Article
Chemistry, Physical
Jin Zhang, Zhenfei Li, Linda Shao, Fajun Xiao, Weiren Zhu
Summary: The study demonstrates the active modulation of EIT analog by integrating graphene into a microwave metamaterial for the first time, showing that the EIT peak can be dynamically controlled under a relatively low bias voltage applied on graphene. The continuous tuning of the EIT resonance strength is achieved by variably dampening the dark resonator using graphene.
Article
Chemistry, Multidisciplinary
Liang Gao, Chao Feng, Yongfu Li, Xiaohan Chen, Qingpu Wang, Xian Zhao
Summary: This paper investigates a metal-graphene metamaterial device that exhibits a tunable, electromagnetically induced transparency (EIT) spectral response at terahertz frequencies. The device structure, composed of a strip and a ring resonator, induces the EIT effect by serving as the bright and dark mode, respectively. By utilizing the variable conductivity of graphene to dampen the dark resonator, the device can dynamically shift its response frequency over 100 GHz, satisfying the requirement for convenient post-fabrication tunability. The proposed device also exhibits slow-light behavior with a maximum group delay of 1.2 ps. Moreover, the sensing performance is studied, showing a sensitivity of up to 100 GHz/(RIU) and a figure of merit (FOM) value exceeding 4 RIU-1. Therefore, the graphene-based metamaterial provides a new miniaturized platform to facilitate the development of terahertz modulators, sensors, and slow-light applications.
Article
Physics, Condensed Matter
Hanqing Dong, Chengjing Gao, Li Zeng, Dan Zhang, Haifeng Zhang
Summary: This study proposes an electromagnetically induced transparency (EIT) metamaterial based on the bright-dark-quasi-dark theory, which achieves the transition from EIT to electromagnetically induced absorption (EIA) by adjusting the coupling distance. By adding nested split-ring resonators (SRRs), substantial absorption enhancement is achieved, and the structure also exhibits polarization-insensitive characteristics. The influences of different structural parameters on absorption performance are further discussed.
PHYSICA B-CONDENSED MATTER
(2022)
Article
Engineering, Electrical & Electronic
Mingming Chen, Zhongyin Xiao, Fei Lv, Zhentao Cui, Qidi Xu
Summary: A simple and multi-layer metamaterial made of graphene is proposed to achieve excellent manipulation of the EIT-like effect. By adjusting the Fermi level of graphene, tunable EIT-like effect can be obtained. In addition, wideband EIT-like effect with high transmission can be achieved by adjusting the geometrical parameters of the metamaterial.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Tingting Lang, Zhenyu Yu, Jinhui Zhang, Zhi Hong, Jianjun Liu, Ping Wang
Summary: This study designs and theoretically analyzes a new type of sensor based on electromagnetically induced transparency metamaterials. The proposed metamaterial sensor consists of a polyimide substrate at the bottom and a periodic aluminum structure on the top. CST STUDIO SUITE is used to determine the transmission spectrum of the metamaterials in the terahertz band. The simulation results show that the sensitivity of the metamaterial sensor reaches 270.4 GHz/RIU. The metamaterial sensor is then fabricated to detect bovine serum albumin with a sensitivity of 15.390 GHz/(mg/mL) and a limit of detection (LOD) of 8.97 μg/mL in the concentration range of 0-10 mg/mL. The proposed sensor has the advantages of incident-angle insensitivity, polarization insensitivity, and small size, making it suitable for various research fields including physics, biology, and chemical sensing.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Optics
Tiantian Zheng, Zhongyin Xiao, Mingming Chen, Xiaoyu Wang, Xiang Miao
Summary: This paper proposes a new structure that generates broadband electromagnetically induced transparency (EIT) through destructive interference. The bandwidth of the EIT effect is expanded by introducing a hybridization bandgap. The structure has rotational symmetry and is insensitive to polarization angle.
OPTICS COMMUNICATIONS
(2022)
Article
Nanoscience & Nanotechnology
Yuze Hu, Mingyu Tong, Siyang Hu, Weibao He, Xiang'ai Cheng, Tian Jiang
Summary: The study presents a dual-optically tunable metaphotonic device for ultrafast terahertz switching. It achieves picosecond ultrafast photoswitching with 100% modulation depth at either 0.55 THz or 0.86 THz, controlled by continuous wave light and femtosecond laser pulse. The technology enables frequency-selective, temporally tunable, and multidimensionally-driven features, making it valuable for advanced multiplexing of information and wireless communication.
Article
Optics
Tingling Lin, Yi Huang, Shuncong Zhong, Yujie Zhong, Zhenghao Zhang, Qiuming Zeng, Yingjie Yu, Zhike Peng
Summary: THz metamaterial sensing is an emerging technology in biomedical sciences with unique characteristics. This study reports an innovative method of manipulating the electric field to enhance liquid sensing at THz frequencies, which holds bright promises for real-time monitoring of trace biomolecules.
OPTICS AND LASERS IN ENGINEERING
(2022)
Review
Engineering, Electrical & Electronic
Zhixia Xu, Yi Wang, Siyuan Liu, Jitong Ma, Shaojun Fang, Haotian Wu
Summary: Electromagnetically induced transparency (EIT) originates from destructive interference between quantum states of atoms and molecules, resulting in a narrow transparent peak in the opaque band. This phenomenon can also be achieved in classical systems, known as analogs of EIT, which exhibit high-quality resonant peaks with potential applications in highly sensitive sensors. This article provides a brief review of EIT-like metamaterials, including mathematical formulation, specific designs and applications, dynamic modulations, and future research directions.
IEEE SENSORS JOURNAL
(2023)
Article
Chemistry, Physical
Mingming Chen, Xue-Xia Yang
Summary: This work reveals the law of frequency shift in tunable EIT-like metamaterials and proposes two simple structured metamaterials for verification. The transmission amplitude and frequency of EIT-like effect can be dynamically controlled by tuning the Fermi level of graphene.
Article
Chemistry, Physical
Tiantian Zheng, Zhongyin Xiao, Mingming Chen, Xiang Miao, Xiaoyu Wang
Summary: This paper proposes a structure composed of a horizontal metal strip resonator and four C-shaped ring resonators to achieve a broadband electromagnetic induction transparency effect. By studying bright and dark modes, the three-level Lambda-type system, and electric field, the mechanism of the EIT-like effect is explained. Furthermore, a transparency window with a relative bandwidth of 91.93% is observed by reducing the distance between the SR and CRRs, showing potential applications in slow light, filters, and non-linear optics.
Article
Engineering, Electrical & Electronic
Song Wang, Shuang Wang, Xiaoli Zhao, Jianyu Zhu, Quan Li, Tai Chen
Summary: The study introduces and fabricates J-shaped planar structure metasurfaces to achieve dual-frequency toroidal dipole resonances and electromagnetically induced transparency effect in the terahertz band. By coupling two asymmetric J-shaped metal rings, low-frequency and high-frequency toroidal dipole resonances are simultaneously excited, creating a transparent window. The resonant response of the toroidal dipole can be adjusted by structural parameters, showing sensing characteristics of the metasurfaces, providing potential for the development of terahertz functional devices.
JOURNAL OF INFRARED MILLIMETER AND TERAHERTZ WAVES
(2021)
Article
Physics, Multidisciplinary
Tingling Lin, Yi Huang, Shuncong Zhong, Manting Luo, Yujie Zhong, Yingjie Yu, Jian Ding
Summary: The research proposed a metamaterial sensor utilizing electromagnetically induced transparency resonance, which enhances the interaction between light and matter through substrate etching, leading to significantly improved sensitivity and potential applications in biosensing.
FRONTIERS IN PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Yuze Hu, Mingyu Tong, Zhongjie Xu, Xiangai Cheng, Tian Jiang
Summary: The tunable metamaterials/metasurfaces have enabled novel optical components and led to breakthroughs in light tailoring with diverse spatiotemporal dynamics. By exploring the incident angle-induced symmetry breaking, the study demonstrates versatile and ultrafast THz switching behaviors, providing a crucial pathway for multidimensional THz wave manipulation.
Article
Engineering, Electrical & Electronic
Renxia Ning, Zhiqiang Xiao, Zhenhai Chen, Wei Huang
Summary: This study investigates a multilayer structure of graphene with nesting vanadium dioxide (VO2) that exhibits a dual-tunable electromagnetically induced transparency (EIT) effect. The EIT effect can be tuned based on the chemical potential of graphene and temperature of VO2, and is found to be insensitive to polarization. The results have potential applications in terahertz devices.
JOURNAL OF ELECTRONIC MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Yi Lei, Jingjing Zhang, Jia Wei Wang, Xinxin Gao, Tie Jun Cui
Summary: A miniaturized spoof plasmonic isolator, consisting of a deep-subwavelength spoof localized surface plasmon (SLSP) resonator and an ultrathin spoof surface plasmon polariton waveguide, is proposed and experimentally demonstrated. The isolation property is enhanced by coating the SLSP resonator with a magneto-optical material, enabling multifrequency isolation that can be dynamically controlled by changing the biased magnetic field intensity. This design scheme is further extended to realize a four-port circulator, allowing for one-way transmission in opposite directions in two separate frequency bands. The proposed devices have potential for nonreciprocal applications in microwave communication systems.
ADVANCED MATERIALS TECHNOLOGIES
(2022)
Article
Optics
Fengwen Kang, Yongping Du, Ze Yang, Philippe Boutinaud, Martijn Wubs, Jie Xu, Haiyan Ou, Dongzhe Li, Kaibo Zheng, Abebe T. Tarekegne, Guohuan Sun, Xuhui Xu, Sanshui Xiao
Summary: In this study, CsPbBr3:Ln(3+) nanocrystals grown into glass were successfully designed and fabricated using an in situ nanocrystallization method. It was found that substitution of Pb2+ sites with Ln(3+) ions led to a blueshift of emission position. The nanocrystals exhibited excellent photoluminescent properties and showed good stability in various environments. Additionally, the emission intensity could be controlled through heat-cooling experiments and laser irradiation. Furthermore, a white light-emitting prototype was achieved by combining the CsPbBr3 nanocrystals with other phosphors.
LASER & PHOTONICS REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Sergii Morozov, Stefano Vezzoli, Alina Myslovska, Alessio Di Giacomo, N. Asger Mortensen, Iwan Moreels, Riccardo Sapienza
Summary: Giant shell CdSe/CdS quantum dots exhibit high brightness and flexibility, with near-unity quantum yield and suppressed blinking. However, their single photon purity is reduced due to efficient multiexcitonic emission. In this study, we observed a significant blueshift in the photoluminescence biexciton spectrum of pure-phase wurtzite quantum dots. By using spectral filtering, we achieved a 2.3 times reduction in biexciton quantum yield while preserving 60% of the exciton single photon emission, leading to an improvement in purity from g2(0)=0.07±0.01 to g2(0)=0.03±0.01. Furthermore, at higher pump fluence, the spectral purification was even more effective, resulting in up to a 6.6 times reduction in g2(0) by suppressing higher order excitons and shell states with larger blueshifts.
Article
Materials Science, Multidisciplinary
Jie Xu, Yamei Luo, Sanshui Xiao, Fengwen Kang, Kosmas L. Tsakmakidis
Summary: This study proposes an all-optical digital logical system based on unidirectional modes in the microwave regime, which can achieve continuous broadband operation for basic logic gates. Utilizing the concept of negative logic, the system exhibits low-loss, broadband, and robust characteristics, and has the potential for multi-input and/or multi-output logical functionalities, making it promising for parallel computation. The numerical simulations and theoretical analyses support the feasibility of this system.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Engineering, Biomedical
Murat Serhatlioglu, Emil Alstrup Jensen, Maria Niora, Anne Todsen Hansen, Christian Friberg Nielsen, Michelle Maria Theresia Jansman, Leticia Hosta-Rigau, Morten Hanefeld Dziegiel, Kirstine Berg-Sorensen, Ian David Hickson, Anders Kristensen
Summary: A compact microfluidic flow cytometer with viscoelastic flow focusing and fiber optical interface is demonstrated. The device allows for easy operation and interchangeable capillaries to achieve single-train particle focusing for a wide range of particle sizes. The system is integrated with optical imaging and other optofluidic modalities and achieves a high throughput of 3500 events s(-1).
ADVANCED NANOBIOMED RESEARCH
(2023)
Article
Nanoscience & Nanotechnology
Rui Chen, Yi Zheng, Xingyu Huang, Qiaoling Lin, Chaochao Ye, Meng Xiong, Martijn Wubs, Yungui Ma, Minhao Pu, Sanshui Xiao
Summary: Obtaining bound states in the continuum (BICs) in photonic crystals allows for resonances with high quality factors for lasing and nonlinear applications. We design photonic-crystal BIC cavities encircled by the photonic bandgap of lateral heterostructures to confine the mode profile and suppress side leakage. Multiple bulk quantized modes are observed in both simulation and experiment, with resonance peaks depending on the illuminating position explained by mode profile distribution analysis and numerical simulations. Our findings have potential applications in mode selectivity for BIC devices and manipulation of lasing modes or radiation patterns in photonic-crystal surface-emitting lasers or nonlinear optics.
BEILSTEIN JOURNAL OF NANOTECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Alvaro Rodriguez Echarri, Fadil Iyikanat, Sergejs Boroviks, N. Asger Mortensen, Joel D. Cox, F. Javier Garcia de Abajo
Summary: The promising applications of photonics rely on the fabrication of high-quality metal thin films with controlled thickness in the range of a few nanometers. These materials exhibit highly nonlinear response to optical fields due to ultrafast electron dynamics. However, the understanding of this phenomenon on such small length scales is limited. In this study, a new mechanism controlling the nonlinear optical response of thin metallic films is revealed, which is dominated by ultrafast electronic heat transport when the film thickness is sufficiently small. By experimentally and theoretically studying electronic transport in these materials, the researchers explained the observed temporal evolution of photoluminescence in two-pulse correlation measurements. They found that ultrafast thermal dynamics plays a crucial role in determining the strength and time-dependent characteristics of the nonlinear photoluminescence signal. Their findings provide new insights into the nonlinear optical response of nanoscale materials and offer possibilities for controlling and utilizing hot carrier distributions in metallic films.
Article
Chemistry, Multidisciplinary
Yuxin Lei, Qiaoling Lin, Sanshui Xiao, Juntao Li, Hanlin Fang
Summary: This work demonstrates the generation of deep defect states in MoTe2 fewlayers via a heating process, enabling light emission in the telecommunication O-band for quantum light emission. Optical measurements reveal localized excitons and strong interaction among defects. Furthermore, the optical emission of defects depends on the thickness of the host materials. These findings offer a new route for tailoring the optical properties of two-dimensional materials in optoelectronic applications.
Article
Materials Science, Multidisciplinary
Saskia Fiedler, Sergii Morozov, Leonid Iliushyn, Sergejs Boroviks, Martin Thomaschewski, Jianfang Wang, Timothy J. Booth, Nicolas Stenger, Christian Wolff, N. Asger Mortensen
Summary: Cathodoluminescence spectroscopy combined with second-order auto-correlation measurements of g(2)(tau) allows for extensive study of the synchronization of photon emitters in low-dimensional structures. Co-existing excitons in two-dimensional transition metal dichalcogenide monolayers serve as a great source of identical photon emitters that can be simultaneously excited by an electron. In this study, we demonstrate large photon bunching with g(2)(0) up to 156 +/- 16 in a tungsten disulfide monolayer (WS2), showing a strong dependence on the electron-beam current. By carefully selecting a simple and compact geometry, such as a thin monocrystalline gold nanodisk, we achieve a record-high bunching g(2)(0) of up to 2152 +/- 236, improving the excitation synchronization and electron-emitter interaction. This approach of controlling electron excitation of excitons in a WS2 monolayer enables the synchronization of photon emitters in an ensemble, which is crucial for advancing light information and computing technologies.
Article
Chemistry, Multidisciplinary
Moritz Fischer, Ali Sajid, Jake Iles-Smith, Alexander Hoetger, Denys I. Miakota, Mark K. Svendsen, Christoph Kastl, Stela Canulescu, Sanshui Xiao, Martijn Wubs, Kristian S. Thygesen, Alexander W. Holleitner, Nicolas Stenger
Summary: By combining theory and experiments, we have identified three carbon-based defects as the microscopic origin of luminescent centers in hBN. We have also developed a method to calculate photoluminescence excitation (PLE) maps, which accurately describe the vibronic structure of the optical transition and the phonon-assisted excitation mechanism.
Article
Nanoscience & Nanotechnology
Saskia Fiedler, Sergii Morozov, Danylo Komisar, Evgeny A. A. Ekimov, Liudmila F. F. Kulikova, Valery A. A. Davydov, Viatcheslav N. N. Agafonov, Shailesh Kumar, Christian Wolff, Sergey I. I. Bozhevolnyi, N. Asger Mortensen
Summary: Impurity-vacancy centers in diamond provide a class of robust photon sources with versatile quantum properties. The ensembles of color centers have tunable photon-emission statistics and their emission properties can be controlled by different types of excitation. Electron-beam excitation can synchronize the emitters' excitation and control the second-order correlation function g(2)(0), as confirmed by experimental results in this letter. Such a photon source based on an ensemble of few color centers in a diamond crystal offers a highly tunable platform for room temperature informational technologies.
Article
Optics
Christos Tserkezis, Christian Wolff, Fedor A. Shuklin, Francesco Todisco, Mikkel H. Eriksen, P. A. D. Goncalves, N. Asger Mortensen
Summary: We propose an efficient approach for actively controlling the Rabi oscillations in nanophotonic emitter-cavity analogs based on the presence of an element with optical gain. Inspired by recent developments in parity-time (PT)-symmetry photonics, we show that nano-or microcavities where intrinsic losses are partially or fully compensated by an externally controllable amount of gain offer unique capabilities for manipulating the dynamics of extended (collective) excitonic emitter systems. Furthermore, we show that there is a specific gain value that leads to an exceptional point, where both the emitter and cavity occupation oscillate practically in phase, with occupation numbers that can significantly exceed unity.
Article
Materials Science, Multidisciplinary
Gino Wegner, Dan-Nha Huynh, N. Asger Mortensen, Francesco Intravaia, Kurt Busch
Summary: The paper discusses the impact of an extended model proposed by Halevi on the nonlocal response of plasmonic materials and nanostructures. It reevaluates the Mie scattering coefficients for a cylinder and corresponding plasmon-polariton resonances within this framework. The analysis reveals a nonlocal, collisional, and size-dependent damping term that affects the resonances in the extinction spectrum. The implementation of the Halevi model in the time domain is particularly important for efficient and accurate modeling of nanogap structures and other nanoscale features in nanoplasmonics applications.
Article
Materials Science, Multidisciplinary
Emil Alstrup Jensen, Murat Serhatlioglu, Cihan Uyanik, Anne Todsen Hansen, Sadasivan Puthusserypady, Morten Hanefeld Dziegiel, Anders Kristensen
Summary: Label-free blood typing using Raman spectroscopy and artificial intelligence was demonstrated in this study. Training an AI model on a dataset of Raman spectra of blood samples allowed classification of ABO blood group, erythrocyte antigens, platelet antigens, antibody titers, and ABH-secretor status. The results show promising potential for future applications in transfusion medicine and blood banking.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Optics
Siqi Yan, Yan Zuo, Sanshui Xiao, Leif Katsuo Oxenlowe, Yunhong Ding
Summary: In this study, a novel double slot structure is designed by combining the silicon slot and the plasmonic slot waveguide, which improves graphene absorption and reduces metallic absorption. The demonstrated photodetector based on this structure has high responsivity and large bandwidth, providing a competitive solution for silicon photodetectors.
OPTO-ELECTRONIC ADVANCES
(2022)
