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Saadaoui L, Yang D, Wang Y, Hassan F, Drevensek-Olenik I, Zhang X, Gan Z, Li Y, Xu J. Electrically Tunable Two-Color Cholesteric Laser. Polymers (Basel) 2023; 15:4656. [PMID: 38139908 PMCID: PMC10747753 DOI: 10.3390/polym15244656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 11/21/2023] [Accepted: 12/07/2023] [Indexed: 12/24/2023] Open
Abstract
Two-color lasing emission from an asymmetric structure, consisting of two dye-doped cholesteric liquid crystal (DD-CLC) layers separated by a transparent interlayer, is demonstrated. The DD-CLC mixtures have different reflection bands with long-wavelength band edges located at the green and red wavelengths of the visible spectrum, respectively. For the laser action, the CLC hosts provide the feedback, and the fluorescent laser dyes represent the active medium. When the stacked structure is optically pumped above the threshold, two simultaneous laser lines separated by 123 nm are observed at the long-wavelength band edges of the DD-CLC mixtures. The influence of an electric field on lasing behavior is also analyzed and discussed in terms of the reflection spectrum and laser action. The results show a reversible tuning of the reflection band, accompanied by a modification of the lasing characteristics under the application of an external field. Above a specific threshold voltage, one of the emission lines is suppressed and the other is conserved. With a further increase in the voltage, both laser emissions are entirely inhibited. The investigated structure demonstrates a simple technique to obtain an electrically tunable multi-wavelength laser, which might pave the way for a new generation of organic laser sources.
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Affiliation(s)
- Lotfi Saadaoui
- The MOE Key Laboratory of Weak-Light Nonlinear Photonics and International Sino-Slovenian Join Research Center on Liquid Crystal Photonics, TEDA Institute of Applied Physics and School of Physics, Nankai University, Tianjin 300457, China; (L.S.); (D.Y.); (Y.W.); (F.H.); (Z.G.); (Y.L.); (J.X.)
- Physics Laboratory of Soft Matter and Electromagnetic Modelling, Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis 2092, Tunisia
| | - Donghao Yang
- The MOE Key Laboratory of Weak-Light Nonlinear Photonics and International Sino-Slovenian Join Research Center on Liquid Crystal Photonics, TEDA Institute of Applied Physics and School of Physics, Nankai University, Tianjin 300457, China; (L.S.); (D.Y.); (Y.W.); (F.H.); (Z.G.); (Y.L.); (J.X.)
| | - Yu Wang
- The MOE Key Laboratory of Weak-Light Nonlinear Photonics and International Sino-Slovenian Join Research Center on Liquid Crystal Photonics, TEDA Institute of Applied Physics and School of Physics, Nankai University, Tianjin 300457, China; (L.S.); (D.Y.); (Y.W.); (F.H.); (Z.G.); (Y.L.); (J.X.)
| | - Faheem Hassan
- The MOE Key Laboratory of Weak-Light Nonlinear Photonics and International Sino-Slovenian Join Research Center on Liquid Crystal Photonics, TEDA Institute of Applied Physics and School of Physics, Nankai University, Tianjin 300457, China; (L.S.); (D.Y.); (Y.W.); (F.H.); (Z.G.); (Y.L.); (J.X.)
| | - Irena Drevensek-Olenik
- Faculty of Mathematics and Physics, University of Ljubljana, SI-1000 Ljubljana, Slovenia
- Department of Complex Matter, J. Stefan Institute, SI-1000 Ljubljana, Slovenia
| | - Xinzheng Zhang
- The MOE Key Laboratory of Weak-Light Nonlinear Photonics and International Sino-Slovenian Join Research Center on Liquid Crystal Photonics, TEDA Institute of Applied Physics and School of Physics, Nankai University, Tianjin 300457, China; (L.S.); (D.Y.); (Y.W.); (F.H.); (Z.G.); (Y.L.); (J.X.)
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
| | - Zenghua Gan
- The MOE Key Laboratory of Weak-Light Nonlinear Photonics and International Sino-Slovenian Join Research Center on Liquid Crystal Photonics, TEDA Institute of Applied Physics and School of Physics, Nankai University, Tianjin 300457, China; (L.S.); (D.Y.); (Y.W.); (F.H.); (Z.G.); (Y.L.); (J.X.)
| | - Yigang Li
- The MOE Key Laboratory of Weak-Light Nonlinear Photonics and International Sino-Slovenian Join Research Center on Liquid Crystal Photonics, TEDA Institute of Applied Physics and School of Physics, Nankai University, Tianjin 300457, China; (L.S.); (D.Y.); (Y.W.); (F.H.); (Z.G.); (Y.L.); (J.X.)
| | - Jingjun Xu
- The MOE Key Laboratory of Weak-Light Nonlinear Photonics and International Sino-Slovenian Join Research Center on Liquid Crystal Photonics, TEDA Institute of Applied Physics and School of Physics, Nankai University, Tianjin 300457, China; (L.S.); (D.Y.); (Y.W.); (F.H.); (Z.G.); (Y.L.); (J.X.)
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Brown CM, Pakamoryte I, Hands PJW. Experimental study of the effect of pump pulse duration on liquid crystal laser performance. OPTICS LETTERS 2023; 48:4873-4876. [PMID: 37707925 DOI: 10.1364/ol.500009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 08/20/2023] [Indexed: 09/15/2023]
Abstract
Much work has been done to understand the factors that impact photonic band-edge liquid crystal (LC) laser threshold and slope efficiency, two parameters often stated to quantify performance. Conventionally, LC lasers are optically pumped using Q-switched lasers with a fixed pulse duration, and thus the effect of pump pulse duration on LC laser performance has received little attention. While some studies have been published at different pump pulse durations, these use different laser sources and experimental conditions, making the data incomparable. By exploiting a recent breakthrough in laser diode pumping, our experimental results prove and quantify the detrimental effect of an increase in pump pulse duration on LC laser performance. We also show that the dependency of threshold on pump pulse duration depends on how threshold is defined, owing to an ambiguity in the definition of pulse energy in systems where peak power and pulse duration can be independently controlled. For improved comparison within the literature on LC laser device performance, we thus propose an alternative convention, whereby threshold is stated in units of peak power density.
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Concellón A. Liquid Crystal Emulsions: A Versatile Platform for Photonics, Sensing, and Active Matter. Angew Chem Int Ed Engl 2023:e202308857. [PMID: 37694542 DOI: 10.1002/anie.202308857] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/12/2023] [Accepted: 09/11/2023] [Indexed: 09/12/2023]
Abstract
The self-assembly of liquid crystals (LCs) is a fascinating method for controlling the organization of discrete molecules into nanostructured functional materials. Although LCs are traditionally processed in thin films, their confinement within micrometre-sized droplets has recently revealed new properties and functions, paving the way for next-generation soft responsive materials. These recent findings have unlocked a wealth of unprecedented applications in photonics (e.g. reflectors, lasing materials), sensing (e.g. biomolecule and pathogen detection), soft robotics (e.g. micropumps, artificial muscles), and beyond. This Minireview focuses on recent developments in LC emulsion designs and highlights a variety of novel potential applications. Perspectives on the opportunities and new directions for implementing LC emulsions in future innovative technologies are also provided.
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Affiliation(s)
- Alberto Concellón
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, C/Pedro Cerbuna 12, 50009, Zaragoza, Spain
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Chang TK, Tseng YY, Wu PC, Lee MJ, Lee W. Optical and flexoelectric biosensing based on a hybrid-aligned liquid crystal of anomalously small bend elastic constant. Biosens Bioelectron 2023; 232:115314. [PMID: 37086565 DOI: 10.1016/j.bios.2023.115314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 03/15/2023] [Accepted: 04/08/2023] [Indexed: 04/24/2023]
Abstract
Liquid crystal (LC)-based biosensors rely on the response of the LC molecules to perturbation generated by analytes at the interface, leading to the susceptible change in molecular alignment or orientation. The sensitivity of these biosensors is primarily dependent on the LC's material properties and surface anchoring strength. By incorporation of an unconventional mesogenic compound (CB7CB) coupled with the hybrid-alignment cell configuration, this work presents a binary nematic LC for label-free biosensing, manifesting a novel sensing technology that takes advantage of CB7CB-induced flexoelectricity in the transducer. Herein, we prepared LC mixtures by blending a typical rod-like nematic LC (E7) with the bent-core mesogen CB7CB in various weight ratios and studied the effect of the CB7CB content on E7/CB7CB-based biosensing performance in vertically aligned and hybrid-aligned nematic (HAN) cells. Owing to the anomalously small bend elastic constant K33 in CB7CB, the mixture designated CB45 with the highest CB7CB weight percentage (45 wt% in this study) was best applicable to biosensing in HAN cells. When observed under a polarizing optical microscope, CB45 in the HAN geometry showed the capability of detection of as low as 10-10 g/mL for the protein standard bovine serum albumin (BSA). Moreover, the quantitation of the assay was fulfilled by both dielectric and light transmission measurements of the hybrid-aligned cholesteric CB45/R5011. The limit of detection of 7 × 10-10 g/mL was achieved by spectrometric analysis. To the best of our knowledge, this work is the first to demonstrate flexoelectric biosensing on the basis of flexoelectric polarization associated with giant flexoelectricity in CB7CB partially constituting the LC transducer.
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Affiliation(s)
- Tsung-Keng Chang
- College of Photonics, National Yang Ming Chiao Tung University, Guiren Dist, Tainan, 711010, Taiwan; National Laboratory Animal Center, National Applied Research Laboratories, Taipei, 115202, Taiwan
| | - Yung-Yu Tseng
- Institute of Photonic System, National Yang Ming Chiao Tung University, Guiren Dist, Tainan, 711010, Taiwan
| | - Po-Chang Wu
- Institute of Imaging and Biomedical Photonics, College of Photonics, National Yang Ming Chiao Tung University, Guiren Dist, Tainan, 711010, Taiwan
| | - Mon-Juan Lee
- Department of Bioscience Technology, Chang Jung Christian University, Guiren Dist, Tainan, 711301, Taiwan; Department of Medical Science Industries, Chang Jung Christian University, Guiren Dist, Tainan, 711301, Taiwan.
| | - Wei Lee
- College of Photonics, National Yang Ming Chiao Tung University, Guiren Dist, Tainan, 711010, Taiwan; Institute of Imaging and Biomedical Photonics, College of Photonics, National Yang Ming Chiao Tung University, Guiren Dist, Tainan, 711010, Taiwan.
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Li S, Zhou X, Zhu J, Du K, Du Y, Gao H. Local chiral inversion of chiral nematic liquid crystals in cylinders. Phys Rev E 2023; 107:034705. [PMID: 37073040 DOI: 10.1103/physreve.107.034705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 03/03/2023] [Indexed: 04/20/2023]
Abstract
On the basis of Landau-de Gennes theory and the finite-difference iterative method, the autonomic modulation of chiral inversion in a cylindrical cavity with degenerate planar anchoring is investigated. Under the applied helical twisting power (inversely related to the pitch P), a chiral inversion can be achieved due to the nonplanar geometry effect, and the inversion capacity rises with the increase of the helical twisting power. The combined effect of the saddle-splay K_{24} contribution (corresponding to the L_{24} term in Landau-de Gennes theory) and the helical twisting power are analyzed. It is found that the chiral inversion is more strongly modulated on the condition that the chirality of spontaneous twist is opposite to that of applied helical twisting power. Further, larger values of K_{24} will induce larger modulation of the twist degree and smaller modulation of the inverted region. The autonomic modulation of chiral inversion shows great potential for chiral nematic liquid crystal materials to be used in smart devices, such as light-controlled switches and nanoparticle transporters.
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Affiliation(s)
- Shuting Li
- School of Science, Hebei University of Technology, Tianjin 300401, People Republic of China
| | - Xuan Zhou
- School of Science, Hebei University of Technology, Tianjin 300401, People Republic of China
| | - Jiliang Zhu
- School of Science, Hebei University of Technology, Tianjin 300401, People Republic of China
| | - Kaiyang Du
- School of Science, Hebei University of Technology, Tianjin 300401, People Republic of China
| | - Yike Du
- School of Science, Hebei University of Technology, Tianjin 300401, People Republic of China
| | - Han Gao
- School of Science, Hebei University of Technology, Tianjin 300401, People Republic of China
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6
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Qu G, Zhang X, Li S, Lu L, Gao J, Yu B, Wu S, Zhang Q, Hu Z. Liquid crystal random lasers. Phys Chem Chem Phys 2022; 25:48-63. [PMID: 36477742 DOI: 10.1039/d2cp02859j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
The enthusiasm for research on liquid crystal random lasers (LCRLs) is driven by their unusual optical properties and promising potential for broad applications in manufacturing, communications, medicine and entertainment. From this perspective, we will summarize the most attractive advances in the development of LCRLs in the last decade and propose future prospects. This article will begin with a fundamental description of LCRLs, including the principle of laser generation and a description of LC substances. Then, we spend several chapters on the lasing performance control methods of LCRLs, including random lasing wavelength, threshold, and polarization properties. In addition, we analyze how the LC chiral agent structures, LC core-shell structures and new light-amplifying materials affect the design of LCRL devices. In the last chapter, we discuss the application of LCRLs in 3D displays, information encryption, biochemical sensing and other optoelectronics devices and finally end the perspective with LCRLs' likely directions in future research.
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Affiliation(s)
- Guangyin Qu
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Information Materials and Intelligent Sensing Laboratory of Anhui Province, School of Physics and Optoelectronic Engineering, Anhui University, Hefei 230601, China.
| | - Xiaojuan Zhang
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Information Materials and Intelligent Sensing Laboratory of Anhui Province, School of Physics and Optoelectronic Engineering, Anhui University, Hefei 230601, China.
| | - Siqi Li
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Information Materials and Intelligent Sensing Laboratory of Anhui Province, School of Physics and Optoelectronic Engineering, Anhui University, Hefei 230601, China.
| | - Liang Lu
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Information Materials and Intelligent Sensing Laboratory of Anhui Province, School of Physics and Optoelectronic Engineering, Anhui University, Hefei 230601, China.
| | - Jiangang Gao
- Department of Polymeric Materials and Engineering, School of Biological and Chemical Engineering, Anhui Polytechnic University, Wuhu, 241000, Anhui, China
| | - Benli Yu
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Information Materials and Intelligent Sensing Laboratory of Anhui Province, School of Physics and Optoelectronic Engineering, Anhui University, Hefei 230601, China.
| | - Si Wu
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026, China.
| | - Qijin Zhang
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026, China.
| | - Zhijia Hu
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Information Materials and Intelligent Sensing Laboratory of Anhui Province, School of Physics and Optoelectronic Engineering, Anhui University, Hefei 230601, China.
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7
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Mohammadimasoudi M, Geiregat P, Van Acker F, Beeckman J, Hens Z, Aubert T, Neyts K. Quantum dot lasing from a waterproof and stretchable polymer film. LIGHT, SCIENCE & APPLICATIONS 2022; 11:275. [PMID: 36104330 PMCID: PMC9475037 DOI: 10.1038/s41377-022-00960-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 08/03/2022] [Accepted: 08/17/2022] [Indexed: 06/15/2023]
Abstract
Colloidal quantum dots (QDs) are excellent optical gain materials that combine high material gain, a strong absorption of pump light, stability under strong light exposure and a suitability for solution-based processing. The integration of QDs in laser cavities that fully exploit the potential of these emerging optical materials remains, however, a challenge. In this work, we report on a vertical cavity surface emitting laser, which consists of a thin film of QDs embedded between two layers of polymerized chiral liquid crystal. Forward directed, circularly polarized defect mode lasing under nanosecond-pulsed excitation is demonstrated within the photonic band gap of the chiral liquid crystal. Stable and long-term narrow-linewidth lasing of an exfoliated free-standing, flexible film under water is obtained at room temperature. Moreover, we show that the lasing wavelength of this flexible cavity shifts under influence of pressure, strain or temperature. As such, the combination of solution processable and stable inorganic QDs with high chiral liquid crystal reflectivity and effective polymer encapsulation leads to a flexible device with long operational lifetime, that can be immersed in different protic solvents to act as a sensor.
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Affiliation(s)
- Mohammad Mohammadimasoudi
- Nano-Bio-Photonics Lab, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran.
- Liquid Crystals and Photonics Group, ELIS Department, Ghent University, Technologiepark-Zwijnaarde 126, 9052, Zwijnaarde, Belgium.
| | - Pieter Geiregat
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Ghent, Belgium
- Center for Nano- and Biophotonics (NB-Photonics), Ghent University, Technologiepark-Zwijnaarde 126, 9052, Zwijnaarde, Belgium
| | - Frederik Van Acker
- Liquid Crystals and Photonics Group, ELIS Department, Ghent University, Technologiepark-Zwijnaarde 126, 9052, Zwijnaarde, Belgium
- Center for Nano- and Biophotonics (NB-Photonics), Ghent University, Technologiepark-Zwijnaarde 126, 9052, Zwijnaarde, Belgium
| | - Jeroen Beeckman
- Liquid Crystals and Photonics Group, ELIS Department, Ghent University, Technologiepark-Zwijnaarde 126, 9052, Zwijnaarde, Belgium
- Center for Nano- and Biophotonics (NB-Photonics), Ghent University, Technologiepark-Zwijnaarde 126, 9052, Zwijnaarde, Belgium
| | - Zeger Hens
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Ghent, Belgium
- Center for Nano- and Biophotonics (NB-Photonics), Ghent University, Technologiepark-Zwijnaarde 126, 9052, Zwijnaarde, Belgium
| | - Tangi Aubert
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Ghent, Belgium
- Center for Nano- and Biophotonics (NB-Photonics), Ghent University, Technologiepark-Zwijnaarde 126, 9052, Zwijnaarde, Belgium
| | - Kristiaan Neyts
- Liquid Crystals and Photonics Group, ELIS Department, Ghent University, Technologiepark-Zwijnaarde 126, 9052, Zwijnaarde, Belgium
- Center for Nano- and Biophotonics (NB-Photonics), Ghent University, Technologiepark-Zwijnaarde 126, 9052, Zwijnaarde, Belgium
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Mohammadimasoudi M, Khoshkhati F, Sohrabnavi H, Neyts K. Fabrication of a spatially tunable band reject filter with a very wide tunability range based on a chiral nematic liquid crystal polymer. OPTICS LETTERS 2022; 47:3760-3763. [PMID: 35913308 DOI: 10.1364/ol.464754] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 07/06/2022] [Indexed: 06/15/2023]
Abstract
A thin, waterproof, and stable spatially tunable band reject filter is fabricated based on a chiral nematic liquid crystal polymer. The fabrication method for this filter is new, to the best of our knowledge, and straightforward. The photonic bandgap (PBG) of the proposed filter can be tuned from 350 nm to 760 nm by a mechanical movement of 6.5 mm. The filter reflects almost 50% of unpolarized incident light in the PBG and remains practically transparent for other wavelengths. The filter remains stable for four years and has acceptable resistance to polar protic solvents and thermal stability up to 90°C. The filter can be detached from the glass substrates, to be used as a thin 8-µm free-standing film or to be attached to a flexible substrate. This spatial tunable band reject filter may be used in displays, optical devices, and optical communication.
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Multimode Robust Lasing in a Dye-Doped Polymer Layer Embedded in a Wedge-Shaped Cholesteric. Molecules 2021; 26:molecules26196089. [PMID: 34641632 PMCID: PMC8512166 DOI: 10.3390/molecules26196089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/29/2021] [Accepted: 08/30/2021] [Indexed: 11/26/2022] Open
Abstract
Cholesteric liquid crystals (CLCs) with induced defects are one of the most prominent materials to realize compact, low-threshold and tunable coherent light sources. In this context, the investigation of optical properties of induced defect modes in such CLCs is of great interest. In particular, many studies have been devoted to the spectral control of the defect modes depending on their thickness, optical properties, distribution along the CLC, etc. In this paper, we investigate the lasing possibilities of a dye-doped polymer layer embedded in a wedge-shaped CLC. We show that multimode laser generation is possible due to the observed multiple defect modes in the PBG that enlarges the application range of the system. Furthermore, our simulations based on a Berreman 4 × 4 matrix approach for a wide range of CLC thickness show both periodic and continuous generation of defect modes along particular spectral lines inside the PBG. Such a robust spectral behaviour of induced defect modes is unique, and, to our knowledge, is not observed in similar CLC-based structures.
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Palto SP, Geivandov AR, Kasyanova IV, Simdyankin IV, Artemov VV, Gorkunov MV. Liquid crystal microlenses based on binary surface alignment controlled by focused ion beam treatment. OPTICS LETTERS 2021; 46:3376-3379. [PMID: 34264217 DOI: 10.1364/ol.426904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 06/11/2021] [Indexed: 06/13/2023]
Abstract
We report the formation of high optical power microlenses in the near-surface region of the liquid crystal layer. Such microlenses, possessing a very small focal length f at a rather large aperture A (f/A∼2), are able to focus the light into spots of a characteristic size comparable with the wavelength. Using numerical modeling, a specific patterning profile of a liquid crystal (LC) alignment surface by an ion beam is proposed to provide the aligning properties necessary for the formation of an array of microlenses with a focal length comparable to the LC cell thickness. The proposed microlens arrays are produced, and their optical properties are discussed.
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11
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Lin W, Nie Q, Jiang XF, Jiang X, Wang K, Shui L, Priya S, Zhou G, Hu X. Synthesis of Perovskite Nanocrystals and Their Photon-Emission Application in Conjunction With Liquid Crystals. Front Chem 2020; 8:574. [PMID: 32850620 PMCID: PMC7399476 DOI: 10.3389/fchem.2020.00574] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 06/04/2020] [Indexed: 11/13/2022] Open
Abstract
Perovskite nanocrystals have attracted worldwide attention due to their outstanding optical versatility, high photoluminescence quantum yields, and facile synthesis. In this review, we firstly revisit the synthetic methods for perovskite nanocrystals (PNCs), including hot injection, anion exchange, solvothermal reaction, etc. In the meantime, we discuss effects of the different synthetic methods on the properties of PNCs, including the crystal size, emission spectral feature, quantum yield, etc., followed by several optimizing strategies. Finally, lasing and display applications of these PNCs in combination with liquid crystal materials are discussed thoroughly. Outlooks on the challenges and opportunities of these nanocrystalline materials in terms of adjunct applications with liquid crystals have been presented at the end, which are highly promising for next-generation light emission applications.
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Affiliation(s)
- Weixi Lin
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China.,SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, China
| | - Qiumei Nie
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China.,SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, China
| | - Xiao-Fang Jiang
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
| | - Xinshuai Jiang
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
| | - Kai Wang
- Material Research Institute, Pennsylvania State University, University Park, PA, United States
| | - Lingling Shui
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
| | - Shashank Priya
- Material Research Institute, Pennsylvania State University, University Park, PA, United States
| | - Guofu Zhou
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China.,SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, China.,Academy of Shenzhen Guohua Optoelectronics, Shenzhen, China
| | - Xiaowen Hu
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China.,SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, China
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12
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Shtykov NM, Palto SP, Geivandov AR, Umanskii BA, Simdyankin IV, Rybakov DO, Artemov VV, Gorkunov MV. Lasing in liquid crystal systems with a deformed lying helix. OPTICS LETTERS 2020; 45:4328-4331. [PMID: 32735290 DOI: 10.1364/ol.394430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 06/30/2020] [Indexed: 06/11/2023]
Abstract
We report on experimental investigations of the lasing effect in novel chiral liquid crystal (CLC) systems with a deformed lying helix (DLH). The lasing is studied for both odd- and even-order field-induced stop-bands, which are characteristic exclusively of the DLH state. The DLH state is achieved in special CLC cells with periodic boundary conditions, when the surface alignment is flipped between planar and vertical states. The alignment surfaces are prepared using focused ion-beam lithography. In an electric field, such CLC systems undergo an orientational transition, when the initial Grandjean-plane texture with the helix axis perpendicular to the CLC layer is transformed into the DLH state with the helix axis oriented in the plane of the layer. Due to field-induced strong deformation, the DLH system is characterized by a set of photonic stop-bands with a fine spectral structure; namely, on these fine-structured sub-bands, we have observed and studied the low-threshold lasing effect.
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Choi HJ, Bae JH, Bae S, Lee JJ, Nishikawa H, Araoka F, Choi SW. Development of a liquid crystal laser using a simple cubic liquid crystalline blue phase platform. RSC Adv 2019; 9:32922-32927. [PMID: 35529721 PMCID: PMC9073273 DOI: 10.1039/c9ra07460k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 10/08/2019] [Indexed: 11/21/2022] Open
Abstract
A liquid crystal laser using a polymer-stabilized simple cubic blue phase (BPII) platform has been scarcely reported because the polymer stabilization of a BPII is relatively difficult compared to that of a body-centered-cubic BP (BPI). In this study, we succeeded in fabricating a dye-doped polymer-stabilized BPII laser with wide operating-temperature ranges over 15 °C including room temperature. A narrow and sharp single laser peak with a full width at half maximum of approximately 2 nm was derived from the photonic band edge effect of the BPII-distributed feedback optical resonator. As a result, the laser emission was a circularly polarized light, which matched the chirality of the proposed pure BPII.
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Affiliation(s)
- Hyeon-Joon Choi
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin-shi Gyeonggi-do 17104 Korea
| | - Jae-Hyun Bae
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin-shi Gyeonggi-do 17104 Korea
| | - Sangwok Bae
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin-shi Gyeonggi-do 17104 Korea
| | - Jae-Jin Lee
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin-shi Gyeonggi-do 17104 Korea
| | - Hiroya Nishikawa
- Physicochemical Soft Matter Research Team, RIKEN Center for Emergent Matter Science (CEMS) Wako Saitama 351 0198 Japan
| | - Fumito Araoka
- Physicochemical Soft Matter Research Team, RIKEN Center for Emergent Matter Science (CEMS) Wako Saitama 351 0198 Japan
| | - Suk-Won Choi
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin-shi Gyeonggi-do 17104 Korea
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14
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Eun J, Kim SJ, Jeong J. Effects of chiral dopants on double-twist configurations of lyotropic chromonic liquid crystals in a cylindrical cavity. Phys Rev E 2019; 100:012702. [PMID: 31499771 DOI: 10.1103/physreve.100.012702] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Indexed: 06/10/2023]
Abstract
We investigate how chiral dopants affect the chiral symmetry breaking of lyotropic chromonic liquid crystals (LCLCs) focusing on the double-twist (DT) director configurations in a cylindrical capillary. LCLCs of unusual elastic properties tend to exhibit chiral director configurations under confinement despite the absence of intrinsic chirality. The DT director configuration in a cylindrical cavity with a degenerate planar anchoring, resulting from the large saddle-splay-to-twist elastic modulus ratio, is a representative example. Here we start by reexamining the DT configuration of nematic disodium cromoglycate in a cylindrical capillary and estimate the ratio of saddle splay to bend modulus K_{24}/K_{3}=0.5±0.1. Additionally, we study the DT configurations of the chiral nematic LCLCs with chiral dopants. The DT configuration becomes homochiral when the dopant concentration surpasses the critical concentration. We characterize these chiral DT configurations and provide a theoretical model on their energetics. Finally, we observe how the enantiomeric excess of chiral dopants determines the director configuration when dopants of two different handednesses are mixed.
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Affiliation(s)
- Jonghee Eun
- Department of Physics, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Sung-Jo Kim
- Center for Soft and Living Matter, Institute for Basic Science, Ulsan, Republic of Korea
| | - Joonwoo Jeong
- Department of Physics, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
- Center for Soft and Living Matter, Institute for Basic Science, Ulsan, Republic of Korea
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15
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Neyts K, Dadalyan T, Van Acker F, Nys I, Beeckman J. Mode coupling by scattering in chiral nematic liquid crystal ring lasing. OPTICS EXPRESS 2019; 27:8081-8091. [PMID: 31052633 DOI: 10.1364/oe.27.008081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 12/04/2018] [Indexed: 06/09/2023]
Abstract
Lasing in dye-doped chiral nematic liquid crystal can be realized with low pump energy and relatively high efficiency, thanks to the high reflectivity of the periodic structure. When the helical axis is oriented perpendicular to the substrates, the main lasing peak is normal to the substrates. In some cases, ring lasing of a particular wavelength is observed into an emission cone with axial symmetry. In this paper we explain how scattering of light in the liquid crystal layer leads to optical coupling between normal modes and inclined modes. Based on a numerical model that takes into account spontaneous emission, gain and scattering we show that scattering leads to emission characteristics that are similar to experimental results.
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16
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Chen LJ, Dai JH, Lin JD, Mo TS, Lin HP, Yeh HC, Chuang YC, Jiang SA, Lee CR. Wavelength-Tunable and Highly Stable Perovskite-Quantum-Dot-Doped Lasers with Liquid Crystal Lasing Cavities. ACS APPLIED MATERIALS & INTERFACES 2018; 10:33307-33315. [PMID: 30198255 DOI: 10.1021/acsami.8b08474] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
This study applies a low-cost solvothermal method to synthesize all-inorganic (lead-free cesium tin halide) perovskite quantum dots (AIPQDs) and to fabricate AIPQD-doped lasers with cholesteric liquid crystal (CLC) lasing cavities. The lasers present highly qualified lasing features of low threshold (150 nJ/pulse) and narrow line width (0.20 nm) that are attributed to the conjunction of the suppression of photoluminescence (PL) loss caused by the quantum confinement of AIPQDs and the amplification of PL caused by the band-edge effect of the CLC-distributed feedback resonator. In addition, the lasers possess highly flexible lasing-wavelength tuning features and a long-term stability under storage at room temperature and under high humidity given the protective role of CLC. These advantages are difficult to confer to typical light-emitting perovskite devices. Given these merits, the AIPQD-doped CLC laser device has considerable potential applications in optoelectronic and photonic devices, including lighting, displays, and lasers.
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Affiliation(s)
| | | | | | - Ting-Shan Mo
- Department of Electronic Engineering , Kun Shan University of Technology , Tainan 710 , Taiwan
| | | | - Hui-Chen Yeh
- Graduate Institute of Electrical Engineering , National Kaohsiung University of Science and Technology , Kaohsiung 824 , Taiwan
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17
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Normand MC, Chen P, Can C, Hands PJW. Overcoming repetition rate limitations in liquid crystal laser systems. OPTICS EXPRESS 2018; 26:26544-26555. [PMID: 30469739 DOI: 10.1364/oe.26.026544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 09/10/2018] [Indexed: 06/09/2023]
Abstract
Liquid crystal lasers have advantageous features, including continuous wavelength tuning at low cost. Although many potential applications have been highlighted, use of these lasers is not widespread, partially due to performance limitations. This paper presents a method of overcoming repetition rate limitations. A rapidly spinning stage is used to allow operation of a LC laser at 10 kHz: two orders of magnitude greater than possible with a static cell. Average power outputs of up to 3.5 mW are achieved along with an improvement in emission stability. Lastly, a mechanical wavelength-switching method is demonstrated. The spinning cell approach will enable research into the use of liquid crystal lasers in fluorescence imaging and display applications.
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18
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Coupling of Defect Modes in Cholesteric Liquid Crystals Separated by Isotropic Polymeric Layers. Polymers (Basel) 2018; 10:polym10070805. [PMID: 30960730 PMCID: PMC6403987 DOI: 10.3390/polym10070805] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 07/15/2018] [Accepted: 07/20/2018] [Indexed: 11/21/2022] Open
Abstract
Cholesteric liquid crystal structures with multiple isotropic defect layers exhibit localized optical modes (defect modes). Coupling effects between these modes were simulated using the finite difference time domain method. Analogous to the well-known result of the tight-binding approximation in solid state physics, splitting of the defect modes takes place, as soon as the structure contains more than one defect layer. The dispersion relation of the mini-bands forming within the photonic band gap of the structure is calculated numerically. The structures might have promising applications for multiwavelength filters and low-threshold lasers.
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