scholarly journals Multi-Wavelength Filters of Templated Blue Phase Liquid Crystal

Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 451 ◽  
Author(s):  
Shenghao Zha ◽  
Hongzhou Zhang ◽  
Changli Sun ◽  
Yifan Feng ◽  
Jiangang Lu
Keyword(s):  
Liquid Crystal ◽  
Incident Angle ◽  
Incident Light ◽  
Cholesteric Liquid Crystal ◽  
Temperature Shift ◽  
Central Wavelength ◽  
Multi Wavelength ◽  
Phase Liquid ◽  
Blue Phase ◽  
Wavelength Filters

The multi-wavelength filters in the visible light band using the blue phase liquid crystal (BPLC) template was investigated. A multi-layer templated BPLC (T-BPLC) filter without intermediate dielectric layers was fabricated, which may reflect multi-wavelength in one filter. Compared with the cholesteric liquid crystal (CLC) filter, the T-BPLC filter may get a much narrower reflection bandwidth (<15 nm), show better angular stability of incident light, and have a more stable wavelength and bandwidth with a temperature shift. Furthermore, the central wavelength and bandwidth can be easily controlled by the fabrication process and the optimization of the material concentration. When the incident angle varies, the shift of the center wavelength of the T-BPLC filter is much smaller than that of the CLC filter. The multi-wavelength filter shows a potential application in color filters and high-density wavelength division multiplexed networks.

scholarly journals Effect of Sectional Polymerization Process on Tunable Twist Structure Liquid Crystal Filters

Crystals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 268
Author(s):  
Changli Sun ◽  
Jiangang Lu
Keyword(s):  
Liquid Crystal ◽  
Cholesteric Liquid Crystal ◽  
Wide Band ◽  
Polymerization Process ◽  
Central Wavelength ◽  
Hyper Spectral ◽  
Phase Liquid ◽  
Blue Phase ◽  
Polymer Stabilized ◽  
Color Filters

The effect of sectional polymerization process on tunable filters with cholesteric liquid crystal (CLC) and blue phase liquid crystal (BPLC) is demonstrated. The bandwidths of the polymer-stabilized cholesteric liquid crystal (PSCLC) and polymer-stabilized blue phase liquid crystal (PSBPLC) filters can be broadened by the holding treatment without distortion. The reflection bandwidth of the CLC filter can be broadened from 120 nm to 220 nm, and that of the BPLC filter can be broadened from 45 nm to 140 nm. Meanwhile, the intensity of reflection can be retained very well. The central wavelength of polymer-stabilized CLC filter can be thermally tuned from 1614 nm to 1460 nm with a stable wide bandwidth. The tunable C-band CLC filter and BPLC filter show great potential application in multi- and hyper-spectral systems and wide-band color filters.

Multi-wavelength filters of templated blue phase liquid crystal

2019 ◽  
Vol 34 (9) ◽  
pp. 835-840
Author(s):  
查升毫 ZHA Sheng-hao ◽  
孙长俐 SUN Chang-li ◽  
冯一凡 FENG Yi-fan ◽  
陆建钢 LU Jian-gang
Keyword(s):  
Liquid Crystal ◽  
Multi Wavelength ◽  
Phase Liquid ◽  
Blue Phase ◽  
Wavelength Filters

scholarly journals Electrically-Tunable Blue Phase Liquid Crystal Microlens Array Based on a Photoconductive Film

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 65 ◽  
Author(s):  
Bing-Yau Huang ◽  
Shuan-Yu Huang ◽  
Chia-Hsien Chuang ◽  
Chie-Tong Kuo
Keyword(s):  
Refractive Index ◽  
Liquid Crystal ◽  
Electric Field ◽  
Uv Light ◽  
Focal Length ◽  
Incident Light ◽  
Microlens Array ◽  
Gradient Distribution ◽  
Phase Liquid ◽  
Blue Phase

This paper proposes an effective approach to fabricate a blue phase liquid crystal (BPLC) microlens array based on a photoconductive film. Owing to the characteristics of photo-induced conducting polymer polyvinylcarbazole (PVK), in which conductivity depends on the irradiation of UV light, a progressive mask resulting in the variation of conductivity is adopted to produce the gradient distribution of the electric field. The reorientations of liquid crystals according to the gradient distribution of the electric field induce the variation of the refractive index. Thus, the incident light experiences the gradient distribution of the refractive index and results in the focusing phenomenon. The study investigates the dependence of lens performance on UV exposure time, the focal length of the lens, and focusing intensities with various incident polarizations. The BPLC microlens array exhibits advantages such as electrically tunability, polarization independence, and fast response time.

Tunable Optical Filter with Variable Bandwidth Based on Cholesteric Liquid Crystal

2011 ◽  
Vol 181-182 ◽  
pp. 273-276
Author(s):  
Shi Chao Zhang ◽  
Yu Hua Huang
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Incident Light ◽  
Cholesteric Liquid Crystal ◽  
Optical Filter ◽  
Tunable Filter ◽  
Cholesteric Liquid Crystals ◽  
Central Wavelength ◽  
Variable Bandwidth ◽  
Tunable Optical Filter

An optical tunable filter with variable bandwidth has been demonstrated using two cholesteric liquid crystals. The incident light was first reflected by the first cholesteric liquid crystal and then by the second one. By rotating the two cholesteric liquid crystals simultaneously, the central wavelength can be tuned. By fixing one of the cholesteric liquid crystals and rotating the other one, the bandwidth of the tunable filter can be varied. The central wavelength of the tunable optical filter can be tuned from 513.4 nm to 576.8 nm and the bandwidth is varied from 10 nm to 80 nm. This property will allow it to be widely used in many fields, including optical communications and multispectral and hyperspectral imaging systems.

Electrically Switched Liquid Crystal Color and Device Applications

2010 ◽  
Vol 428-429 ◽  
pp. 24-28
Author(s):  
Shin Ying Lu ◽  
Liang Chy Chien
Keyword(s):  
Liquid Crystal ◽  
Incident Light ◽  
Cholesteric Liquid Crystal ◽  
Blue Shift ◽  
Additive Formulation ◽  
Device Applications ◽  
Blue Phase ◽  
Different Color ◽  
Polymer Stabilized ◽  
Color Filters

We demonstrate a polymer-stabilized cholesteric liquid crystal (PSChLC) where the reflected color can be electrically-switched to reflect a different color at a shorter wavelength (blue-shift). A polymerizable additive formulation is used to ensure a wider range of color tuning and anisotropic reflection where on side reflects and the other side transmits the incident light in response to applied voltage. A second electrically switched color based on polymer-stabilized blue phase (PSBP) liquid crystal is also demonstrated. Applying an electric field across the cell results in a red-shift in Bragg reflected wavelength due to the electrostriction effect. These switchable color devices of are color filters and polarizers free which are suitable for electronic papers.

scholarly journals A polarization-independent blue phase liquid crystal on silicon with low operation voltage

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Changli Sun ◽  
Jiangang Lu
Keyword(s):  
Liquid Crystal ◽  
Phase Modulation ◽  
Light Propagation ◽  
Incident Light ◽  
Optical Path ◽  
Imaging Systems ◽  
Phase Liquid ◽  
Blue Phase ◽  
Liquid Crystal On Silicon ◽  
Polarization Independent

AbstractA polarization-independent blue phase liquid crystal on silicon (BPLCoS) device with low operation voltage for 2π phase depth is demonstrated. With optimized reflection structure and two reflection films, the incident light may experience multifold optical path and 2π phase depth can be obtained. For the polarization-independence, an inclined electric field made by periodical gradient voltage is applied on the blue phase liquid crystal (BPLC) to match the light propagation direction. With the structure, the operation voltage can be lowered to 5.5 V in simulation and 5.9 V in experiment for 2π phase modulation at 1550 nm. The proposed device shows great potential for communication and imaging systems.

scholarly journals Low voltage and high contrast blue phase liquid crystal with red-shifted Bragg reflection

2013 ◽  
Vol 102 (1) ◽  
pp. 011113 ◽  
Author(s):  
Jin Yan ◽  
Zhenyue Luo ◽  
Shin-Tson Wu ◽  
Jyh-Wen Shiu ◽  
Yu-Cheng Lai ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Low Voltage ◽  
Bragg Reflection ◽  
High Contrast ◽  
Phase Liquid ◽  
Blue Phase

Hydrogen-bonded bent-core blue phase liquid crystal complexes containing various molar ratios of proton acceptors and donors

RSC Advances ◽  
2016 ◽  
Vol 6 (38) ◽  
pp. 32319-32327 ◽  
Author(s):  
Chun-Chieh Han ◽  
Yu-Chaing Chou ◽  
San-Yuan Chen ◽  
Hong-Cheu Lin
Keyword(s):  
Liquid Crystal ◽  
Chain Length ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Chiral Center ◽  
Molar Ratio ◽  
Core Complex ◽  
Molar Ratios ◽  
Phase Liquid ◽  
Blue Phase

The molar ratio, alkyl chain length, lateral fluoro-substitution and the chiral center of H-bonded bent-core supramolecules would affect the BP ranges of BPLC complexes. H-bonded bent-core complex PIIIC9/AIIF* (3/7 mol mol−1) displayed the widest BPI range of ΔTBPI = 12 °C.

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