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Nakajima K, Ozaki M. Anisotropic crystal growth in blue phase I transitioned from a uniformly oriented cholesteric phase. SOFT MATTER 2024; 20:4072-4078. [PMID: 38712495 DOI: 10.1039/d4sm00289j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Phase transitions in blue phase liquid crystals (BPLCs) have attracted significant attention from the technical perspective of BP orientation control and the theoretical perspective of analogs with crystalline solids. The phase transition phenomena in BPs significantly depend on the phase state before the transition. In this study, we focused on the cholesteric (Ch)-BPI phase transition and found that BPI crystals exhibited a square shape upon the phase transition from the uniformly oriented Ch phase to the BPI phase. This square crystal shape was common across three BPLC materials with different elastic constants, and the shape reflected the crystal axis. The in-plane crystal orientation correlates with the easy axis on the substrate surface, suggesting that the [011] axis tends to coincide with the easy axis. However, the easy axis has little effect on the crystal growth rate. Furthermore, scratches on the substrate surface promoted nucleation. Based on this behavior, it was demonstrated that the nucleation position and density could be controlled by intentionally disturbing the Ch orientation by locally changing the easy axis using photoalignment. This study focused on the anisotropic crystal growth of BPI, providing interesting insights into LC phase transitions and soft matter crystal growth. In addition, it offers techniques for the fabrication of large BPI crystals, contributing to the enhanced electrical and optical performances of BPLC devices.
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Affiliation(s)
- Kazuma Nakajima
- Division of Electrical, Electronic and Infocommunications Engineering, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
| | - Masanori Ozaki
- Division of Electrical, Electronic and Infocommunications Engineering, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
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2
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Nakajima K, Mitsuhashi S, Cho S, Ozaki M. Slanted Structure of Blue Phase II Self-Aligned on One-Dimensional Patterned Surfaces. ACS APPLIED MATERIALS & INTERFACES 2023; 15:40054-40061. [PMID: 37552214 DOI: 10.1021/acsami.3c07293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
Orientation analysis of liquid crystal (LC) devices is important for understanding and controlling light propagation behavior in these devices. Blue phases (BPs)─unique LC phases that self-organize into three-dimensional helical structures─are candidate materials for LC-based reflective diffractors. We realized BPII deflectors with large diffraction angles using one-dimensional surface alignment patterns. We analyzed the BPII lattice arrangement in the deflector based on Bragg reflections and demonstrated that the lattice structure was slanted with respect to the substrate, which was confirmed using transmission electron microscopy. In addition, we calculated the similarity between the alignment pattern on the substrate surface and the director arrangement of BPII near the interface, confirming that the structure observed experimentally matched the most probable calculated structure. Thus, this study contributes to the optical design of BPII deflectors and provides information on the orientation mechanism in high-order self-organizing soft matter structures.
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Affiliation(s)
- Kazuma Nakajima
- Division of Electrical, Electronic and Infocommunications Engineering, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - Shogo Mitsuhashi
- Division of Electrical, Electronic and Infocommunications Engineering, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - SeongYong Cho
- Division of Electrical, Electronic and Infocommunications Engineering, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - Masanori Ozaki
- Division of Electrical, Electronic and Infocommunications Engineering, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
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3
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Negro G, Carenza LN, Gonnella G, Marenduzzo D, Orlandini E. Topological phases and curvature-driven pattern formation in cholesteric shells. SOFT MATTER 2023; 19:1987-2000. [PMID: 36847796 DOI: 10.1039/d2sm01347a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
We study the phase behaviour of cholesteric liquid crystal shells with different geometries. We compare the cases of tangential anchoring and no anchoring at the surface, focussing on the former case, which leads to a competition between the intrinsic tendency of the cholesteric to twist and the anchoring free energy which suppresses it. We then characterise the topological phases arising close to the isotropic-cholesteric transition. These typically consist of quasi-crystalline or amorphous tessellations of the surface by half-skyrmions, which are stable at lower and larger shell sizes, respectively. For ellipsoidal shells, defects in the tessellation couple to a local curvature, and according to the shell size, they either migrate to the poles or distribute uniformly on the surface. For toroidal shells, the variations in the local curvature of the surface stabilise heterogeneous phases where cholesteric or isotropic patterns coexist with hexagonal lattices of half-skyrmions.
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Affiliation(s)
- G Negro
- Dipartimento di Fisica, Università degli Studi di Bari and INFN, Sezione di Bari, via Amendola 173, Bari, I-70126, Italy
| | - L N Carenza
- Instituut-Lorentz, Universiteit Leiden, P.O. Box 9506, 2300 RA Leiden, The Netherlands.
| | - G Gonnella
- Dipartimento di Fisica, Università degli Studi di Bari and INFN, Sezione di Bari, via Amendola 173, Bari, I-70126, Italy
| | - D Marenduzzo
- SUPA, School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, UK
| | - E Orlandini
- Dipartimento di Fisica e Astronomia, Università di Padova, 35131 Padova, Italy
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4
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Bo S, Chen B, Zhu D, Feng S, Chen Z. Low-voltage and fast-response polymer-stabilized blue-phase liquid crystals achieved using a new organosilicone monomer. SOFT MATTER 2022; 18:8188-8193. [PMID: 36268983 DOI: 10.1039/d2sm01075e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
In this paper, two types of polymer-stabilized blue-phase liquid crystals (PS-BPLCs) with different monomers were designed and prepared. The morphology, temperature range and electro-optical properties of the blue phases were studied and discussed. The temperature range of both types of PS-BPLC is greater than 110 °C, and both samples can be stabilized well at room temperature. The organosilicone monomer 3-methacryloxypropyltrimethoxysilane (KH570), which contains double bonds, was introduced to a blue-phase system for the first time. Regarding the electro-optical performance, the on-state voltage of the PS-BPLCs with the KH570 monomer is reduced to 30 V compared with traditional C12A monomer systems in which the on-state voltage is 75 V at 458 nm. Meanwhile, a fast response and suppressed hysteresis are obtained. These results are helpful to the application of displays and photonic devices.
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Affiliation(s)
- Shuhui Bo
- Optoelectronics Research Centre, School of Science, Minzu University of China, Beijing, 100081, P. R. China.
- Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
| | - Baohui Chen
- Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
| | - Dongping Zhu
- Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
| | - Shuai Feng
- Optoelectronics Research Centre, School of Science, Minzu University of China, Beijing, 100081, P. R. China.
| | - Zhuo Chen
- Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
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Sun C, Lu J. A polarization-independent blue phase liquid crystal on silicon with low operation voltage. Sci Rep 2019; 9:16900. [PMID: 31729452 PMCID: PMC6858364 DOI: 10.1038/s41598-019-53344-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 10/31/2019] [Indexed: 11/13/2022] Open
Abstract
A 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.
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Wang X, Fells JAJ, Yip WC, Ali T, Lin JD, Welch C, Mehl GH, Booth MJ, Wilkinson TD, Morris SM, Elston SJ. Fast and low loss flexoelectro-optic liquid crystal phase modulator with a chiral nematic reflector. Sci Rep 2019; 9:7016. [PMID: 31064999 PMCID: PMC6504954 DOI: 10.1038/s41598-019-42831-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 04/05/2019] [Indexed: 11/09/2022] Open
Abstract
In this paper, we demonstrate a flexoelectro-optic liquid crystal phase-only device that uses a chiral nematic reflector to achieve full 2π phase modulation. This configuration is found to be very tolerant to imperfections in the chiral nematic reflector provided that the flexoelectro-optic LC layer fulfils the half-wave condition. Encouragingly, the modulation in the phase, which operates at kHz frame rates, is also accompanied by low amplitude modulation. The configuration demonstrated herein is particularly promising for the development of next-generation liquid crystal on silicon spatial light modulators.
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Affiliation(s)
- Xiuze Wang
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
| | - Julian A J Fells
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
| | - Wing C Yip
- Department of Engineering, University of Cambridge, Cambridge, CB3 0FA, UK
| | - Taimoor Ali
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
| | - Jia-de Lin
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
| | - Chris Welch
- Department of Chemistry, University of Hull, Hull, HU6 7RX, UK
| | - Georg H Mehl
- Department of Chemistry, University of Hull, Hull, HU6 7RX, UK
| | - Martin J Booth
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK
| | | | - Stephen M Morris
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK.
| | - Steve J Elston
- Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK.
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Pursuing High Quality Phase-Only Liquid Crystal on Silicon (LCoS) Devices. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8112323] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Fine pixel size and high-resolution liquid crystal on silicon (LCoS) backplanes have been developed by various companies and research groups since 1973. The development of LCoS is not only beneficial for full high definition displays but also to spatial light modulation. The high-quality and well-calibrated panels can project computer generated hologram (CGH) designs faithfully for phase-only holography, which can be widely utilized in 2D/3D holographic video projectors and components for optical telecommunications. As a result, we start by summarizing the current status of high-resolution panels, followed by addressing issues related to the driving frequency (i.e., liquid crystal response time and hardware interface). LCoS panel qualities were evaluated based on the following four characteristics: phase linearity control, phase precision, phase stability, and phase accuracy.
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Lin P, Yan Q, Wei Z, Chen Y, Chen F, Huang Z, Li X, Wang H, Wang X, Cheng Z. All-inorganic perovskite quantum dots stabilized blue phase liquid crystals. OPTICS EXPRESS 2018; 26:18310-18319. [PMID: 30114012 DOI: 10.1364/oe.26.018310] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/27/2018] [Indexed: 06/08/2023]
Abstract
All-inorganic perovskite quantum dots (PQDs) have been effectively incorporated in the three-dimensional ordered structure of blue phase liquid crystals (BPLCs) to stabilize the BPLCs. Uniform dispersion, reduced phase transition temperature, widened BP temperature range, dynamic and fast electro-optical response and static optical display of selective reflection mode and photoluminescence mode have been confirmed with a given concentration of PQDs. Such a novel strategy of assembling all-inorganic PQDs in BPLCs shows favorable prospects for wide-range and near room temperature BPLCs, responsive BPLCs, multifunctional display materials and tunable bandgap lasers.
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Two-photon polymerization enabled multi-layer liquid crystal phase modulator. Sci Rep 2017; 7:16260. [PMID: 29176729 PMCID: PMC5701147 DOI: 10.1038/s41598-017-16596-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 11/15/2017] [Indexed: 11/08/2022] Open
Abstract
The performance of liquid crystal (LC) spatial light modulators depends critically on the amount of cumulative phase change. However, for regular phase modulators, a large phase change comes with a slow time response penalty. A multi-layer liquid crystal (LC) spatial light modulator offers a large phase change while keeping fast response time due to the decoupling between phase change and time response through engineered sub-micron scaffold. Here, we demonstrate specially designed 2- and 3-layer LC cells which can achieve 4 times and 7 times faster response time than that of conventional single-layer LC phase modulator of equivalent thickness, respectively. A versatile two-photon laser lithography is employed for LC cell scaffolding to accurately verify theoretical predictions with experimental measurements.
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Wang Y, Wang F, Zhang Y, Huang X, Hu D, Zheng W, Zhu R, Deng X. Polarization smoothing for single beam by a nematic liquid crystal scrambler. APPLIED OPTICS 2017; 56:8087-8091. [PMID: 29047670 DOI: 10.1364/ao.56.008087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 09/11/2017] [Indexed: 06/07/2023]
Abstract
Polarization smoothing (PS) is a key approach to suppress laser plasma instabilities (LPI) in inertial confinement fusion (ICF) experiments. Here, we propose a liquid crystal (LC) PS element to realize single beam smoothing and demonstrate its smoothing effect, in principle, with a 2×2 LC polarization checkerboard, which reduces the laser intensity variation in the focal spot to 78.4%. LC PS elements, which have potential applications in high-power ICF laser drivers, have many advantages because they are easy to fabricate, cost effective, flexible, and large.
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Meng X, Gorbunov AV, Christian Roelofs WS, Meskers SCJ, Janssen RAJ, Kemerink M, Sijbesma RP. Ferroelectric switching and electrochemistry of pyrrole substituted trialkylbenzene-1,3,5-tricarboxamides. ACTA ACUST UNITED AC 2017; 55:673-683. [PMID: 28344384 PMCID: PMC5347932 DOI: 10.1002/polb.24318] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 01/26/2017] [Indexed: 01/11/2023]
Abstract
We explore a new approach to organic ferroelectric diodes using a benzene‐tricarboxamide (BTA) core connected with C10 alkyl chains to pyrrole groups, which can be polymerized to provide a semiconducting ferroelectric material. The compound possesses a columnar hexagonal liquid crystalline (LC) phase and exhibits ferroelectric switching. At low switching frequencies, an additional process occurs, which leads to a high hysteretic charge density of up to ∼1000 mC/m2. Based on its slow rate, the formation of gas bubbles, and the emergence of characteristic polypyrrole absorption bands in the UV–Vis–NIR, the additional process is identified as the oxidative polymerization of pyrrole groups, enabled by the presence of amide groups. Polymerization of the pyrrole groups, which is essential to obtain semiconductivity, is limited to thin layers at the electrodes, amounting to ∼17 nm after cycling for 21 h. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 673–683
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Affiliation(s)
- Xiao Meng
- Laboratory of Macromolecular and Organic Chemistry Eindhoven University of Technology PO Box 513 Eindhoven MB 5600 The Netherlands
| | - Andrey V Gorbunov
- Department of Applied Physics Eindhoven University of Technology PO Box 513 Eindhoven MB 5600 The Netherlands
| | - W S Christian Roelofs
- Department of Applied Physics Eindhoven University of Technology PO Box 513 Eindhoven MB 5600 The Netherlands
| | - Stefan C J Meskers
- Laboratory of Macromolecular and Organic Chemistry Eindhoven University of Technology PO Box 513 Eindhoven MB 5600 The Netherlands
| | - René A J Janssen
- Laboratory of Macromolecular and Organic Chemistry Eindhoven University of Technology PO Box 513 Eindhoven MB 5600 The Netherlands; Department of Applied Physics Eindhoven University of Technology PO Box 513 Eindhoven MB 5600 The Netherlands
| | - Martijn Kemerink
- Department of Applied Physics Eindhoven University of Technology PO Box 513 Eindhoven MB 5600 The Netherlands; Complex Materials and Devices, Department of Physics, Chemistry and Biology (IFM) Linköping University Linköping SE 58183 Sweden
| | - Rint P Sijbesma
- Laboratory of Macromolecular and Organic Chemistry Eindhoven University of Technology PO Box 513 Eindhoven MB 5600 The Netherlands
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Lin JD, Wang TY, Mo TS, Huang SY, Lee CR. Wide-Band Spatially Tunable Photonic Bandgap in Visible Spectral Range and Laser based on a Polymer Stabilized Blue Phase. Sci Rep 2016; 6:30407. [PMID: 27456475 PMCID: PMC4960656 DOI: 10.1038/srep30407] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 07/05/2016] [Indexed: 11/24/2022] Open
Abstract
This work successfully develops a largely-gradient-pitched polymer-stabilized blue phase (PSBP) photonic bandgap (PBG) device with a wide-band spatial tunability in nearly entire visible region within a wide blue phase (BP) temperature range including room temperature. The device is fabricated based on the reverse diffusion of two injected BP-monomer mixtures with a low and a high chiral concentrations and afterwards through UV-curing. This gradient-pitched PSBP can show a rainbow-like reflection appearance in which the peak wavelength of the PBG can be spatially tuned from the blue to the red regions at room temperature. The total tuning spectral range for the cell is as broad as 165 nm and covers almost the entire visible region. Based on the gradient-pitched PSBP, a spatially tunable laser is also demonstrated in this work. The temperature sensitivity of the lasing wavelength for the laser is negatively linear and approximately -0.26 nm/°C. The two devices have a great potential for use in applications of photonic devices and displays because of their multiple advantages, such as wide-band tunability, wide operated temperature range, high stability and reliability, no issue of hysteresis, no need of external controlling sources, and not slow tuning speed (mechanically).
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Affiliation(s)
- Jia-De Lin
- National Cheng Kung University, Department of Photonics, Tainan, 701, Taiwan
| | - Tsai-Yen Wang
- National Cheng Kung University, Department of Photonics, Tainan, 701, Taiwan
| | - Ting-Shan Mo
- Kun Shan University of Technology, Department of Electro-Optical Engineering, Tainan, 710, Taiwan
| | - Shuan-Yu Huang
- Chung Shan Medical University, Department of Optometry, Taichung, 402, Taiwan
- Chung Shan Medical University Hospital, Department of Ophthalmology, Taichung, 402, Taiwan
| | - Chia-Rong Lee
- National Cheng Kung University, Department of Photonics, Tainan, 701, Taiwan
- National Cheng Kung University, Advanced Optoelectronics Technology Center, Tainan, 701, Taiwan
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Lee YH, Gou F, Peng F, Wu ST. Hysteresis-free and submillisecond-response polymer network liquid crystal. OPTICS EXPRESS 2016; 24:14793-14800. [PMID: 27410631 DOI: 10.1364/oe.24.014793] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We demonstrate a polymer network liquid crystal (PNLC) with negligible hysteresis while keeping submillisecond response time. By doping about 1% dodecyl acrylate (C12A) into the liquid crystal/monomer precursor, both hysteresis and residual birefringence are almost completely eliminated. The operating voltage and scattering properties remain nearly intact, but the tradeoff is enhanced double relaxation. This hysteresis-free PNLC should find applications in spatial light modulators, laser beam control, and optical communications in infrared region.
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