Article
Engineering, Electrical & Electronic
Ayesha Mohanty, Om Prakash Acharya, Bhargav Appasani, S. K. Mohapatra, Mohammad S. Khan
Summary: This paper presents and evaluates a new terahertz metamaterial absorber (MMA) for sensing applications, which offers high sensitivity and good detection performance for changes in refractive index of the environment.
IEEE SENSORS JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Yanan Jiao, Jing Lou, Zhaofu Ma, Longqing Cong, Xing Xu, Bin Zhang, Dingchang Li, Ying Yu, Wen Sun, Yang Yan, Shidong Hu, Boyan Liu, Yindong Huang, Lang Sun, Ride Wang, Ranjan Singh, Yuancheng Fan, Chao Chang, Xiaohui Du
Summary: This study demonstrates ultrafast switchable sensing functions using phototunable silicon-based terahertz metasurfaces, which show highly sensitive responses to tiny analytes and can successfully identify colorectal cells in different states.
MATERIALS HORIZONS
(2022)
Article
Physics, Multidisciplinary
Hailin Ren, Shijun Ji, Ji Zhao, Handa Dai
Summary: A plasmon-induced terahertz metamaterial absorber is introduced, using a gold bottom layer to block the transmission of terahertz waves, with a topas layer separating the pattern layer and ground layer. The absorber exhibits a 90% absorption bandwidth frequency range of 4.6-7.7 THz, with an average absorption rate of 97.6% in this range. It has polarization insensitivity due to its geometric symmetry, and can maintain over 80% absorption even at an incidence angle of 60 degrees. The absorber also shows good linear frequency shift with refractive index change, with a sensitivity of 1100 GHz per refractive index unit (GHz/RIU), making it suitable for complex electromagnetic scenarios or as a sensing element.
Article
Materials Science, Multidisciplinary
Giuseppe Emanuele Lio, Antonio Ferraro, Rafal Kowerdziej, Alexander O. Govorov, Zhiming Wang, Roberto Caputo
Summary: The researchers report the design of a metamaterial-based sensor capable of detecting small amounts of molecules in a medium. By accurately selecting the parameters of the metamaterial, a highly sensitive sensor was developed. This work paves the way for the development of novel devices for biomedical and environmental applications.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Aruna Veeraselvam, Gulam Nabi Alsath Mohammed, Kirubaveni Savarimuthu
Summary: This study presents a highly sensitive THz sensor for detecting biological samples, with a small footprint and high sensitivity. The sensor's sensitivity was estimated using absorption characteristics, and it was evaluated for various materials and biomedical samples, showing an average sensitivity of 1936 GHz/RIU.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Multidisciplinary Sciences
Myunghwan Kim, Seong-Han Kim, Chul Kang, Soeun Kim, Chul-Sik Kee
Summary: Graphene-based optical modulators have been widely studied, but weak graphene-light interactions limit the achievement of high modulation depth with low energy consumption. In this study, a high-performance graphene-based optical modulator, consisting of a photonic crystal structure and a waveguide, is proposed. It exhibits an electromagnetically-induced-transparency-like transmission spectrum at terahertz frequency, enhancing light-graphene interaction. The designed modulator achieves a high modulation depth of 98% with a small Fermi level shift of 0.05 eV, making it suitable for low power consumption in active optical devices.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Multidisciplinary
Jitong Zhong, Xiaocan Xu, Yu-Sheng Lin
Summary: The MEMS-based tunable terahertz metamaterial (TTM) exhibits tunable characteristics in resonance, polarization-dependent, and electromagnetically induced transparency (EIT) due to the configuration of eSRR. It shows potential application in refraction index sensors with good sensing performances.
Article
Optics
Dejun Liu, Xi Yu, Feng Wu, Weijie Du, Lin Chen, Feng Liu, Makoto Kuwahara, Shingo Ono
Summary: This experiment successfully demonstrates THz sensors based on asymmetric metallic hole arrays (AMHAs) that have both high-quality factor and polarization-independent characteristics. By introducing quasi-bound states in the continuum (BICs) with a quality factor exceeding 2000, the sensors exhibit enhanced sensitivity for thin membranes. The results show a frequency shift of 97.5 GHz for a 25-μm thick polyimide (PI), corresponding to a sensitivity of 147.7 GHz/RIU. The sensing performance is strongly related to the enhanced field generated by the sharp quasi-BICs. The proposed sensor has great potential for real-time chemical and biomolecular sensing applications.
Article
Optics
Reena Reena, Yogita Kalra, Ajeet Kumar
Summary: This paper reports the phenomena of electromagnetically induced transparency in a metal-dielectric structure, providing a platform for high-quality factor Fano resonance in the terahertz region. By utilizing electric and magnetic dipoles in the metal and dielectric components, two resonance dips with high-quality factors were achieved, showing potential for the design and development of metamaterial-based sensing devices and biosensors.
Review
Computer Science, Information Systems
Tiziana Mancini, Augusto Marcelli, Stefano Lupi, Annalisa D'Arco
Summary: The recent pandemic has raised the need for deployable tools for rapid and effective viral detection on a large scale. Traditional techniques have limitations in sensitivity, safety, laboriousness, and long-term data analysis. Terahertz-based technologies have emerged as a new approach for high-sensitivity viral detection. In this article, we summarize the emerging THz radiation technology and its solutions and applications.
Article
Chemistry, Physical
Alin Gheorghita Mazare, Yadgar Abdulkarim, Ayoub Sabir Karim, Mehmet Bakir, Mohamed Taouzari, Fahmi F. Muhammadsharif, Bhargav Appasani, Olcay Altintas, Muharrem Karaaslan, Nicu Bizon
Summary: In this study, a triple band perfect metamaterial absorber based on Pythagorean fractal geometry was proposed and analyzed for terahertz sensing applications. The design exhibited enhanced sensing performance and achieved three intensive absorption peaks within the desired frequency range. The proposed design was found to be sensitive to changes in substrate type, resonator material, substrate thickness, and refractive index of the surrounding medium. The metamaterial sensor demonstrated high sensitivity to variations in thickness at a fixed analyte refractive index, making it suitable for biomedical applications.
Article
Physics, Multidisciplinary
Nengxun Yang, Yixuan Wang, Lingqiao Li, Yang Ren, Zhihui He, Wei Cui, Zhimin Yang, Shaojun Lu, Xiongxiong Wu, Lang Bai
Summary: In this paper, a multiple bulging black phosphorus (BP)-based metasurface is proposed to study its reflection responses and sensing performances. The results show that the reflection dips are caused by the coupling between dipole resonance modes and poly-poles resonance modes. Furthermore, the dipoles resonance modes and poly-poles resonance modes can mutually enhance and inhibit each other, and tunable reflection spectra can be achieved by symmetrically and asymmetrically adjusting the bulging of the proposed BP-based metasurface. Additionally, the reflection spectra as a function of the polarization of incident light are discussed. It is found that a dipole resonance mode on the vertical side at the direction of ZZ for BP is gradually fully excited, resulting in an additional obvious reflection dip as the polarization angle theta increases from 0 degrees to 90 degrees. Particularly, the proposed BP-based metasurface demonstrates a sensing performance with the maximum sensitivity S = 1.5 mu m/RIU. The results may provide a way to design micro-nano plasmonic devices.
NEW JOURNAL OF PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Guangsheng Deng, Linying Fang, Haisheng Mo, Jun Yang, Ying Li, Zhiping Yin
Summary: This article proposes a new metamaterial absorber for liquid sensing, which demonstrates good sensitivity. The sensor structure consists of dual quartz substrates, and the enhanced spectral shift per refractive index unit is achieved by incorporating dual semitoroidal resonators. Experimental results validate the potential application of this sensor in detecting solutions with different concentrations and commonly used oils.
IEEE SENSORS JOURNAL
(2022)
Article
Physics, Applied
Yuanyuan Bai, Chunmei Ouyang, Zhibo Yao, Shilei Liu, Yanfeng Li, Liyuan Liu, Jianqiang Gu, Jiaguang Han, Weili Zhang
Summary: In this work, a metasurface with a multi-angle polarization conversion function is proposed, which consists of a top metal structure layer, a dielectric spacer, and a bottom metal film. The unit cell in the metal structure layer consists of two L-shaped elements which are symmetric about the -45 degrees axis and rotated clockwise and counterclockwise around the center, respectively. Compared with recent reports, the structure proposed here is more flexible in polarization conversion and more suitable for practical applications and has great potential in the terahertz field.
APPLIED PHYSICS LETTERS
(2023)
Article
Optics
Xingyuan Zhang, Wenqiao Shi, Jianqiang Gu, Longqing Cong, Xieyu Chen, Kemeng Wang, Quan Xu, Jiaguang Han, Weili Zhang
Summary: This study demonstrates multiple bound states in the continuum (BICs) in a terahertz metasurface consisting of metallic split ring resonators (SRRs). The evolution from BICs to quasi-BICs (QBICs) is achieved by varying the gap width of the SRRs. Experimental results show that the leakage behavior of these QBICs is strongly influenced by the intrinsic Ohmic loss in the SRRs, while it is robust to tilted incidence.
Article
Materials Science, Multidisciplinary
Xi Feng, Xieyu Chen, Yongchang Lu, Qingwei Wang, Li Niu, Quan Xu, Xueqian Zhang, Jiaguang Han, Weili Zhang
Summary: This paper proposes and experimentally demonstrates a new method for directly emitting focused THz vortex beams with desired orbital angular momentums. The method utilizes patterned ITO film to generate nonlinear THz emission, achieving effective integration of THz emission and vortex-beam generation.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Optics
Xiaolin Zhuang, Wei Zhang, Kemeng Wang, Yangfan Gu, Youwen An, Xueqian Zhang, Jianqiang Gu, Dan Luo, Jiaguang Han, Weili Zhang
Summary: A C-shape-split-ring-based phase discontinuity metasurface with a liquid crystal elastomer substrate is introduced for infrared modulation of terahertz wavefront. By manipulating the deflection of the substrate, controllable and broadband wavefront steering is achieved, with a maximum output angle change of 22 degrees at 0.68 THz. The liquid crystal elastomer metasurface also demonstrates the performance of a beam steerer, frequency modulator, and tunable beam splitter, which are highly desired in terahertz wireless communication and imaging systems.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Optics
Fan Huang, Quan Xu, Wanying Liu, Tong Wu, Jianqiang Gu, Jiaguang Han, Weili Zhang
Summary: A method for generating superposed optical vortices in the terahertz frequency range with orthogonal circular polarization incidences is proposed and demonstrated. This method provides opportunities for developing ultracompact terahertz functional devices.
PHOTONICS RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Qingwei Wang, Xueqian Zhang, Quan Xu, Xi Feng, Yongchang Lu, Li Niu, Xieyu Chen, Eric Plum, Jianqiang Gu, Quanlong Yang, Ming Fang, Zhixiang Huang, Shuang Zhang, Jiaguang Han, Weili Zhang
Summary: Coupling between different meta-atoms within the unit-cell can be used to control nonlinear THz generation, where achiral coupling provides control over THz field amplitude and chiral coupling makes THz generation sensitive to pump polarization. Multiplexed pump-handedness-selective nonlinear metasurfaces can be realized, allowing for the generation of THz beams with different orbital angular momentum. This approach enables the development of various integrated nonlinear THz devices.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yi Xu, Jianqiang Gu, Yufei Gao, Quanlong Yang, Wanying Liu, Zhibo Yao, Quan Xu, Jiaguang Han, Weili Zhang
Summary: This study presents a novel meta-atom scheme using a silicon-silica-silicon sandwich-shaped structure, which enlarges the propagation phase and improves the dispersion engineering capability at low losses. An achromatic metalens is constructed using these meta-atoms, which exhibits remarkable achromatic focusing performance in the THz domain. This research not only demonstrates an outstanding terahertz achromatic metalens but also provides innovative ideas for constructing achromatic metasurfaces in various applications, beyond the THz domain.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Physics, Applied
Jiajun Ma, Chunmei Ouyang, Yuting Yang, Hongyi Li, Li Niu, Xinyue Qian, Yi Liu, Bin Yang, Quan Xu, Yanfeng Li, Liyuan Liu, Zhen Tian, Jianqiang Gu, Jiaguang Han, Weili Zhang
Summary: Topological photonics has advanced from theoretical concept to practical applications, with valley topological photonic crystals being a key candidate for future functional devices. However, the design and arrangement limitations have hindered the exploration of multichannel valley topological beam splitters. In this study, we investigate and demonstrate the robustness of different domain walls in valley topological photonic crystals and present a highly integrated multichannel valley topological beam splitter. Compared to traditional beam splitters, it is more robust, compact, and offers higher integration and more output ports. This brings new opportunities for engineering the flow of light and designing miniaturized integrated photonic devices.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Guanxuan Guo, Xueqian Zhang, Li Niu, Tong Wu, Xieyu Chen, Quan Xu, Jiaguang Han, Weili Zhang
Summary: We propose a programmable graphene metasurface based on the quantum effect analogue, electromagnetically induced transparency, which enables continuous amplitude and phase tuning of cross-polarized transmission in the terahertz (THz) regime. This programmable scheme allows flexible control over the diffraction angles and focal lengths of the transmitted THz beams, providing new inspirations for THz programmable metasurface devices.
Article
Chemistry, Physical
Jiaqi Zhang, Yuyue Yan, Hongwei Zhao, Xudong Niu, Liyuan Liu, Chunmei Ouyang, Weili Zhang
Summary: The GHz and THz complex dielectric spectra of a polyethylene glycol dimethyl ether (2000 g/mol) aqueous solution were investigated. The reorientation relaxation of water in this type of macro-amphiphilic molecule solution can be well described by three Debye models: under-coordinated water, bulk-like water, and slow hydrating water. The reorientation relaxation timescales of bulk-like water and slow hydration water both increase with concentration. By calculating the experimental Kirkwood factors of bulk-like and slow hydrating water, the changes in their dipole moments were estimated. The estimated water molecule numbers of three water components around monomers also support the sorting of water components.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Optics
Xiaohan Jiang, Quan Xu, Yuanhao Lang, Wanying Liu, Xieyu Chen, Yuehong Xu, Hang Ren, Xibin Wang, Su Xu, Xueqian Zhang, Chunmei Ouyang, Zhen Tian, Jianqiang Gu, Jiaguang Han, Weili Zhang
Summary: Geometric phase metasurfaces, a branch of meta-optics, have gained significant attention in recent years. The concept has been extended to near-field regime for the control of surface plasmons (SPs) by rotating dipole sources. However, there are still puzzles and shortcomings, such as the explanation for the reported geometric phases equal to the rotation angle and twice the rotation angle of the dipole sources for SP controls, and the limited control strategies for a single wavelength. In this study, a rigorous derivation of SP excitation by circularly polarized illumination is performed, clarifying the rotation dependence and coordinate correlation of geometric phase control of SPs. Furthermore, a holographic approach is proposed to implement multiplexed geometric phase control, demonstrating the ability to couple and steer incident circular polarizations of different wavelengths and spin directions to specific SP focusing beams. This work paves the way for integrated and multiplexed SP devices.
LASER & PHOTONICS REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Patinharekandy Prabhathan, Kandammathe Valiyaveedu Sreekanth, Jinghua Teng, Ranjan Singh
Summary: This study proposes a novel approach to chalcogenide phase change material (PCM)-incorporated steganographic nano-optical coatings (SNOC) for optical steganography. The SNOC design combines a broad-band and a narrow-band absorber made up of PCMs to achieve tunable optical Fano resonance in the visible wavelength, which is a scalable platform for accessing the full-color range. The study demonstrates the dynamic tuning of the Fano resonance line width by switching the structural phase of PCM, providing high-purity colors. For steganography applications, the SNOC cavity layer is divided into an ultralow loss PCM and a high index dielectric material with identical optical thickness, enabling the fabrication of electrically tunable color pixels on a microheater device.
Article
Multidisciplinary Sciences
Wenhao Wang, Yogesh Kumar Srivastava, Thomas CaiWei Tan, Zhiming Wang, Ranjan Singh
Summary: Non-radiative bound states in the continuum (BICs) can create resonant cavities with confined electromagnetic energy and high-quality (Q) factors. By folding all guided modes into the light cone through periodic perturbation, BZF-BICs with ultrahigh Q factors can be achieved in a large, tunable momentum space. Unlike conventional BICs, BZF-BICs show perturbation-dependent dramatic enhancement of the Q factor throughout the momentum space and are robust against structural disorders.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Applied
Nikhil Navaratna, Yi Ji Tan, Abhishek Kumar, Manoj Gupta, Ranjan Singh
Summary: On-chip terahertz (THz) biosensors have potential for real-time, label-free, and noninvasive detection of proteins, DNA, and cancerous tissue. However, high absorption of THz waves by water necessitates evanescent field-based biosensing. A topological waveguide cavity system with topologically protected propagating interfacial modes is shown to enhance on-chip THz biosensing by accurately detecting minute frequency shifts over extended periods, facilitating real-time sensing and monitoring of biological matter.
APPLIED PHYSICS LETTERS
(2023)
Article
Multidisciplinary Sciences
Kandammathe Valiyaveedu Sreekanth, Jayakumar Perumal, U. S. Dinish, Patinharekandy Prabhathan, Yuanda Liu, Ranjan Singh, Malini Olivo, Jinghua Teng
Summary: The researchers present a scalable Tamm plasmon cavity using phase change material with large resonance tunability and demonstrated tunable SERS by matching the plasmonic resonance with the molecule absorption for sensitivity enhanced biosensing.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Ridong Jia, Sonu Kumar, Thomas Caiwei Tan, Abhishek Kumar, Yi Ji Tan, Manoj Gupta, Pascal Szriftgiser, Arokiaswami Alphones, Guillaume Ducournau, Ranjan Singh
Summary: This research presents a 100-Gbps topological wireless communication link using integrated photonic devices, addressing the challenge of momentum mismatch and achieving high gain and wide bandwidth. The valley-conserved silicon topological waveguide antenna enables active beam steering and represents a major milestone in the field of hybrid electronic-photonic-based topological wireless communications.
Article
Materials Science, Multidisciplinary
Min Zhang, Shoujun Zhang, Qingwei Wang, Yihan Xu, Liwen Jiang, Yuyue Yan, Jiao Li, Zhen Tian, Weili Zhang
Summary: An ultrathin, flexible terahertz metamaterial based on biogel has been developed to detect the transmission of terahertz waves through biomolecules in aqueous solutions. The metamaterial can detect glucose in water, human serum, and human sweat with high sensitivity and can be used for long-term management of diabetes as a wearable device.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
