Dynamically manipulated lasing enabled by a reconfigured fingerprint texture of a cholesteric self-organized superstructure

Huang, Wenbin; Yuan, Cong‐Long; Shen, Dong; Zheng, Zhigang

doi:10.1039/c7tc02076g

Cited by 22 publications

(14 citation statements)

References 38 publications

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“…As we mentioned above, QDs are semiconductor nanoparticles with unique physical characteristics such as high quantum yields, large absorption cross-section, tunability of fluorescence emission, excellent colour purity, broad excitation spectra, good stability and long Light-driven phase transitions in LCs are a fascinating topic from both the scientific and the technological point of view. Apart from the photothermal effect [289], such phase transition can also be obtained by the photoisomerization ability of azo benzene dyes [290][291][292][293][294], which, at the same time, is also usually used for fabricating LC lasers [32,[295][296][297][298]. However, because these dyes are not nanoparticles, they will not be discussed within the framework of this review.…”

Section: Photonic Applicationsmentioning

confidence: 99%

Perspectives in Liquid-Crystal-Aided Nanotechnology and Nanoscience

2019

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The research field of liquid crystals and their applications is recently changing from being largely focused on display applications and optical shutter elements in various fields, to quite novel and diverse applications in the area of nanotechnology and nanoscience. Functional nanoparticles have recently been used to a significant extent to modify the physical properties of liquid crystals by the addition of ferroelectric and magnetic particles of different shapes, such as arbitrary and spherical, rods, wires and discs. Also, particles influencing optical properties are increasingly popular, such as quantum dots, plasmonic, semiconductors and metamaterials. The self-organization of liquid crystals is exploited to order templates and orient nanoparticles. Similarly, nanoparticles such as rods, nanotubes and graphene oxide are shown to form lyotropic liquid crystal phases in the presence of isotropic host solvents. These effects lead to a wealth of novel applications, many of which will be reviewed in this publication. the observation of chirality from achiral molecules, resulting from sterically induced packing of the bent-core mesogens [10], such as ferroelectricity or the formation of helical superstructures in the B7 phase [14]. Thermotropic LCs are commonly constituted by single organic entities or mixtures thereof, which exhibit various mesophases at different temperatures or pressures [15], illustrated in Figure 1b. As the temperature rises, a typical thermotropic LC passes through higher ordered phases, also called soft crystals, the hexatic smectic phases with positional order as well as bond orientational order, through the fluid smectic phases (SmC and SmA), which exhibit both positional and orientational order, and finally to the nematic phase (N) with purely orientational order, into the isotropic phase. The number of different phases observed depends on the chemical composition, symmetry and order of the LC molecules. About 25 different thermotropic phases are known to date, and they are still increasing in number. Appl. Sci. 2019, 9, x FOR PEER REVIEW 2 of 47 unique effects of the observation of chirality from achiral molecules, resulting from sterically induced packing of the bent-core mesogens [10], such as ferroelectricity or the formation of helical superstructures in the B7 phase [14]. Thermotropic LCs are commonly constituted by single organic entities or mixtures thereof, which exhibit various mesophases at different temperatures or pressures [15], illustrated in Figure 1b. As the temperature rises, a typical thermotropic LC passes through higher ordered phases, also called soft crystals, the hexatic smectic phases with positional order as well as bond orientational order, through the fluid smectic phases (SmC and SmA), which exhibit both positional and orientational order, and finally to the nematic phase (N) with purely orientational order, into the isotropic phase. The number of different phases observed depends on the chemical composition, symmetry and order of the LC molecules. About...

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Section: Photonic Applicationsmentioning

confidence: 99%

Perspectives in Liquid-Crystal-Aided Nanotechnology and Nanoscience

2019

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“…Strangi et al demonstrated thermally controllable lasing wavelength and electrically controllable emission intensity in CLC laser arrays fabricated by confining the CLC in holographically patterned polymer microchannels . Recently, lasing in the fingerprint texture of CLCs has been demonstrated where the laser emission direction can be switched between two orthogonal directions . The emission wavelength and lasing mode can be manipulated with a comparatively low external electric stimulation.…”

Section: Uniform Lying Helix Structurementioning

confidence: 99%

Stimuli‐Driven Control of the Helical Axis of Self‐Organized Soft Helical Superstructures

2018

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Supramolecular and macromolecular functional helical superstructures are ubiquitous in nature and display an impressive catalog of intriguing and elegant properties and performances. In materials science, self-organized soft helical superstructures, i.e., cholesteric liquid crystals (CLCs), serve as model systems toward the understanding of morphology- and orientation-dependent properties of supramolecular dynamic helical architectures and their potential for technological applications. Moreover, most of the fascinating device applications of CLCs are primarily determined by different orientations of the helical axis. Here, the control of the helical axis orientation of CLCs and its dynamic switching in two and three dimensions using different external stimuli are summarized. Electric-field-, magnetic-field-, and light-irradiation-driven orientation control and reorientation of the helical axis of CLCs are described and highlighted. Different techniques and strategies developed to achieve a uniform lying helix structure are explored. Helical axis control in recently developed heliconical cholesteric systems is examined. The control of the helical axis orientation in spherical geometries such as microdroplets and microshells fabricated from these enticing photonic fluids is also explored. Future challenges and opportunities in this exciting area involving anisotropic chiral liquids are then discussed.

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“…[100,201,[205][206][207][208][209][210][211][212] These controllable actions enable CLCs to be used in ground-breaking devices and application. This is because they possess a self-organized helical structure that can be controlled and switched by many stimuli.…”

Section: Cholesteric Lcsmentioning

confidence: 99%

“…This is because they possess a self-organized helical structure that can be controlled and switched by many stimuli. [100,201,[205][206][207][208][209][210][211][212] These controllable actions enable CLCs to be used in ground-breaking devices and application. In general, most of the applications come from the fact that external stimuli cause pitch changes [213][214][215][216][217] and helical axis switching, [33,35] both resulting in remarkable mesoscopic changes that qualify incredible well as diffraction gratings.…”

Section: Cholesteric Lcsmentioning

confidence: 99%

Dynamic Control of Light Direction Enabled by Stimuli‐Responsive Liquid Crystal Gratings

et al. 2018

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the duality consolidation, the idea of controlling light and how it interacts with matter has always been an exciting topic. Visible light, as we perceive it, is a small portion of the electromagnetic spectrum composed of mutually perpendicular oscillating electric and magnetic fields that propagate through space and presents wave-like and particle-like behavior. Since the elements comprising matter possess dynamic electron clouds, the electromagnetic nature of light prompts different responses when it interacts with different materials, depending on its intensity, frequency, the arrangement of molecules, and so on. Whenever light interacts with matter, it might be absorbed, re-emitted, scattered, or transmitted. Although these effects are well known, the combination of them with new, innovative materials pushes optics forward. In fact, advances in optics have often occurred through the development of materials with improved optical properties, thus creating remarkable applications that tremendously influence our daily lives. These exciting applications include image processing and recording, lasing, data storage, display devices, detector systems, propulsion systems, and optical tweezers, which have enabled remote micromanipulation of colloidal particles and promising applications in various biomedical and biological applications. [1][2][3] There is, however, one component that stands out: the diffraction grating. It is generally regarded as one of the most important devices in the development of several fields of science. [4] Such importance comes from the fact that a diffraction grating is a device with a periodic structure capable of changing the propagation and splitting the spectrum The ability to control light direction with tailored precision via facile means is long-desired in science and industry. With the advances in optics, a periodic structure called diffraction grating gains prominence and renders a more flexible control over light propagation when compared to prisms. Today, diffraction gratings are common components in wavelength division multiplexing devices, monochromators, lasers, spectrometers, media storage, beam steering, and many other applications. Next-generation optical devices, however, demand nonmechanical, full and remote control, besides generating higher than 1D diffraction patterns with as few optical elements as possible. Liquid crystals (LCs) are great candidates for light control since they can form various patterns under different stimuli, including periodic structures capable of behaving as diffraction gratings. The characteristics of such gratings depend on several physical properties of the LCs such as film thickness, periodicity, and molecular orientation, all resulting from the internal constraints of the sample, and all of these are easily controllable. In this review, the authors summarize the research and development on stimuli-controllable diffraction gratings and beam steering using LCs as the active optical materials. Dynamic gratings fabricated by applying external f...

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Dynamically manipulated lasing enabled by a reconfigured fingerprint texture of a cholesteric self-organized superstructure

Abstract: Laser emission based on an electrically reconfigured fingerprint texture of a cholesteric liquid crystal helical superstructure is achieved by judiciously designing the composition of the device material and the device structure.

Cited by 22 publications

References 38 publications

Perspectives in Liquid-Crystal-Aided Nanotechnology and Nanoscience

Perspectives in Liquid-Crystal-Aided Nanotechnology and Nanoscience

Stimuli‐Driven Control of the Helical Axis of Self‐Organized Soft Helical Superstructures

Dynamic Control of Light Direction Enabled by Stimuli‐Responsive Liquid Crystal Gratings

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