Article
Materials Science, Multidisciplinary
Xueqing He, Tigang Ning, Li Pei, Jingjing Zheng, Jing Li, Jianshuai Wang
Summary: In this paper, a novel graphene-dielectric hybrid plasmonic waveguide (GDHPW) is proposed, with ultra-small mode area and long propagation length achieved by tuning key structural parameters and chemical potential. Low crosstalk properties between two GDHPWs on a substrate are analyzed, and alternative modified structures with optical confinement performances are proposed, serving as fundamental building blocks for various tunable high-density integrated photonic components and devices.
RESULTS IN PHYSICS
(2021)
Article
Optics
Yindi Wang, Hongxia Liu, Shulong Wang, Ming Cai
Summary: A subwavelength electro-optic switch at 1550 nm is proposed, which utilizes bilayer graphene in a hybrid waveguide. The switch shows excellent performance with small device size and low voltage modulation requirement, making it suitable for various applications. Additionally, it has wide bandwidth, low energy consumption, and good robustness, indicating great potential for optoelectronic integrated circuits.
OPTICS COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Wenyu Zhao, Hongyuan Li, Xiao Xiao, Yue Jiang, Kenji Watanabe, Takashi Taniguchi, Alex Zettl, Feng Wang
Summary: Graphene nanoribbons with low edge roughness fabricated using dry lithography method support low-loss and tunable plasmonic waveguide modes, which were observed using cryogenic infrared nanoscopy and can be adjusted through electrostatic gating.
Article
Chemistry, Analytical
Yindi Wang, Hongxia Liu, Shulong Wang, Ming Cai
Summary: This paper presents a hybrid waveguide based on metal surface plasmon polaritons (SPPs) at 1550 nm, which achieves excellent waveguide characteristics and has great application potential in optoelectronic integrated circuits.
Article
Nanoscience & Nanotechnology
Tao Cui, Yan Shen, Ao Cheng, Runze Zhan, Zebo Zheng, Bo Tian, Jia Shi, Yanlin Ke, Lei Shao, Huanjun Chen, Shaozhi Deng
Summary: This study successfully prepared a high-quality single-crystalline Mo microrod waveguide structure and utilized subwavelength gratings to excite the surface plasmon polariton behavior of Mo. The optimized Mo microrod exhibited highly efficient waveguide performance.
Article
Chemistry, Physical
Akbar Asadi, Mohammad Reza Jafari, Mehran Shahmansouri
Summary: This paper introduces a symmetric graphene dielectric hybrid plasmonic waveguide structure with ultra-deep subwavelength confinement in the mid-infrared spectrum. By adjusting the waveguide geometry dimensions and graphene Fermi energy, excellent mode characteristics can be achieved, while the proposed structure exhibits very small crosstalk effects.
Article
Physics, Multidisciplinary
Jinwen Huang, Zhengyong Song
Summary: The terahertz waveguide modulator combining noble metal and graphene was studied, showing an increase in propagation loss with a change in Fermi level. Optimization of structure parameters led to a modulation depth of 6.1 dB μm(-1) at 5 THz. The device achieved a modulation depth of 1.5 dB μm(-1) at 10 THz while maintaining an effective mode area below 10(-5), due to the confinement of allowed mode in a small area.
Article
Crystallography
Qian Zhang, Jinbin Pan, Shulong Wang, Yongqian Du, Jieyu Wu
Summary: A triangle hybrid plasmonic waveguide is introduced, which can achieve longer propagation length and relatively deep subwavelength mode confinement. The analysis shows that this waveguide is stable and performs excellently, which is significant for manipulating light waves at sub-wavelength dimensions and expanding the application fields of optical devices.
Article
Optics
Haoxiang Chen, Qike Sun, Junqing Wang, Jianhong Yang, Hao Jia
Summary: This paper investigates the coupling strategy in the silicon-based dual-waveguide coupled-mode system and proposes a method to change the transmission coefficient by adjusting the mode coupling between waveguides. By customizing the dispersion curves of the waveguides through temperature control, the coupling coefficient can be changed without altering the waveguide geometry. Prototype of variable optical attenuators for different modes is demonstrated, and different interference patterns can be generated by cascading mode converters. A reconfigurable optical tweezer capable of manipulating nanoscale particles is also demonstrated. This methodology has potential applications in flexible multimode optical networks and labs on chip.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Optics
He Xueqing, Zhai Yuanbo, Li Pengfei
Summary: This study investigates a graphene V-groove hybrid plasmonic waveguide and analyzes the influence of geometric parameters and graphene chemical potential on the fundamental hybrid plasmon mode supported by the structure. By increasing the number of grooves and reducing the chemical potential of graphene, the effective area of the hybrid mode can be effectively compressed, with a reduction of two orders of magnitude compared to the structure without grooves. Although the transmission length is reduced, the figure of merit is increased by 34.5%-88.5%. Additionally, the crosstalk between two adjacent graphene V-groove hybrid plasmonic waveguides is analyzed, and the minimum distance without crosstalk between the waveguides can be reduced to 22 μm by optimizing the groove geometry and adjusting the chemical potential of graphene.
ACTA OPTICA SINICA
(2023)
Article
Engineering, Electrical & Electronic
Xuanru Zhang, Tie Jun Cui
Summary: The study introduces a novel toroidal plasmonic resonator that tightly compacts all resonance modes and reduces radiation loss, achieving a high quality factor. A trapped mode is excited by introducing a slit perturbation, doubling the confinement effect. The on-chip excitation of the trapped mode is analyzed, showing good agreement between experimental results and numerical simulations.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
M. J. Maleki, M. Soroosh
Summary: This work presents a novel plasmonic structure for guiding surface plasmon polaritons, which can serve as a fundamental waveguide in various plasmonic devices. The designed waveguide exhibits low loss, long coupling length, and compact size, making it suitable for integration in photonic circuits and different devices.
OPTICAL AND QUANTUM ELECTRONICS
(2023)
Article
Optics
F. Haddadan, M. Soroosh
Summary: In this paper, a plasmonic waveguide with a sandwiched SiO2 channel between a graphene layer and a silicon ridge is designed. By adjusting the chemical potential of graphene, low propagation loss is achieved. Furthermore, a 4-to-2 plasmonic priority encoder is proposed, which shows good contrast ratio and cross-talk at the working wavelength, with a relatively small area suitable for optical integrated circuits.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Polymer Science
Yue Yang, Jiawen Lv, Baizhu Lin, Yue Cao, Yunji Yi, Daming Zhang
Summary: An all-optical switch based on graphene-assisted polymer with the E-01(x) mode is proposed, which can reduce absorption loss and achieve power consumption of 9.5 mW, propagation loss of 0.01 dB/cm, and switching time of 127 μs (rise)/125 μs (fall) in the right position. The switch shows potential for low loss and full polarization optical control applications.
Article
Engineering, Electrical & Electronic
Muzzamal Iqbal Shaukat, Montasir Qasymeh, Hichem Eleuch
Summary: This study investigates the emergence of solitons in plasmonic graphene waveguides in the presence of optical and microwave fields. Electronically controlled coupled optical solitons can be achieved by altering the self- and cross-modulation terms through proper electrical biasing and doping concentration.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2022)
Article
Optics
Hideo Iizuka, Shanhui Fan
Summary: A non-equilibrium system consisting of two slabs separated by a vacuum gap shows that by placing an additional thin layer on one slab's exterior surface and changing its dielectric permittivity, the force on the slab can be tuned or switched. A switch for non-equilibrium Casimir force, using a VO2 thin film on the exterior surface, exhibits a sharp transition in Casimir force with temperature when the system is out of equilibrium.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2021)
Article
Engineering, Mechanical
Xiaopeng Li, Ziqi Yu, Hideo Iizuka, Taehwa Lee
Summary: This letter presents the design and experimental demonstration of extremely asymmetric flexural wave near-unit absorption and unidirectional zero reflection at the exceptional point using a metalayer composed of a pair of loss-induced asymmetrical resonators. The mechanism behind such extremely asymmetric behaviors is explored, and it is found that the exceptional point and critical coupling condition are simultaneously fulfilled by the metalayer. A design of broadband absorption is further suggested and validated through numerical simulation.
EXTREME MECHANICS LETTERS
(2022)
Article
Chemistry, Physical
Shingo Ohta, Hiroshi Nozaki, Liang Wang, Hongfei Jia, Nikhilendra Singh, Timothy Arthur, Daniel Hashemi, Hideo Iizuka
Summary: Inorganic solid ion conductors are important electrolytes for high-performance lithium-ion batteries and fuel cells. Previously developed inorganic ion conductors from natural minerals have low conductivity due to strong bonding between mobile ions and anions. In this study, a two-dimensional van der Waals inorganic proton conductor with higher conductivity by inserting protons into halogen vdW layers is presented. This provides a new pathway for the development of high-performance LIBs and FCs.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Optics
Ziqi Yu, Xiaopeng Li, Taehwa Lee, Hideo Iizuka
Summary: We investigated the near-field radiative heat transfer in a three-body system made of Weyl semimetals. Our results show that at infinitesimal temperature gradient, the rotation of the middle and right bodies can suppress heat transfer, but by tuning the rotation and cavity asymmetry, a higher heat transfer ratio can be achieved.
Article
Physics, Applied
Ryohei Tsuruta, Xiaopeng Li, Ziqi Yu, Hideo Iizuka, Taehwa Lee
Summary: Soft reconfigurable acoustic absorbers were demonstrated using flexible tubular resonators. The compliant structure of the tube absorbers promotes acoustic-structure coupling and exhibits hybrid resonances of acoustic and structural modes. The soft walls of the resonators decrease the resonance frequencies for low-frequency absorption by reducing the effective sound speed inside the tube.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Multidisciplinary
Kenichi Yatsugi, Tsuneya Yoshida, Tomonari Mizoguchi, Yoshihito Kuno, Hideo Iizuka, Yukihiro Tadokoro, Yasuhiro Hatsugai
Summary: This article presents experimental observations of topological edge states and bulk Chern numbers in a tunable electric circuit system. By accurately engineering the admittance matrix of the system using variable capacitors, the authors were able to emulate a topological phase transition and observe the corresponding edge states and bulk Chern numbers.
COMMUNICATIONS PHYSICS
(2022)
Article
Thermodynamics
Ziqi Yu, Xiaopeng Li, Taehwa Lee, Hideo Iizuka
Summary: The study demonstrates that significant enhancement of heat transfer can be achieved by introducing multilayer Weyl semimetals and simultaneously modulating rotation and material loss. By tuning the rotation angle and off-diagonal components of the permittivity tensor in the multilayer system, optimal heat transfer enhancement can be realized.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Engineering, Mechanical
Keita Funayama, Kenichi Yatsugi, Atsushi Miura, Hideo Iizuka
Summary: In this study, the tunability of coupling phenomena between topological waveguides was experimentally investigated using MEMS technology. Wide and fine tuning of the coupling strength was achieved by adjusting the distance between waveguides and the localization length. This is crucial for large-scale integrated topological circuits and systems.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Optics
Hideo Iizuka, Shanhui Fan
Summary: The article discusses systems with multiple plates, where the positions and temperatures of the plates are influenced by non-equilibrium Casimir forces and heat transfer. Through a feedback control scheme, the position of a plate can be controlled to follow a prescribed trajectory. Simulations on two-plate and three-plate systems are used to illustrate this concept. The results highlight the potential of using feedback control schemes in mechanical systems affected by quantum and thermal fluctuations.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2022)
Correction
Optics
Ziqi Yu, Xiaopeng LI, Taehwa Lee, Hideo Iizuka
Review
Physics, Multidisciplinary
Taehwa Lee, Xiaopeng Li, Ziqi Yu, Tsuyoshi Nomura, Ercan M. M. Dede, Hideo Iizuka
Summary: This review discusses the fundamental understanding of coupled resonance by comparing coupled mode theory (CMT) and harmonic oscillator model (HOM), and provides an overview of recent research progress in the field. It also highlights emerging research areas related to coupled resonance.
FRONTIERS IN PHYSICS
(2022)
Article
Physics, Applied
Taro Ikeda, Etsumi Kojima, Shinya Sugiura, Hideo Iizuka
Summary: By tuning the resonance frequency of two coupled resonators, near 2 pi phase rotation and unity amplitude in the reflection wave can be achieved without the use of a metallic plate. We demonstrate this mechanism on a reflective graphene metasurface with a thickness less than 0.03 times the free space wavelength. In a wireless communication scenario, the actively tunable graphene metasurface can reflect or transmit an incident wave, providing a significant advantage over structures with metallic plates. The performance of the metasurface is discussed in terms of loss effects and deviation of the reflection phase.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Multidisciplinary Sciences
Kenichi Yatsugi, Shrinathan Esakimuthu Pandarakone, Hideo Iizuka
Summary: We experimentally demonstrate the existence of higher-order topological corner states in a breathing kagome lattice. The winding direction of each coil is engineered to hold C-3 symmetry in each triangle unit cell, allowing the emergence of higher-order topological corner states. Moreover, by tuning the distances between the coils, the topological and trivial phases can be switched. The observed corner states in the topological phase are confirmed through admittance measurements, and we illustrate the wireless power transfer between corner states, as well as between the bulk and corner states.
SCIENTIFIC REPORTS
(2023)
Article
Thermodynamics
Ziqi Yu, Xiaopeng Li, Taehwa Lee, Hideo Iizuka
Summary: We demonstrate tunable thermal rectification enabled by near-field radiative heat transfer between two Weyl semimetal nanoparticles above graphene nanoribbons by rotating the particles and varying their loss factors. Through the rotation, the thermal rectification is significantly enhanced thanks to the nonreciprocal particles and the substrate that are more strongly coupled than the counterpart systems having reciprocal particles. Nonreciprocal particles induce spinning Poynting vectors, whose directions can be controlled by rotating the particles and can selectively couple to surface modes excited in the graphene nanoribbons.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Engineering, Mechanical
Xiaopeng Li, Ziqi Yu, Hideo Iizuka, Taehwa Lee
Summary: In this work, an LR-shunted mechanical resonator was studied for the observation of the exceptional point. By varying the shunting circuit parameters, the non-Hermitian degeneracy, namely the exceptional point, was supported. The design was verified through numerical analysis and experimental measurements, and the LR-shunted resonator allows for dynamic encircling of an exceptional point due to external stimuli.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
