Article
Chemistry, Analytical
Fateme Nazarzadeh, Abbas Ali Heidari
Summary: This paper presents a wideband flat lens antenna based on conformal transformation optics (CTO) with low reflection and good performance. Physical space optimization and optical path rescaling are applied to eliminate singular refractive index values and reduce reflection, resulting in an implementable all-dielectric isotropic medium. The designed flat lens operates in a wide frequency bandwidth, with an S-11 value of less than -15 dB in the frequency range of 13 to 30 GHz.
Article
Optics
Fateme Nazarzadeh, Abbas Ali Heidari
Summary: This study presents a high-performance wideband flat reflector designed using conformal transformation optics, with reduced device dispersion and wideband operation characteristics.
Article
Materials Science, Multidisciplinary
Yichao Liu, Fei Sun, Yungui Ma, Zheng Wang, Yuan Liu
Summary: This study proposes a new method for achieving highly directional radiation using near-zero-index-featured resonators, and demonstrates the feasibility of multi-band highly directional radiation through numerical simulations.
RESULTS IN PHYSICS
(2022)
Article
Multidisciplinary Sciences
Ali Abdolali, Hooman Barati Sedeh, Mohammad Hosein Fakheri, Chen Shen, Fei Sun
Summary: This study proposes a design principle for achieving an Arbitrary Shape Magnifying Lens (ASML) using transformation acoustics methodology, capable of realizing far-field high resolution images and breaking the diffraction limit. The obtained material behaves as an Acoustic Null Medium (ANM), characterized by homogeneity and independence from perturbations in the geometry of the lens.
SCIENTIFIC REPORTS
(2021)
Article
Optics
Chenglong Wang, Xiang Guo, Xidong Wu
Summary: This paper proposes and investigates a graphene plasmonic lens with an electrically tunable focal length. By controlling the gate voltage of graphene, the lens can be continuously tuned from a Maxwell Fisheye lens to a Luneburg lens, and excellent focusing performances are achieved.
Article
Mathematics, Applied
Yayun Chen, Tongzhu Li
Summary: In this paper, the n-dimensional spacelike conformal Einstein hypersurfaces are completely classified up to a conformal transformation in Rn+1 1 .
Review
Chemistry, Multidisciplinary
Lin Xu, Huanyang Chen
Summary: This paper discusses the method of controlling electromagnetic waves and other wave dynamics through coordinate transformations, and explores the design and application of transformation media. Examples of achieving transformation media by artificially structured units from conventional materials are summarized. These concepts can be extended to control other types of waves, making them useful for multi-physics designs.
ADVANCED MATERIALS
(2021)
Article
Computer Science, Information Systems
Ruisi Ge, Ryan Striker, Benjamin Braaten
Summary: This study investigates the influence of a passive conformal metasurface on a conventional patch antenna, achieving phase shifting by changing the metasurface's curvature. Three low-cost conformal prototypes were fabricated and tested, demonstrating up to 20 degrees of beam shifting and reasonable gain increase. Compared with similar research, this antenna system is fully passive and independent of the conventional patch antenna, making it easy to implement with other antenna research, especially for low power consumption beam steering systems.
Article
Multidisciplinary Sciences
Lizhen Lu, Kun Ding, Emanuele Galiffi, Xikui Ma, Tianyu Dong, J. B. Pendry
Summary: The study demonstrates the visualization of certain symmetries in a transformed coordinate space inspired by transformation optics, shedding light on underlying topological transitions. By projecting a system from a higher-dimensional virtual space to a lower-dimensional real space, a topologically non-trivial system can be constructed, with the topological invariant controlled through singularities in the conformal mapping for intuitive engineering of edge states. This confluence of transformation optics and topology is essential for developing new generation topological systems beyond photonics.
NATURE COMMUNICATIONS
(2021)
Article
Optics
Gianluca Ruffato, Hirokazu Kobayashi
Summary: This paper analyzes the caustics generated by conformal transformations of structured light beams, focusing on log-pol mapping and circular sector transformations. Using analytical models and numerical simulations, it shows how the generated caustics find the correct description in the framework of the roulette curves.
OPTICS COMMUNICATIONS
(2021)
Article
Physics, Multidisciplinary
Yongliang Zhang, Lina Shi, Che Ting Chan, Kin Hung Fung, Kai Chang
Summary: Recent advances in electromagnetic nonreciprocity have led to the exploration of geometrical approaches for engineering nonreciprocal electromagnetic response. In this study, we introduce the concept of generalized electromagnetic continua composed of structured points with additional degrees of freedom beyond coordinate transformation. Our findings show that general nonreciprocal media possess a unique time-varying Riemannian metric structure with local spinning components. This theory not only provides insights into the fundamental understanding of electromagnetic nonreciprocity, but also offers a practical principle for designing nonreciprocal devices through frame transformation.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Kang-Ping Ye, Wen-Jin Pei, Zhong-Hao Sa, Huanyang Chen, Rui-Xin Wu
Summary: The study experimentally demonstrated the effects of superscatterer and invisible gateway in stopping electromagnetic wave propagation in an air channel, providing a new platform for the design of future illusion devices.
PHYSICAL REVIEW LETTERS
(2021)
Article
Optics
Jakub Belin, Johannes Courtial, Tomas Tyc
Summary: Lens stars are composed of identical thin lenses arranged in a regular star shape, suitable for building ideal-lens TO devices. Ray trajectories in lens stars are found to be piecewise straight approximations of conic sections, and the concept is extended to Platonic lenses for further study. The research contributes to the understanding of TO with ideal lenses.
Article
Optics
Zhiwei Sun, Chao Liu, Ruolei Xu, Heling Gong, Xiaobo Xuan, Run Liu, Mingzhu Du, Hailin Cao
Summary: A novel method for discretization of the Luneburg lens is proposed, achieving higher efficiency based on effective medium theory. The feasibility of the discretization method is validated by a discrete Luneburg lens fabricated using 3D printing, which also features wave-patch reduction.
Article
Optics
Brian Slovick, Josh Hellhake
Summary: We proposed an optimization method for designing unidirectional invisibility cloaks by minimizing the forward scattering amplitude of the cloaked object. The use of the optical theorem simplifies the evaluation and integration of the scattering amplitude, making the optimization process computationally efficient. Several gradient-permittivity unidirectional cloaks were successfully designed to reduce scattering from metallic targets of varying sizes and shapes.
PHOTONICS RESEARCH
(2022)
Article
Multidisciplinary Sciences
Pengfei Zhao, Guoxiong Cai, Huanyang Chen
Summary: We present a novel method for designing transformation optical devices based on electrostatics. The method utilizes the transformation of electrostatic field to achieve a new refractive index distribution, where wave-fronts and energy flux lines correspond to equipotential surfaces and electrostatic flux lines, respectively. The method can be used to design multipole lenses and explain the illusion effects of some multipole lenses.
Article
Optics
Jue Li, Yangyang Zhou, Huanyang Chen
Summary: In this study, a solid immersion square Maxwell's fish-eye lens is proposed to achieve broadband achromatic super-resolution imaging based on transformation optics at microwave frequencies. A super-resolution information transmission channel is also designed for long-distance multi-source super-resolution information transmission.
CHINESE OPTICS LETTERS
(2022)
Article
Optics
Shuwen Xue, Chuanjie Hu, Miao Zhang, Huanyang Chen
Summary: Cats' fascinating eyes with various colors and strong night vision ability have been studied to reveal the secrets behind them. Researchers have found that cats' eyes can be considered as special lenses with photonic crystals playing a key role. Integrating photonic crystals into a Luneburg lens greatly improves the light focusing intensity, offering inspiration for designing more interesting and practical devices.
CHINESE OPTICS LETTERS
(2022)
Article
Physics, Multidisciplinary
Qilin Duan, Ying Chen, Huanyang Chen
Summary: This paper designs self-collimation, beam splitting, and negative refraction effects in photonic crystals based on metallic pairs, achieving a broadband and wide-angle self-collimation effect, beam splitting effect, and flat lens effect.
Article
Engineering, Electrical & Electronic
Yufang Wang, Yuehe Ge, Zhizhang Chen, Xin Liu, Jixiong Pu, Kaiting Liu, Huanyang Chen, Yang Hao
Summary: The study demonstrates a high-efficiency broadband ultrathin metasurface incorporating metallic gratings and double-split-ring resonators. The metasurface has multiple functionalities, generating beams with different orders and vortex beams with various orbital angular momentum modes in both reflection and transmission spaces.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2022)
Article
Optics
Yali Zeng, Jinying Xu, Wen Xiao, Zhilin Yang, Huanyang Chen, Yineng Liu
Summary: In this work, a black phosphorus achiral metasurface was proposed and the chiroptical response arising from extrinsic 2D-chirality in the mid-infrared regime was theoretically studied. The achiral metasurface is composed of a monolayer black phosphorus sheet sandwiched by a silver ring array and dielectric spacer stacking on a silver substrate. It was found that the achiral metasurface exhibits giant circular conversion dichroism (CCD) at oblique incidence due to the cooperative interaction between the BP anisotropic surface plasmon modes and localized surface plasmons in the metal rings. The chiroptical response can be dynamically modulated by controlling the doping concentration of BP, and a multiband phenomenon for CCD response occurs when tuning the thickness of the spacer. The proposed hybrid achiral metasurface provides more flexible opportunities for applications such as active polarization modulators, biosensors, and chiral detection.
Article
Physics, Applied
Chuanjie Hu, Yadong Xu, Shan Zhu, Huanyang Chen
Summary: Phase-gradient metagratings, integrating homogeneous dielectric materials with gradient thickness into periodical metallic slits, have shown unconventional abilities to manipulate electromagnetic waves, with nearly perfect broadband transmission achieved in a passive phased metagrating based on mode conversion. The effectiveness of the scheme is validated by theoretically designing anomalous scattering and planar metalenses with excellent efficiency, proving the potential application of this structure in other physical fields such as acoustics and water waves.
PHYSICAL REVIEW APPLIED
(2022)
Review
Materials Science, Multidisciplinary
Bing Duan, Bei Wu, Jin-hui Chen, Huanyang Chen, Da-Quan Yang
Summary: This paper reviews the recent advances of deep learning in photonic structure design and optical data analysis, based on the two major learning paradigms of supervised learning and unsupervised learning. It highlights optical neural networks as novel computing architectures with high parallelism and low energy consumption.
FRONTIERS IN MATERIALS
(2022)
Article
Physics, Applied
Yangyang Zhou, Zhanlei Hao, Pengfei Zhao, Huanyang Chen
Summary: This work introduces a new approach to achieve super-resolution imaging without the need for drain assistance in Maxwell's fish-eye lens. By embedding the lens in an exterior coating inspired by the solid immersion concept, the solution addresses the criticisms and debates surrounding the physics of super-resolution phenomena in MFEL. The total reflection at the outer solid-immersion interface and the native perfect focusing of MFEL contribute to the formation of a super-resolution image in the air.
PHYSICAL REVIEW APPLIED
(2022)
Article
Optics
Yangyang Zhou, Jue Li, Wen Xiao, Huanyang Chen
Summary: This study introduces a generalized conformal Luneburg lens (GCLL) based on conformal transformation optics for achieving broadband achromatic and highly efficient quasi-far-field super-focusing. The lens has a relatively high numerical aperture and sub-diffraction-limited resolution, and it is designed using gradient metamaterials.
Article
Materials Science, Multidisciplinary
Lei Zhao, Bei Wu, Yao Niu, Shengke Zhu, Ye Chen, Huanyang Chen, Jin-hui Chen
Summary: With the rapid development of deep learning and computing power, human-computer interactions and interfaces have become topics of interest in industrial and academic research. Hand gesture recognition, as a new way of studying human-computer interactions, poses challenges due to the complexity and flexibility of the human hand. This research presents a robust and cost-effective gesture recognition system using soft optoelectronic sensors and a deep learning network, achieving high recognition accuracy for hand gestures.
ADVANCED MATERIALS TECHNOLOGIES
(2022)
Article
Physics, Applied
Chuanjie Hu, Yuhang Yin, Huanyang Chen
Summary: This study demonstrates the feasibility of achieving three-dimensional omnidirectional passive acoustic illusion using Fabry-Perot resonances. The research has the potential for application in modern acoustic illusion devices, such as camouflage for antisonar detection.
PHYSICAL REVIEW APPLIED
(2022)
Article
Astronomy & Astrophysics
Wen Xiao, Pengfei Zhao, Yixiao Ge, Sicen Tao, Yali Zeng, Lin Xu, Huanyang Chen
Summary: de Sitter space is an important solution of Einstein's field equation that explains the accelerated expansion of the Universe. In this study, we propose a de Sitter space model based on the equivalence between static curved space-time and isotropic optical medium. We discover a topological cosmic string kernel in the center of the generalized de Sitter space, which can deflect light in different ways. By implementing a multiple source illusion effect, we find that the energy flow obeys the topological Poincare-Hopf theorem.
Article
Optics
Tao Hou, Huanyang Chen
Summary: This paper demonstrates the analogy between the anisotropic Kepler problem and the non-rotationally-symmetric Eaton lens through numerical calculations and simulations. When the mass ratio is greater than 1, the non-rotationally-symmetric Eaton lens can simulate and reproduce the periodic orbits and chaotic characteristics of the anisotropic Kepler problem in geometric and wave optics. Additionally, the study reveals that the deflected beam in non-rotationally-symmetric Eaton lens can have scatterings in various directions, which are influenced by the incident direction and mass ratio.
Article
Nanoscience & Nanotechnology
Tao Hou, Sicen Tao, Haoran Mu, Qiaoliang Bao, Huanyang Chen
Summary: By combining transformation optics and van der Waals layered materials, a proposed invisibility concentrator utilizes a thin layer of alpha-MoO3 to wrap around a cylinder, inheriting invisibility and energy concentration effects. Analytical calculation and numerical simulations confirm the device's functionalities, providing guidelines for future experimental verification.
