chen, Hung-Shan
;
Wu, Chun-Hung
;
Hsu, Hsu-Kuan
;
光電工程學系
A simple optical method to measure the electric-field-induced birefringence and Kerr constant of polymer-stabilized blue-phase liquid crystals (PSBP-LC) is demonstrated. By measuring the phase shift of PSBP-LC and the averaged refractive index of PSBP-LC at the voltage-off state, the ordinary refractive index and extraordinary refractive index of PSBP-LC as function of applied voltage can be obtained experimentally. As a result, the electric-field-induced birefringence and Kerr constant can be determined as well. The method we proposed can help in designing PSBP-LC-based photonic devices. (C) 2011 American Institute of Physics. [doi:10.1063/1.3583572]