Article
Optics
Tao Zhou, Suguo Chen, Xiaoju Zhang, Xiang Zhang, Hui Hu, Yue Wang
Summary: In this work, a study of bright-bright mode electromagnetically induced transparency based on carbon nanotube films terahertz metasurface is presented. The formation mechanism of the transparent window is analyzed, and the sensing performance and slow light characteristics of the proposed metasurface are investigated. This study provides opportunities for electromagnetically induced transparency applications.
Article
Computer Science, Information Systems
Jingwei Wu, Meng Liu, Xueqian Zhang, Yanfeng Li, Huabin Wang, Jiaguang Han
Summary: Researchers have successfully simulated the plasmon-induced transparency effect in a waveguide system in the terahertz regime, demonstrating giant modulation of the PIT effect by inserting coupled split-ring resonator pairs into a tapered parallel plate waveguide, potentially enabling the development of novel integrated terahertz devices.
Article
Physics, Multidisciplinary
Qiuming Zeng, Yi Huang, Shuncong Zhong, Tingling Lin, Yujie Zhong, Zhenghao Zhang, Yingjie Yu, Zhike Peng
Summary: This paper proposes a bilayer metamaterial for realizing broadband transmission in a terahertz filter. The study finds that compared to traditional monolayer structures, the bilayer metamaterial can generate additional transmission peaks, and the bandwidth can be regulated by adjusting the spacing between layers. Experimental results demonstrate that this design has excellent frequency selective performance.
FRONTIERS IN PHYSICS
(2022)
Article
Optics
Mengcheng Guan, Xu Sun, Jiang Wei, Xiaodong Jia, Xiangping Cheng, Ruijian Cheng
Summary: This paper presents a metamaterial biosensor composed of dual-cut wires and quadruple split-ring resonators, achieving polarization-independent plasmon-induced transparency effects in the terahertz range. The physical mechanism of the PIT effect is investigated by analyzing the surface current distribution and electric fields. The biosensor shows good sensitivity to different analyte thicknesses and refractive indices.
Article
Optics
Hao Sun, Jie Yang, Hengzhu Liu, Dan Wu, Xin Zheng
Summary: The study presents an ultrafast process-selectable modulation of plasmon-induced transparency (PIT) effect by incorporating silicon islands into metamaterials, achieving giant modulation depths as high as 129% and 109%. Along with the significant switching of the transparent window, remarkable slow light effect occurs.
CHINESE OPTICS LETTERS
(2021)
Article
Optics
Yi Ma, Lihao Huang, Lin Chen
Summary: A Vanadium-Dioxide (VO2)-embedded metamaterial is designed to achieve amplitude modulation and on-off switch at plasmon induced transparency window. With conductivity of VO2 across the phase transition by thermal and electrical stimuli, mode switch between PIT and dipole mode can be achieved. The amplitude modulation depth and the maximum frequency width at half-maximum are 77.58% and 0.4 THz, respectively. Such VO2 embedded PIT modulator is useful for manipulating terahertz radiation in various practical applications.
OPTICS COMMUNICATIONS
(2023)
Article
Optics
Hao Sun, Jianghua Zhang, Yuhua Tang, Hengzhu Liu, Jie Yang, Xin Zheng
Summary: In this study, we investigated the active formation and modulation of dual-band plasmon-induced transparency (PIT) effect in a novel metaphotonic device operating in the terahertz regime. By utilizing a newly proposed modulating mechanism, we demonstrated the dynamic modulation of terahertz waves from individual-band into dual-band PIT effects, accompanied by a slow light effect and dual-transparent windows. Our findings highlight the potential usefulness of this metaphotonic device in optical information processing and communication.
CHINESE OPTICS LETTERS
(2022)
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
Optics
Shan Yin, Dehui Zeng, Mingkun Zhang, Xintong Shi, Yuanhao Lang, Wei Huang, Wentao Zhang, Jiaguang Han
Summary: In this paper, the distinguishable modulation of different eigenmodes by lattice mode in terahertz U-shaped metasurfaces is observed, and a remarkable suppression of high order eigenmode resonance induced by the lattice is demonstrated. By quantitatively analyzing the Q factor and loss of the resonances, it is clarified that the peculiar phenomenon of suppression originates from the phase mismatch introduced by the phase difference between neighboring structures. These results provide new insights into the phase mismatch mediated transmission amplitude of eigenmode resonance in metasurfaces and open a new path for developing terahertz multifunctional devices.
Article
Chemistry, Multidisciplinary
Ben-Xin Wang, Guiyuan Duan, Wangze Lv, Yi Tao, Han Xiong, Dong-Qin Zhang, Guofeng Yang, Fang-Zhou Shu
Summary: This study presents a simple design of a terahertz metamaterial that can achieve a triple-band electromagnetically induced transparency (EIT) effect by coupling two sub-resonators. Experimental results demonstrate the realization of three transparency peaks and explore the mechanisms behind their formation. The proposed metamaterial exhibits excellent properties such as thin size, good flexibility, simple and compact structure, and high sensing sensitivity, providing guidance for the design of multifunctional multi-band EIT metamaterials.
Article
Physics, Applied
Hong Wang, Yuting Zhang, Fangrong Hu, Mingzhu Jiang, Longhui Zhang, Wentao Zhang, Jiaguang Han
Summary: In this paper, an active dual-control electromagnetically induced transparency (EIT) analog is realized by using vanadium dioxide (VO2) metasurface on a sapphire substrate. The insulator-to-metal-transition (IMT) of VO2 can result in the reconstruction of the metasurface and control the EIT resonance when electrically stimulated. Experimental results show a modulation depth of 87.7% and a group delay of 2.7 ps at the central frequency of 0.56THz. This work paves a way for the development of THz modulators, switches, and slow light devices.
APPLIED PHYSICS LETTERS
(2023)
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
Chemistry, Physical
Qun Xie, Linhui Guo, Zexuan Zhang, Panpan Gao, Mei Wang, Feng Xia, Kun Zhang, Peng Sun, Lifeng Dong, Maojin Yun
Summary: A monolayer terahertz graphene metasurface has been designed to achieve tunable plasmon-induced transparency effect in two perpendicular polarization directions based on surface plasmon polariton resonance. By adjusting the Fermi levels of graphene, penta-frequency and dual-frequency switches can be easily implemented, with excellent performances and high sensitivity. The designed metasurface also exhibits a good slow light effect, making it potentially useful for applications in switches, sensors, and slow-light devices.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Mingming Chen, Xue-Xia Yang
Summary: A high-transmission and large group delay terahertz triple-band electromagnetically induced transparency (EIT) effect is achieved in a metal-perovskite hybrid metasurface. The results show that three transparent windows have transmission amplitudes of 0.83, 0.9, and 0.89, and maximum group delays of 7.64 ps, 4.07 ps, and 4.27 ps, respectively. By adjusting the conductivity of perovskite, the triple-band EIT effect and the slow light effect can be dynamically controlled with significant modulation depths.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Optics
Qiuming Zeng, Yi Huang, Shuncong Zhong, Tingting Shi, Jianxiong Chen, Yujie Zhong, Tingling Lin, Xuefeng Chen
Summary: This study presents an innovative method to achieve broadband filtering at terahertz frequencies by manipulating the interaction between two localized surface plasmon polariton modes using multiscale-coupled plasmonic fields. The integration of strong coupling and far-field interference expands the transmission range and enhances the capability of the double-layer metamaterial for broadband filtering.
OPTICS AND LASER TECHNOLOGY
(2024)
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
Physics, Applied
Dongxun Yang, Fumikazu Murakami, Shingo Genchi, Hidekazu Tanaka, Masayoshi Tonouchi
Summary: This study used laser-induced terahertz emission spectroscopy to investigate a VO2/Si heterojunction. It was found that the local interface potential could be rapidly estimated using this technique, and the work function of VO2 was determined to be 5.17-5.25 eV as the temperature increased from 320 to 380 K. Additionally, a significant variation in terahertz emission was observed across the metal-insulator phase transition of VO2, and the doping conditions of the Si substrate had a significant impact on the terahertz emission. These results indicate a strong correlation between terahertz emission amplitude and interface electric field, supporting the rapid estimation of the work function of VO2 using terahertz emission spectroscopy.
APPLIED PHYSICS LETTERS
(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
Optics
Ryota Ito, Hayato Sekiya, Iwao Kawayama, Michinori Honma, Masayoshi Tonouchi, Toshiaki Nose
Summary: Polarization control plays a crucial role in terahertz imaging, and liquid crystals have the potential to achieve tunable polarization control. This study fabricates a twisted nematic (TN) cell using a hydrogen-bonded liquid crystal and discusses the influence of dichroism in the terahertz region. The experimental results show that the polarization state in the Gooch-Tarry minimum condition is affected by the dichroism of the liquid crystal, and a nondichroic liquid crystal is required for complete linearly polarized output. The output intensity of the dichroic liquid crystal-TN cell changes with electrical switching or rotation of the incident terahertz wave polarization direction by 90 degrees, but these intensity variations disappear when using the nondichroic hydrogen-bonded liquid crystal.
Article
Physics, Applied
Hiroto Honda, Soshi Umeda, Kanako Shojiki, Hideto Miyake, Shuhei Ichikawa, Jun Tatebayashi, Yasufumi Fujiwara, Kazunori Serita, Hironaru Murakami, Masayoshi Tonouchi, Masahiro Uemukai, Tomoyuki Tanikawa, Ryuji Katayama
Summary: A transverse quasi-phase-matched AlN channel waveguide with vertical polarity inversion was designed and fabricated to achieve far-UV second harmonic generation via the d (33) component. The successful confirmation of UV SHG was done through ultrashort pulse laser excitation.
APPLIED PHYSICS EXPRESS
(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
Physics, Applied
Alfred Leitenstorfer, Andrey S. Moskalenko, Tobias Kampfrath, Junichiro Kono, Enrique Castro-Camus, Kun Peng, Naser Qureshi, Dmitry Turchinovich, Koichiro Tanaka, Andrea G. Markelz, Martina Havenith, Cameron Hough, Hannah J. Joyce, Willie J. Padilla, Binbin Zhou, Ki-Yong Kim, Xi-Cheng Zhang, Peter Uhd Jepsen, Sukhdeep Dhillon, Miriam Vitiello, Edmund Linfield, A. Giles Davies, Matthias C. Hoffmann, Roger Lewis, Masayoshi Tonouchi, Pernille Klarskov, Tom S. Seifert, Yaroslav A. Gerasimenko, Dragan Mihailovic, Rupert Huber, Jessica L. Boland, Oleg Mitrofanov, Paul Dean, Brian N. Ellison, Peter G. Huggard, Simon P. Rea, Christopher Walker, David T. Leisawitz, Jian Rong Gao, Chong Li, Qin Chen, Gintaras Valusis, Vincent P. Wallace, Emma Pickwell-MacPherson, Xiaobang Shang, Jeffrey Hesler, Nick Ridler, Cyril C. Renaud, Ingmar Kallfass, Tadao Nagatsuma, J. Axel Zeitler, Don Arnone, Michael B. Johnston, John Cunningham
Summary: THz radiation covers a wide spectral range and has diverse applications in various scientific disciplines. The demands for advanced THz technology in radio astronomy, weather forecasting, security imaging, telecommunications, and other fields have driven the development of related technologies. It is important to explore both the scientific and technical aspects to meet the growing needs.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Fumikazu Murakami, Kazunori Serita, Iwao Kawayama, Hironaru Murakami, Kingshuk Bandopadhyay, Andrzej Materna, Augustine M. Urbas, Dorota A. Pawlak, Masayoshi Tonouchi
Summary: In this study, the carrier dynamics in a multilayered Bi2Te3-Te eutectic composite were investigated using laser terahertz emission microscopy. The results revealed the direction of the electric field between the Bi2Te3 and Te regions, indicating the carrier types and p-n junction formed at the interface. Additionally, a strong terahertz emission with parallel polarization to the interface was observed in the Te region, which can be explained by anisotropic transport of hot photocarriers. This research contributes to the exploration of eutectic heterostructures as functional materials and offers new possibilities for advanced thermoelectric and photovoltaic devices.
Article
Physics, Applied
Tomoaki Nambu, Tomohiro Nakahara, Yuma Yasuda, Yasufumi Fujiwara, Masayoshi Tonouchi, Masahiro Uemukai, Tomoyuki Tanikawa, Ryuji Katayama
Summary: We have proposed highly efficient microcavity second harmonic generation devices, and achieved a normalized wavelength conversion efficiency of 0.15% W-1 in a designed and fabricated a-plane GaN vertical monolithic microcavity second harmonic generation device pumped with a femtosecond laser. The efficiency was comparable to theoretical estimations, indicating the possibility of realizing ultra-compact and ultra-efficient devices pumped with long-pulsed or continuous wave lasers with even more pronounced resonance enhancement.
APPLIED PHYSICS EXPRESS
(2023)
Article
Biochemical Research Methods
Keiko Kitagishi, Takayuki Kawai, Masayoshi Tonouchi, Kazunori Serita
Summary: Terahertz time-domain spectroscopy is an analysis method that provides unique information on molecular vibration and rotation. In this study, researchers combined it with capillary electrophoresis by using a localized terahertz emitter on the surface of a microtube, successfully separating and detecting several carboxylic acids.
JOURNAL OF CHROMATOGRAPHY A
(2023)
Article
Computer Science, Information Systems
Yaheng Wang, Jie Su, Taiga Fukuda, Masayoshi Tonouchi, Hironaru Murakami
Summary: This study utilized MIMO-SAR technology with FMCW millimeter-wave MIMO radar to perform 2D and 3D imaging of objects. By analyzing the IF signal generated from chirp signals, Range FFT spectra were obtained with distance and reflection intensity information. Integration of reflection intensity provided comprehensive images at different distances, and a 2D cross-sectional image achieved sub-millimeter spatial resolution inside a concealed cardboard. The system successfully reconstructed a monolayered 3D image of a clothed human body's surface and showed potential for security checks.
Article
Materials Science, Multidisciplinary
Fumikazu Murakami, Atsushi Takeo, Brandon Mitchell, Volkmar Dierolf, Yasufumi Fujiwara, Masayoshi Tonouchi
Summary: This study explores the optical and electrical properties of Eu-doped GaN superlattice structures using terahertz emission spectroscopy. The results show that Eu doping reduces the bandgap of GaN and increases its refractive index, resulting in potential barriers and carrier confinement within the superlattice structure. Temperature dependence analysis of terahertz emission confirms significant carrier confinement even in dilutely doped superlattice structures, enhancing carrier recombination in the Eu-doped regions.
COMMUNICATIONS MATERIALS
(2023)
