Review
Crystallography
Le Zhou, Sijie Liu
Summary: This review summarizes the structures, principles, and characteristics of several devices that have potential application in controllable anti-peeping displays. The advantages of LCs/polymer composite films, including long life, low power consumption, and energy saving, make them the mainstream technology for next-generation viewing angle-controllable displays.
Article
Optics
Esam A. A. Hagras, Mohamed Farhat O. Hameed, S. S. A. Obayya
Summary: A compact terahertz dual core photonic crystal fiber polarization splitter is presented, which utilizes a nematic liquid crystal (NLC) of type E7 to achieve high birefringence. The design uses TOPAS as the background material and investigates the impact of geometric parameters and the temperature dependence of the NLC on the splitter's performance. The numerical results show a device length of 3.848 cm with low crosstalk and a large bandwidth of 58 GHz. The design is less sensitive to fabrication perturbations and has potential for THz applications.
Article
Optics
Youan Xu, Baofu Ding, Ziyang Huang, Lixin Dai, Peng Liu, Bing Li, Wei Cai, Hui-Ming Cheng, Bilu Liu
Summary: Birefringent optical elements that work in the deep ultraviolet (DUV) region are increasingly important. However, most DUV optical elements have fixed birefringence, which is difficult to tune. In this study, a birefringence-tunable optical hydrogel with a mechano-birefringence effect in the DUV region is invented based on a two-dimensional low-cobalt-doped titanate. The hydrogel can modulate 303 nm DUV light with large phase tunability by varying the strain from 0 to 50%. This work opens the door to designing and fabricating new DUV birefringence-tunable elements using optical hydrogels responsive to mechanical stimuli.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Yi Ren, Bin Tang
Summary: This paper presents a multi-functional terahertz metamaterial device based on gold and vanadium dioxide, showcasing switchable performance between perfect absorption and broadband asymmetric transmission. The device demonstrates high efficiency in absorption and transmission, as well as perfect polarization conversion.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Masaya Masuda, Takuya Kobayashi, Michinari Kohri, Keiki Kishikawa
Summary: A new thermo-optical switching material that demonstrates birefringence inversion without changing columnar alignment by controlling temperature has been synthesized in the field of columnar liquid crystals. The mechanism involves urea molecules forming one-dimensional linear molecular aggregates, which exhibit rectangular and hexagonal columnar phases. The perfect disappearance of texture during the transition between two columnar phases is observed under polarized light optical microscopy.
Article
Chemistry, Analytical
Haoqing Jiang, Yue Wang, Zijian Cui, Xiaoju Zhang, Yongqiang Zhu, Kuang Zhang
Summary: This study proposes a switchable terahertz metamaterial device based on vanadium dioxide, which can switch between transmission and absorption modes with high transmission rate and absorption peak. The device achieves transmission and quad-band resonance absorption in the terahertz frequency range by varying the temperature of vanadium dioxide.
Article
Materials Science, Multidisciplinary
P. K. Tripathi, D. P. Singh, T. Yadav, V Singh, A. K. Srivastava, Y. S. Negi
Summary: In this study, the effect of ferric oxide nanoparticles (Fe2O3 NPs) on the birefringence and order parameter of a nematic liquid crystalline (NLC) material was investigated. The results showed that the birefringence value increased with the concentration of NPs in the NLC matrix, indicating an improved order parameter. Polarized optical microscopy confirmed the enhanced ordering of LC molecules. This study provides insights into the guest-host interactions for improved optical applications of LC materials.
Article
Materials Science, Multidisciplinary
Yuan Liu, Wei Chen, Jie Tang, Xiaoyi Xu, Peng Chen, Chao-Qun Ma, Wang Zhang, Bing-Yan Wei, Yang Ming, Guo-Xin Cui, Yong Zhang, Wei Hu, Yan-Qing Lu
Summary: The collaboration of binary mask engineered nonlinear photonic crystal and space-variant liquid-crystal geometric phase element enables the switchable generation of second-harmonic Airy beam and Airy vortex beam, achieving wavelength transformation, OAM conversion, and propagation trajectory inflection simultaneously.
ADVANCED OPTICAL MATERIALS
(2021)
Article
Optics
Ben Pelleg, Carl Steinhauser, Marquise Pullen, Joseph Linden, Adam Fontecchio
Summary: This paper presents a mechanism for spectral line emission detection based on switchable spectral filters, enabling remote sensing tasks in a broad passband while detecting emission in a particular spectral line. The concept is demonstrated through modeling a sensor with an integrated HPDLC filter and building a detection algorithm capable of detecting spectral line emission.
Article
Physics, Multidisciplinary
Saeedeh Barzegar-Parizi, Amir Ebrahimi, Kamran Ghorbani
Summary: In this paper, wideband switchable absorbers based on vanadium dioxide (VO2) have been designed and simulated at the terahertz (THz) regime. The first design achieved over 90% absorptivity in the metal state and less than 3% in the insulator state. The second design utilized a stacked structure of two VO2 layers to achieve an ultra-broadband absorption spectrum.
Article
Crystallography
Ho-Jin Sohn, Seung-Won Oh, Yeongyu Choi, Seong-Min Ji, Tae-Hoon Yoon
Summary: A simple fabrication method of a uniform-lying-helix cholesteric liquid crystal cell for phase grating device applications was demonstrated, achieving a large diffraction angle and low operating voltage by optimizing the cell gap. The diffraction efficiency of the ULH cell can be maximized with a given grating period.
Article
Chemistry, Physical
Arif Nesrullajev
Summary: This study investigates the thermo-optical properties of monomorphic smectogens, focusing on homogeneous binary mixtures of 4-n-alkyl-4'-cyanobiphenyl mesogens. It examines optical refracting and birefringent properties, as well as the behavior of the order parameter at phase transitions. Temperature dependences of refracting indices and birefringence, as well as order parameter variations during phase transitions, are analyzed.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Review
Environmental Sciences
Kaushik Pal, Alaa A. A. Aljabali, Samo Kralj, Sabu Thomas, Fernando Gomes de Souza
Summary: Combining two-dimensional graphene and its hybrid derivatives with liquid crystals, polymers, and nanomaterials enables the formation of hybrid nanocomposites with extraordinary properties, essential for switchable device technologies. Exclusive graphene self-assembly of liquid crystalline polymer nanocomposites exhibits unique functionalities, serving as both alignment and conductive layers for novel switchable device fabrication mechanism. The ultra thin-film nanocomposites based smart switchable devices show promising applications in stretchable electronics, energy storage, photodetectors, high contrast displays, and optoelectronics.
Article
Optics
Shima Rajabali, Ileana-Cristina Benea-Chelmus
Summary: Photonic integrated circuits have played a significant role in the natural sciences, but terahertz technologies have not fully utilized the design and material freedom provided by these circuits. This perspective focuses on the current state-of-the-art, challenges, and prospects of hybrid optical-terahertz photonic chips, particularly in nonlinear waveguides and waveguide-integrated photoconductive devices. The integration and miniaturization of terahertz photonics on a single chip may enable complex functionalities compatible with telecom and fiber technologies.
Article
Physics, Multidisciplinary
DaoHong Liu, ChuanYu Zhang, Zhenkun Duan
Summary: A switchable terahertz metasurface based on VO2 multilayer structure is proposed in this paper, which can achieve switchable polarization conversion and reflection phase modulation for arbitrarily polarized waves at different temperatures. Arbitrary phase regulation can be achieved by rotating the VO2 strips and altering CSRR's geometry, providing wavefront phase modulation function.
Article
Chemistry, Analytical
Fatima Taleb, Ibraheem Al-Naib, Martin Koch
Article
Crystallography
Ibraheem Al-Naib
Review
Chemistry, Multidisciplinary
Murad Althobaiti, Ibraheem Al-Naib
APPLIED SCIENCES-BASEL
(2020)
Article
Engineering, Electrical & Electronic
Ibraheem Al-Naib
Summary: This paper proposes a terahertz metasurface supercell consisting of two ring resonators with slightly different radii, which excites an electromagnetic-induced transparency (EIT)-like resonance with an ultrahigh figure of merit. The impact of the coupling between the two rings on the transmission amplitude response, quality factor, and EIT peak amplitude is investigated by varying the radius of the top resonator. The achieved figure of merit of the EIT peak reaches 88.65 and almost 20,000 when using gold and a perfect electric conductor for the metallic layer, respectively. The simplicity and unique properties of the proposed design make it an ideal candidate for filtering, slow light applications, and sensing.
JOURNAL OF INFRARED MILLIMETER AND TERAHERTZ WAVES
(2021)
Article
Chemistry, Analytical
Gameel Saleh, Ijlal Shahrukh Ateeq, Ibraheem Al-Naib
Summary: This study developed a biosensor specifically designed for sensing glucose levels in 1 μL of solution, demonstrating excellent prediction accuracy and sensitivity.
Article
Chemistry, Multidisciplinary
Thomas CaiWei Tan, Yogesh Kumar Srivastava, Rajour Tanyi Ako, Wenhao Wang, Madhu Bhaskaran, Sharath Sriram, Ibraheem Al-Naib, Eric Plum, Ranjan Singh
Summary: This research demonstrates the creation of a dynamically controllable quasi-bound state in the continuum (QBIC) with ultrahigh quality factor by embedding nanometric dielectric or semiconductor layers on a symmetric metallic metasurface at terahertz frequencies. The photoexcitation of nanostrips of germanium enables ultrafast switching of a QBIC resonance with significant transmission intensity modulation, presenting opportunities for active micro-nanophotonic devices. An optimization model is provided for (switchable) QBIC resonances in metamaterial arrays, which can serve as an enabling platform for active micro-nanophotonic devices.
ADVANCED MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
Murad Althobaiti, Ibraheem Al-Naib
Summary: This study presents an optimized dual-channel approach for non-invasive near-infrared glucose sensors, using short and long channels to measure interference noise and glucose level information separately. The findings suggest specific source-detector separation distances and wavelengths for optimal performance, potentially paving the way for wider adoption of these sensors in healthcare.
IEEE PHOTONICS JOURNAL
(2021)
Review
Chemistry, Analytical
Bushra Alsunaidi, Murad Althobaiti, Mahbubunnabi Tamal, Waleed Albaker, Ibraheem Al-Naib
Summary: The prevalence of diabetes is increasing globally, with over 690 million cases expected worldwide by 2045. Traditional glucose monitoring methods are invasive, painful, and costly, leading to a rising demand for non-invasive, painless, economical, and reliable monitoring approaches. Over the past few decades, many glucose sensing technologies have been developed and researchers have been working on improving these technologies.
Article
Crystallography
Ibraheem Al-Naib
Summary: This article discusses the use of a planar metamaterial sensor at terahertz frequencies to detect glucose concentration levels, showing the sensor's performance at different concentrations and its sensitivity to changes in concentration. The study demonstrates the potential applications of this design in diagnosing hypocalcemia and hyperglycemia cases.
Article
Computer Science, Information Systems
Ibrahim Aljamaan, Ibraheem Al-Naib
Summary: This study proposed a nonlinear system identification approach to develop a mathematical model for predicting blood glucose levels of type 1 diabetes mellitus patients. By using simulation software and MATLAB code processing, the model showed strong predictive capability in validation tests.
Article
Multidisciplinary Sciences
Latifah Almulla, Ibraheem Al-Naib, Ijlal Shahrukh Ateeq, Murad Althobaiti
Summary: This study aimed to explore the feasibility of functional near-infrared spectroscopy (fNIRS) for studying observation and motor imagination of different postural tasks. The results showed significant activation in prefrontal or motor regions during experiments combining action observation and motor imagery, while there was almost no significant increase in activations during action observation experiments. More demanding balance tasks resulted in higher activation patterns, particularly in the frontopolar area. The study also identified differences in premotor and supplementary motor cortices related to balance control. The results of this study are consistent with previous functional magnetic resonance imaging studies on this topic.
Article
Chemistry, Analytical
Ibraheem Al-Naib
Summary: In this article, a free-standing terahertz metasurface based on asymmetric S-shaped complementary resonators is presented. The metasurface features very good field confinement and has been tested as a biosensor for glucose concentration detection, showing significant resonance frequency redshifts and wavelength sensitivity. This study opens up new possibilities for future biosensor applications.
Article
Chemistry, Physical
Ibraheem Al-Naib, Ijlal Shahrukh Ateeq
Summary: In this paper, a new approach to excite sharp asymmetric resonances using a single completely symmetric split-ring resonator (SRR) inside a rectangular waveguide is proposed. The method is based on an asymmetry in the excitation of a symmetric split-ring resonator by placing it away from the center of the waveguide along its horizontal axis. In turn, a prominent asymmetric resonance was observed in the transmission amplitude of both the simulated results and the measured data. Using a single symmetric SRR with an asymmetric distance of 6 mm from the center of a rectangular waveguide led to the excitation of a sharp resonance with a Q-factor of 314 at 6.9 GHz. More importantly, a parametric study simulating different overlayer analytes with various refractive indices revealed a wavelength sensitivity of 579,710 nm/RIU for 150 mu m analyte thickness.
Review
Chemistry, Analytical
Murad Althobaiti, Sajid Ali, Nasir G. Hariri, Kamran Hameed, Yara Alagl, Najwa Alzahrani, Sara Alzahrani, Ibraheem Al-Naib
Summary: Lumbar puncture is a minimally invasive procedure for sampling cerebrospinal fluid or injecting drugs, but it carries a high risk of failure. The accurate localization of the epidural space is crucial to avoid complications. Therefore, advanced techniques for localization of the epidural space are essential, and this paper reviews the research on building sensors to guide spinal needles.
Article
Computer Science, Information Systems
Murad Althobaiti, Yara Alagl, Najwa Ali Alzahrani, Sara Alzahrani, Sajid Ali, Nasir G. Hariri, Kamran Hameed, Ibraheem Al-Naib
Summary: This article presents a high-accuracy and low-cost smart epidural needle system that utilizes force puncture sensing and guidance mechanism. The system incorporates a subminiature load cell embedded in the needle to measure the force exerted on the needle tip by each tissue layer. A classifier model was developed and tested to identify the force range for each layer, ensuring safe insertion and accurate targeting. Experimental results demonstrate an accuracy of about 86.7% in identifying the needle location, highlighting the promising outcomes and feasible solution for future development of spinal epidural needle systems.
