Article
Polymer Science
Muhammad Shahriyar Islam, Kah-Yoong Chan, Gregory Soon How Thien, Pei-Ling Low, Chu-Liang Lee, Sew Kin Wong, Ervina Efzan Mhd Noor, Benedict Wen-Cheun Au, Zi-Neng Ng
Summary: Polymer-dispersed liquid crystal (PDLC) film is becoming popular in the market due to its unique functionalities, including switchable tint capabilities and energy-saving features. However, there is still ambiguity regarding the performance of PDLC films, such as their sizing effects on light transmission, current consumption, and power consumption. This study investigates the sizing effects and varying applied voltage effect of PDLC films, and presents a cost-efficient film with optimal parameters, paving the way for large-scale adoption in commercial and residential premises.
Article
Chemistry, Multidisciplinary
Anna Margareta Risse, Juergen Schmidtke, Heinz-Siegfried Kitzerow
Summary: The study demonstrates the modulation of polychromatic mid-infrared radiation using a liquid crystal layer embedded between Germanium plates. The modulators show promising contrast ratios and response times, making them suitable for mid-infrared radiation control in applications such as chemical sensing.
Article
Crystallography
Junyu Zou, Qian Yang, En-Lin Hsiang, Haruki Ooishi, Zhuo Yang, Kifumi Yoshidaya, Shin-Tson Wu
Summary: The new nematic mixture features high birefringence, moderate dielectric anisotropy, low viscosity, and good photostability, making it suitable for various applications with fast response time.
Article
Optics
Dekang Chen, Stephen D. March, Andrew H. Jones, Yang Shen, Adam A. Dadey, Keye Sun, J. Andrew McArthur, Alec M. Skipper, Xingjun Xue, Bingtian Guo, Junwu Bai, Seth R. Bank, Joe C. Campbell
Summary: The development of mid-wave infrared photonics has led to a demand for high-performance photodetectors operating in this range. However, the high dark current in narrow-bandgap materials limits the signal-to-noise ratio of mid-wave infrared detection. To tackle this challenge, an avalanche photodiode design using photon-trapping structures is introduced, which enhances quantum efficiency and reduces dark current. The achieved results show significantly improved performance compared to previous photodiodes, with high quantum efficiency, low dark current, increased bandwidth, and gain-bandwidth product.
Article
Computer Science, Information Systems
Robert Guirado, Gerardo Perez-Palomino, Manuel Cano-Garcia, Morten A. Geday, Eduardo Carrasco
Summary: This paper addresses the slow response time of planar Liquid Crystal (LC)-based phase-shift metasurface and Reconfigurable Intelligent Surfaces (RIS) cells by introducing a polymer network LC (PNLC) mixture suitable at mm-wave bands. The effective anisotropic and uniaxial model for PNLC is experimentally validated at 100 GHz for the first time. The temporal performance and tunability of PNLC are compared with transmissive and reflective cells, showing significant improvement in response time at the expense of tunability reduction.
Article
Chemistry, Physical
Alfonso Martinez-Felipe, Daniel Zaton, Martin Castillo-Valles, Asia Baldini, Jonathan Pease, Natalie Leader, Nurul Fadhilah Kamalul Aripin, Marco Giacinti-Baschetti, M. Blanca Ros
Summary: In this study, we investigated the dielectric and conductivity response of three materials containing bent-core and tetra(ethyleneoxide) moieties, and their complexes doped with lithium triflate salts. The doped materials showed smectic mesophases and exhibited direct current conductivity at low frequencies. These materials have dynamic and dual character and have the potential to be used in new energy devices.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Review
Polymer Science
Yong Ye, Li Guo, Tingjun Zhong
Summary: Polymer-stabilized liquid crystals (PSLCs) are versatile materials with polymer networks providing anchoring energy for liquid crystals. This review details various improvements in PSLCs, including polymer-stabilized nematic, cholesteric, blue phase, smectic, ferroelectric, and antiferroelectric liquid crystals. PSLCs offer multiple functionalities, such as reorientation in smart windows and manual tuning of reflection bandwidth in broadband reflectors. PSBPLCs open up new possibilities for displays, modulators, sensors, lasers, lenses, and photonics applications. Polymer networks in PSFLCs or PSAFLCs enhance grayscale memories for flexible displays and energy-saving smart cards. The remaining challenges and research opportunities in PSLCs are also discussed.
Article
Nanoscience & Nanotechnology
Jody A. M. Lugger, Patricia P. Marin San Roman, Camiel C. E. Kroonen, Rint P. Sijbesma
Summary: A photoresponsive nanoporous polymer film was successfully produced, with azobenzoic acid undergoing trans-cis and cis-trans photoisomerizations. The cis isomer exhibited faster dye absorption kinetics, suggesting potential applications in molecular separation and sensing.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
Aleksandra Gridyakina, Natalia Kasian, Mi losz S. Chych Lowski, Marta Kajkowska, Piotr Lesiak
Summary: Multicomponent liquid crystal systems are of great interest in scientific research and practical applications. By combining liquid crystals, polymers, and nanoparticles into a three-component system, it is possible to optimize the performance in display applications and expand the applications of multicomponent systems.
MATERIALS TODAY PHYSICS
(2023)
Review
Chemistry, Multidisciplinary
Joshua Saczek, Xiaoxue Yao, Vladimir Zivkovic, Mohamed Mamlouk, Dan Wang, Stevin S. Pramana, Steven Wang
Summary: Liquid marbles encapsulate various liquids with hydrophobic particles, providing isolation from the external environment, but face limitations in lifetime and robustness. By manipulating particle characteristics and environments, improvements in stability can be achieved. Emerging applications such as unconventional computing, cell mimicry, and soft lithography benefit from liquid marble technology.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Shuang Tian, Jihua Tan, Tianxing Kang, Chen Cao, Jie Pan, Yafang Xiao, Xiao Cui, Shengliang Li, Chun-Sing Lee
Summary: This study discovers that the library of NIR-transparent organic materials can be expanded by forming a charge-transfer complex (CTC) between commercially available donor (D) and acceptor (A) molecules. By regulating the D-A interaction, the CTC filter shows tunable absorption from visible to NIR region with high penetration of NIR radiation. It can successfully highlight NIR information and provide a convenient tool for anti-counterfeiting and viewing protected NIR information.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Physical
Qing Xia, Jiaze Yin, Zhongyue Guo, Ji-Xin Cheng
Summary: Midinfrared photothermal microscopy is an emerging tool for bond-selective chemical imaging of living biological and material samples. With high resolution, spectral fidelity, and reduced water absorption background, it overcomes the limitations of traditional infrared chemical imaging methods. This review summarizes its principle, contrast origins, recent technology development, and broad applications in life science and material characterization, and provides a perspective of future technical advances.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Materials Science, Multidisciplinary
J. Omachi, N. Naka, K. Yoshioka, M. Kuwata-Gonokami
Summary: In this study, we investigated the dynamic properties of the electron-hole state in electron-hole droplets (EHDs) using dielectric response measurements. We found that the surface plasmon resonance of EHDs and the electron-hole Coulomb interaction had a significant impact on the dynamic dielectric response. The carrier density inside EHDs remained constant, while the decay time of the condensed volume was short and the AC conductivity relaxation rate was the highest among group-IV semiconductors during the nanosecond timescale.
Article
Chemistry, Analytical
Ji-Sook Lim, Ye-Ji Kim, Soo-Young Park
Summary: The CLCsolid balls exhibit excellent elastic properties suitable for small strain sensors, while the CLCsolid-IPN balls show pH-responsive color change, which can be applied for small pH sensors. Immobilizing urease on the CLCsolid-IPN balls enables their use as small urea sensors. The CLCsolid-IPN-KOH balls, when swollen, can be used to detect divalent metal ions, making these photonic balls a potential new sensor platform with simple functionalization and minimal sample requirements.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Article
Chemistry, Applied
Peiyu Tan, Feifei Lu, Yuge Han
Summary: A dual-layer structure combining the properties of two polymers is demonstrated to be efficient in strengthening the mid-to-far infrared modulation. The optimal polymerization charge for achieving the highest reflectance variation is inconsistent between the mid-wavelength and long-wavelength bands in single-layer devices. However, by adjusting the deposition sequence and thickness, a bilayer film with high reflectance contrast in different wavelength bands is obtained.
Article
Engineering, Electrical & Electronic
Qian Yang, Zhiyong Yang, Yi-Fen Lan, Shin-Tson Wu
Summary: In this study, a model based on diffraction theory and human eye's angular resolution is proposed to quantitatively evaluate the diffraction effect of transparent displays, and several factors for minimizing the diffraction effect are analyzed. By optimizing the pixel structures, it is possible to achieve diffraction-less high resolution and low aperture ratio transparent displays.
JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY
(2022)
Article
Optics
Jianghao Xiong, Qian Yang, Yannanqi Li, Shin-Tson Wu
Summary: This article proposes a new method for manufacturing liquid crystal polarization optics based on holographic imprinting. By replicating the polarization patterns of reflective liquid crystal holograms, high-quality polarization patterns can be generated. This method has widespread impact on the fabrication of liquid crystal polarization optics for advanced display and imaging systems.
LIGHT-SCIENCE & APPLICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Zhenyi Luo, Yuqiang Ding, Yi Rao, Shin-Tson Wu
Summary: The pancake lens structure offers a compact solution for near-eye displays, but the use of a half mirror results in a significant optical loss. The proposed folded optical structure, using polarization-selective cholesteric liquid crystal reflectors, doubles the efficiency and optical path length to balance the tradeoff between form factor and efficiency. Simulation results match well with experiments. Two display configurations are established to evaluate the imaging performances of the proposed pancake lens structure.
JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY
(2023)
Article
Engineering, Electrical & Electronic
Yizhou Qian, Zhiyong Yang, Yu-Hsin Huang, Kuan-Heng Lin, Shin-Tson Wu
Summary: The RGB nanowire light-emitting diode (LED) structures were optimized using a 3D dipole cloud model to achieve a narrower radiation pattern, reduced angular color shift, and higher optical efficiency. Compared to micro-LEDs, which have externally quantum efficiency depending on mesa size, the RGB nanowire LEDs are more efficient for chip sizes below 20, 80, and 10 μm, respectively. Therefore, nanowire LEDs show promise for augmented reality and virtual reality displays that require high-resolution density and efficient directional light emission.
JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY
(2023)
Article
Engineering, Electrical & Electronic
Yannanqi Li, John Semmen, Qian Yang, Shin-Tson Wu
Summary: A new electrically driven polymer-stabilized polarization volume grating (PVG) has been developed, with the diffraction efficiency modulated by a vertical electric field. By doping a small amount of liquid crystal monomer into the host cholesteric liquid crystal, a stabilized polymer network is formed, allowing for reversible unwinding. The fabricated device exhibits submillisecond response time, a large range of diffraction efficiency modulation, and clear see-through capability. Demonstrations of potential applications show suppressed rainbow effect, enhanced light efficiency, and expanded field of view for a waveguide-based augmented reality display. The unique properties and benefits of switchable PVGs could revolutionize near-eye display research, particularly in novel optical systems for augmented reality waveguide displays.
JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY
(2023)
Article
Engineering, Electrical & Electronic
En-Lin Hsiang, Zhiyong Yang, Shin-Tson Wu
Summary: Virtual reality (VR) devices use imaging optics to magnify microdisplay images, providing an immersive viewing experience. Microdisplays need high-resolution density and dynamic range to meet human vision system requirements. However, increasing resolution and dynamic range can reduce optical efficiency and complicate microdisplay panel fabrication. This paper analyzes image degradation in VR devices caused by both imaging optics and microdisplay, finding that imaging optics significantly impact microdisplay requirements, such as contrast ratio, local dimming zones, and resolution density. These findings help prevent excessive microdisplay design in pancake lens-based VR headsets.
JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY
(2023)
Article
Engineering, Electrical & Electronic
Yuqiang Ding, Yannanqi Li, Qian Yang, Shin-Tson Wu
Summary: This paper proposes a single full-color waveguide AR display based on reflective polarization volume gratings (PVGs) to improve stability and wearing comfort. By analyzing the optical system, we optimize a three-layer PVG as an in-coupler and derive the field of view limit. With a single-layer, thin PVG as an out-coupler, we achieve a relatively uniform exit pupil of 8 mm at the horizontal pupil expansion direction.
JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY
(2023)
Editorial Material
Optics
En-Lin Hsiang, Shin-Tson Wu
Summary: Compared to conventional bulky spectropolarimeters, computational spectropolarimeters reconstruct light-field information in a compact form factor, enabling new applications. A tunable liquid crystal metasurface can modulate the phase and spectral information of light, paving the way for developing compact and low-cost spectropolarimetric imaging devices with widespread applications.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Zhiyong Yang, Yizhou Qian, Junyu Zou, Chia-Lun Lee, Chih-Lung Lin, Shin-Tson Wu
Summary: To achieve high resolution and low power consumption in virtual reality applications, field sequential color (FSC) is used to triple the resolution density and optical efficiency of LCDs. By evaluating the physical properties of a high birefringence nematic LC mixture, a fringe-field switching (FFS) LCD was designed to exhibit fast response time for FSC operation. The FSC LCD also demonstrated wide color gamut and superior color uniformity.
APPLIED SCIENCES-BASEL
(2023)
Article
Optics
Zhenyi Luo, Yannanqi Li, John Semmen, Yi Rao, Shin-Tson Wu
Summary: This study demonstrates an achromatic diffractive liquid-crystal device to overcome the chromatic aberration issue. The proposed device consists of three stacked diffractive liquid crystal optical elements with specific spectral response and polarization selectivity. Simulation and experimental results show significant improvement in imaging performance. This technology has potential applications in virtual reality and mixed reality fields.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Crystallography
Yizhou Qian, Zhiyong Yang, En-Lin Hsiang, Qian Yang, Kevin Nilsen, Yu-Hsin Huang, Kuan-Heng Lin, Shin-Tson Wu
Summary: Vehicle displays are becoming increasingly integrated into our daily lives, requiring high-resolution density and sufficient brightness to combat intense ambient light. Infotainment displays demand over 800 nit brightness to display images clearly under direct sunlight, while head-up displays need to strike a delicate balance between resolution density, brightness, transparency, and image quality.
Article
Optics
Chien-Chung Lin, Yuh-Renn Wu, Hao-Chung Kuo, Matthew S. Wong, Steven P. Denbaars, Shuji Nakamura, Ayush Pandey, Zetian Mi, Pengfei Tian, Kazuhiro Ohkawa, Daisuke Iida, Tao Wang, Yuefei Cai, Jie Bai, Zhiyong Yang, Yizhou Qian, Shin-Tson Wu, Jung Han, Chen Chen, Zhaojun Liu, Byung-Ryool Hyun, Jae-Hyun Kim, Bongkyun Jang, Hyeon-Don Kim, Hak-Joo Lee, Ying-Tsang Liu, Yu-Hung Lai, Yun-Li Li, Wanqing Meng, Haoliang Shen, Bin Liu, Xinran Wang, Kai-ling Liang, Cheng-Jhih Luo, Yen-Hsiang Fang
Summary: Micro light-emitting diode (micro-LED) is expected to play a significant role in future smart displays, offering advantages in various applications. The article focuses on the current status, challenges, and potential advances in micro-LED technology, highlighting the importance of epitaxy innovation and quantum scale structures. Peripheral components and technologies, such as microchip transfer and repair, heterogeneous integration, and novel 2D materials, are also discussed. The potential of micro-LED displays in augmented reality (AR) and the efforts to address existing problems are emphasized.
JOURNAL OF PHYSICS-PHOTONICS
(2023)
Article
Optics
Jianghao Xiong, Haizheng Zhong, Dewen Cheng, Shin-Tson Wu, Yongtian Wang
Summary: This study demonstrates a polarization hologram with full DoF for local manipulation of optical structure, based on emerging self-assembled photo-aligned liquid crystal technology. The ability to record arbitrary wavefront and perform local liquid crystal adjustment is achieved through freeform surface exposure and inkjet printing, respectively, resulting in a full-color retinal scanning display without color crosstalk.
Review
Optics
Yuqian Ding, Qian Yang, Yannanqi Li, Zhiyong Yang, Zhengyang Wang, Haowen Liang, Shin-Tson Wu
Summary: This review paper focuses on the perspectives and challenges of optical waveguide combiners for augmented reality (AR) displays. It introduces the basic device structures and operation principles of different AR architectures, and delves into different waveguide combiners, including geometric and diffractive waveguide combiners. Commonly used in-couplers and out-couplers are discussed, and their properties are analyzed in detail. The paper also explores recent advances in waveguide combiner design and modeling, and discusses the bottlenecks and future development trends in waveguide combiner technologies.
Article
Crystallography
Yuge Huang, Shin-Tson Wu
Summary: The Mini-LED backlit LCD exhibits premium display performance, including motion blur reduction, high dynamic range, and suppression of the halo effect.
LIQUID CRYSTALS TODAY
(2023)
