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Sun Y, Cai B, Yang L, Wu L, Cheng Y, Luo H, Chen F, Li X. High-Gain Dual-Polarization Microstrip Antenna Based on Transmission Focusing Metasurface. MATERIALS (BASEL, SWITZERLAND) 2024; 17:3730. [PMID: 39124394 PMCID: PMC11313525 DOI: 10.3390/ma17153730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 06/08/2024] [Accepted: 07/24/2024] [Indexed: 08/12/2024]
Abstract
In this paper, a single-feed microstrip antenna (MA) equipped with a transmission-mode focusing metasurface (MS) is proposed to achieve dual-polarization capabilities and superior high-gain radiation performance. The original-feed MA comprises two distinct layers of coaxial-fed tangential patches, enabling it to emit a circular polarization (CP) wave with a gain of 3.5 dBic at 5.6 GHz and linear polarization (LP) radiation with a gain of 4 dBi at 13.7 GHz. To improve the performance of the single-feed MA, a dual-polarization transmission focusing MS is proposed and numerically substantiated. By positioning the originally designed MA at the focal point of the MS, we create a transmission-mode MS antenna system capable of achieving CP and LP radiations with the significantly higher gains of 12.9 dBic and 14.8 dBi at 5.6 GHz and 13.7 GHz, respectively. Measurements conducted on the fabricated dual-polarization focusing MS antenna closely align with the simulation results, validating the effectiveness of our approach. This work underscores the significant potential of dual-polarization high-speed data systems and offers a practical solution for enhancing antenna gains in contemporary wireless communication systems.
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Affiliation(s)
- Yibo Sun
- School of Information Science and Engineering, Engineering Research Center for Metallurgical Automation and Detecting Technology Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, China; (Y.S.); (B.C.); (H.L.); (F.C.)
| | - Bin Cai
- School of Information Science and Engineering, Engineering Research Center for Metallurgical Automation and Detecting Technology Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, China; (Y.S.); (B.C.); (H.L.); (F.C.)
| | - Lingling Yang
- School of Electronic Engineering, Wuhan Open University, Wuhan 430205, China;
| | - Ling Wu
- School of Physics and Electronic Information Engineering, Hubei Engineering University, Xiaogan 432000, China;
| | - Yongzhi Cheng
- School of Information Science and Engineering, Engineering Research Center for Metallurgical Automation and Detecting Technology Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, China; (Y.S.); (B.C.); (H.L.); (F.C.)
- Key Laboratory of High Temperature Electromagnetic Materials and Structure of MOE, Wuhan University of Science and Technology, Wuhan 430081, China
| | - Hui Luo
- School of Information Science and Engineering, Engineering Research Center for Metallurgical Automation and Detecting Technology Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, China; (Y.S.); (B.C.); (H.L.); (F.C.)
- Key Laboratory of High Temperature Electromagnetic Materials and Structure of MOE, Wuhan University of Science and Technology, Wuhan 430081, China
| | - Fu Chen
- School of Information Science and Engineering, Engineering Research Center for Metallurgical Automation and Detecting Technology Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, China; (Y.S.); (B.C.); (H.L.); (F.C.)
- Key Laboratory of High Temperature Electromagnetic Materials and Structure of MOE, Wuhan University of Science and Technology, Wuhan 430081, China
| | - Xiangcheng Li
- School of Physics and Electronic Information Engineering, Hubei Engineering University, Xiaogan 432000, China;
- Key Laboratory of High Temperature Electromagnetic Materials and Structure of MOE, Wuhan University of Science and Technology, Wuhan 430081, China
- The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China
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Wang L, Liu N, Wu C, Chen G. Dynamical encircling of multiple exceptional points in anti-PT symmetry system. OPTICS EXPRESS 2024; 32:21616-21628. [PMID: 38859511 DOI: 10.1364/oe.524678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 05/21/2024] [Indexed: 06/12/2024]
Abstract
Exceptional points (EPs) in non-Hermitian systems have turned out to be at the origin of many intriguing effects with no counterparts in Hermitian cases. A typically interesting behavior is the chiral mode switching by dynamically winding the EP. Most encircling protocols focus on the two-state or parity-time (PT) symmetry systems. Here, we propose and investigate the dynamical encircling of multiple EPs in an anti-PT-symmetric system, which is constructed based on a one-dimensional lattice with staggered lossy modulation. We reveal that dynamically encircling the multiple EPs results in the chiral dynamics via multiple non-Hermiticity-induced nonadiabatic transitions, where the output state is always on the lowest-loss energy sheet. Compared with the PT-symmetric systems that require complicated variation of the gain/loss rate or on-site potentials, our system only requires modulations of the couplings which can be readily realized in various experimental platforms. Our scheme provides a route to study non-Hermitian physics by engineering the EPs and implement novel photonic devices with unconventional functions.
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Hu H, Fu X, Qi J, Zhang S, Wu Q, Lu Y, Chen Z, Chen J, Yu X, Wang X, Sun Q, Xu J. Omni-polarized Faraday isolator based on non-Hermitian Faraday system. OPTICS EXPRESS 2024; 32:18594-18604. [PMID: 38859012 DOI: 10.1364/oe.522109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 04/22/2024] [Indexed: 06/12/2024]
Abstract
Non-Hermitian systems have recently attracted significant attention in photonics due to the realization that the interplay between gain and loss can lead to entirely new and unexpected features. Here, we propose and demonstrate a non-Hermitian Faraday system capable of non-reciprocal omni-polarizer action at the exceptional point. Notably, both forward and backward propagating light with arbitrary polarization converge to the same polarization state. Leveraging the robustness and non-reciprocity of the non-Hermitian Faraday system, we realize an omni-polarized Faraday isolator that can effectively isolate any polarized light without the need for a polarizer at the incident port of backward propagation. Remarkably, under the given parameter configuration, the isolator achieves a maximum isolation ratio of approximately 100 dB and a minimum isolation ratio of around 45 dB for various polarized light, accompanied by near-zero insertion loss. Furthermore, our research reveals the remarkable tolerance of the non-Hermitian Faraday isolator to nonlinear effects. This unique characteristic allows us to harness nonlinear effects to achieve various optical functions, all while maintaining excellent isolation performance. The proposed non-Hermitian Faraday system paves the way for the realization of magnetically or optically switchable non-reciprocal devices.
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Shu X, Zhong Q, Hong K, You O, Wang J, Hu G, Alù A, Zhang S, Christodoulides DN, Chen L. Chiral transmission by an open evolution trajectory in a non-Hermitian system. LIGHT, SCIENCE & APPLICATIONS 2024; 13:65. [PMID: 38438358 PMCID: PMC10912664 DOI: 10.1038/s41377-024-01409-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 01/28/2024] [Accepted: 02/12/2024] [Indexed: 03/06/2024]
Abstract
Exceptional points (EPs), at which two or more eigenvalues and eigenstates of a resonant system coalesce, are associated with non-Hermitian Hamiltonians with gain and/or loss elements. Dynamic encircling of EPs has received significant interest in recent years, as it has been shown to lead to highly nontrivial phenomena, such as chiral transmission in which the final state of the system depends on the encircling handedness. Previously, chiral transmission for a pair of eigenmodes has been realized by establishing a closed dynamical trajectory in parity-time- (PT-) or anti-PT-symmetric systems. Although chiral transmission of symmetry-broken modes, more accessible in practical photonic integrated circuits, has been realized by establishing a closed trajectory encircling EPs in anti-PT-symmetric systems, the demonstrated transmission efficiency is very low due to path-dependent losses. Here, we demonstrate chiral dynamics in a coupled waveguide system that does not require a closed trajectory. Specifically, we explore an open trajectory linking two infinite points having the same asymptotic eigenmodes (not modes in PT- and anti-PT-symmetric systems), demonstrating that this platform enables high-efficiency chiral transmission, with each eigenmode localized in a single waveguide. This concept is experimentally implemented in a coupled silicon waveguide system at telecommunication wavelengths. Our work provides a new evolution strategy for chiral dynamics with superior performance, laying the foundation for the development of practical chiral-transmission devices.
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Affiliation(s)
- Xiaoqian Shu
- Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China
- Zhejiang Lab, Hangzhou, 311121, China
| | - Qi Zhong
- CREOL, College of Optics and Photonics, University of Central Florida, Orlando, Florida, 32816, USA
| | - Kai Hong
- Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Oubo You
- Department of Physics, The University of Hong Kong, Hong Kong, China
| | - Jian Wang
- Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Guangwei Hu
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Andrea Alù
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, NY, 10031, USA
| | - Shuang Zhang
- Department of Physics, The University of Hong Kong, Hong Kong, China
| | | | - Lin Chen
- Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China.
- Shenzhen Huazhong University of Science and Technology Research Institute, Shenzhen, 518063, China.
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Fan B, Tang H, Wu P, Qiu Y, Jiang L, Lin L, Su J, Zhou B, Pan M. Actively Tunable "Single Peak/Broadband" Absorbent, Highly Sensitive Terahertz Smart Device Based on VO 2. MICROMACHINES 2024; 15:208. [PMID: 38398936 PMCID: PMC10890599 DOI: 10.3390/mi15020208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/26/2024] [Accepted: 01/26/2024] [Indexed: 02/25/2024]
Abstract
In recent years, the development of terahertz (THz) technology has attracted significant attention. Various tunable devices for THz waves (0.1 THz-10 THz) have been proposed, including devices that modulate the amplitude, polarization, phase, and absorption. Traditional metal materials are often faced with the problem of non-adjustment, so the designed terahertz devices play a single role and do not have multiple uses, which greatly limits their development. As an excellent phase change material, VO2's properties can be transformed by external temperature stimulation, which provides new inspiration for the development of terahertz devices. To address these issues, this study innovatively combines metamaterials with phase change materials, leveraging their design flexibility and temperature-induced phase transition characteristics. We have designed a THz intelligent absorber that not only enables flexible switching between multiple functionalities but also achieves precise performance tuning through temperature stimulation. Furthermore, we have taken into consideration factors such as the polarization mode, environmental temperature, structural parameters, and incident angle, ensuring the device's process tolerance and environmental adaptability. Additionally, by exploiting the principle of localized surface plasmon resonance (LSPR) accompanied by local field enhancement, we have monitored and analyzed the resonant process through electric field characterization. In summary, the innovative approach and superior performance of this structure provide broader insights and methods for THz device design, contributing to its theoretical research value. Moreover, the proposed absorber holds potential for practical applications in electromagnetic invisibility, shielding, modulation, and detection scenarios.
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Affiliation(s)
- Baodian Fan
- Key Laboratory of Green Perovskites Application of Fujian Provincial Universities, Fujian Jiangxia University, Fuzhou 350108, China; (B.F.); (Y.Q.); (L.J.); (L.L.)
| | - Hao Tang
- Key Laboratory of Information Functional Material for Fujian Higher Education, College of Physics and Information Engineering, Quanzhou Normal University, Quanzhou 362000, China; (H.T.); (P.W.); (J.S.); (B.Z.)
| | - Pinghui Wu
- Key Laboratory of Information Functional Material for Fujian Higher Education, College of Physics and Information Engineering, Quanzhou Normal University, Quanzhou 362000, China; (H.T.); (P.W.); (J.S.); (B.Z.)
| | - Yu Qiu
- Key Laboratory of Green Perovskites Application of Fujian Provincial Universities, Fujian Jiangxia University, Fuzhou 350108, China; (B.F.); (Y.Q.); (L.J.); (L.L.)
| | - Linqin Jiang
- Key Laboratory of Green Perovskites Application of Fujian Provincial Universities, Fujian Jiangxia University, Fuzhou 350108, China; (B.F.); (Y.Q.); (L.J.); (L.L.)
| | - Lingyan Lin
- Key Laboratory of Green Perovskites Application of Fujian Provincial Universities, Fujian Jiangxia University, Fuzhou 350108, China; (B.F.); (Y.Q.); (L.J.); (L.L.)
| | - Jianzhi Su
- Key Laboratory of Information Functional Material for Fujian Higher Education, College of Physics and Information Engineering, Quanzhou Normal University, Quanzhou 362000, China; (H.T.); (P.W.); (J.S.); (B.Z.)
| | - Bomeng Zhou
- Key Laboratory of Information Functional Material for Fujian Higher Education, College of Physics and Information Engineering, Quanzhou Normal University, Quanzhou 362000, China; (H.T.); (P.W.); (J.S.); (B.Z.)
| | - Miao Pan
- Key Laboratory of Information Functional Material for Fujian Higher Education, College of Physics and Information Engineering, Quanzhou Normal University, Quanzhou 362000, China; (H.T.); (P.W.); (J.S.); (B.Z.)
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Zhang X, Wang G, Liu J, Zuo S, Li M, Yang S, Jia Y, Gao Y. A switchable and tunable multifunctional terahertz polarization converter based on a graphene metasurface. Phys Chem Chem Phys 2023; 25:31948-31959. [PMID: 37975202 DOI: 10.1039/d3cp03796g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
We propose a switchable and tunable terahertz metasurface polarization converter based on graphene. The metasurface is composed of a bottom gold film, a lower SiO2 layer, an intermediate N-type graphene layer, an upper SiO2 layer, and a top layer of square graphene resonant rings. By using the CST Microwave Studio, we studied their polarization conversion properties. The results show that the metasurface enables a versatile range of functions, including x-to-y linear polarization conversion within the frequency range of 4.23-7 THz, the transformation of linearly polarized waves into right-hand circularly polarized and left-hand circularly polarized waves. Moreover, at 3.873 THz, the metasurface can exhibit circular dichroism (CD) with a high CD value of 0.7. Based on the effect, a strategy to detect three representative avian influenza viruses was proposed and tested, which implies that the metasurface can be applied in biosensing.
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Affiliation(s)
- Xin Zhang
- Electronic Engineering College, Heilongjiang University, Harbin, 150080, China.
| | - Guan Wang
- Electronic Engineering College, Heilongjiang University, Harbin, 150080, China.
| | - Jia Liu
- Electronic Engineering College, Heilongjiang University, Harbin, 150080, China.
| | - Shiyi Zuo
- Electronic Engineering College, Heilongjiang University, Harbin, 150080, China.
| | - Meichen Li
- Electronic Engineering College, Heilongjiang University, Harbin, 150080, China.
| | - Shuang Yang
- Electronic Engineering College, Heilongjiang University, Harbin, 150080, China.
| | - Yang Jia
- Electronic Engineering College, Heilongjiang University, Harbin, 150080, China.
- College of Communication and Electronic Engineering, Qiqihar University, Qiqihar 161000, China
| | - Yachen Gao
- Electronic Engineering College, Heilongjiang University, Harbin, 150080, China.
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Zhang Y, Feng Y, Zhao J. Graphene-Enabled Tunable Phase Gradient Metasurface for Broadband Dispersion Manipulation of Terahertz Wave. MICROMACHINES 2023; 14:2006. [PMID: 38004863 PMCID: PMC10672863 DOI: 10.3390/mi14112006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 10/26/2023] [Accepted: 10/27/2023] [Indexed: 11/26/2023]
Abstract
With the increasing demand for the miniaturization and flexibility of optical devices, graphene-based metasurfaces have emerged as a promising ideal design platform for realizing planar and tunable electromagnetic or optical devices. In this paper, we propose a tunable metasurface with low-dispersion phase gradient characteristics that is composed of an array of double-layer graphene ribbons sandwiched with a thin insulating layer and a polymer substrate layer with a gold ground plane. As two typical proof-of-concept examples, metasurfaces act as a planar prism and a planar lens, respectively, and the corresponding performances of tunable broadband dispersion are demonstrated through full-wave simulation experiments. By changing the Fermi level of each graphene ribbon individually to introduce abrupt phase shifts along the metasurface, the broadband continuous dispersion effect of abnormal reflection and beam focusing is achieved within a terahertz (THz) frequency region from 3.0 THz to 4.0 THz, and the dispersion results can be freely regulated by reconfiguring the sequence of Fermi levels via the bias voltage. The presented graphene metasurface provides an avenue for the dispersion manipulation of a broadband terahertz wave and may have great prospects in the fields of optics, imaging, and wireless communication.
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Affiliation(s)
- Yin Zhang
- School of Information Engineering, Nanjing University of Finance and Economics, Nanjing 210023, China;
- Department of Electronic Engineering, School of Electronic Science and Engineering, Nanjing University, Nanjing 210023, China;
| | - Yijun Feng
- Department of Electronic Engineering, School of Electronic Science and Engineering, Nanjing University, Nanjing 210023, China;
| | - Junming Zhao
- Department of Electronic Engineering, School of Electronic Science and Engineering, Nanjing University, Nanjing 210023, China;
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Hong K, Chen L. Mie scatterers bring a resonator to an exceptional point. LIGHT, SCIENCE & APPLICATIONS 2023; 12:216. [PMID: 37666827 PMCID: PMC10477206 DOI: 10.1038/s41377-023-01258-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
Exceptional points have given rise to many intriguing optical phenomena that are of fundamental importance for a variety of breakthrough technologies. The pre-defined Mie scatterers can bring a resonator to an exceptional point, and result in enhanced quality factor through coherently suppressing the backward scattering.
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Affiliation(s)
- Kai Hong
- Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Lin Chen
- Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China.
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Li A, Wei H, Cotrufo M, Chen W, Mann S, Ni X, Xu B, Chen J, Wang J, Fan S, Qiu CW, Alù A, Chen L. Exceptional points and non-Hermitian photonics at the nanoscale. NATURE NANOTECHNOLOGY 2023; 18:706-720. [PMID: 37386141 DOI: 10.1038/s41565-023-01408-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 04/25/2023] [Indexed: 07/01/2023]
Abstract
Exceptional points (EPs) arising in non-Hermitian systems have led to a variety of intriguing wave phenomena, and have been attracting increased interest in various physical platforms. In this Review, we highlight the latest fundamental advances in the context of EPs in various nanoscale systems, and overview the theoretical progress related to EPs, including higher-order EPs, bulk Fermi arcs and Weyl exceptional rings. We peek into EP-associated emerging technologies, in particular focusing on the influence of noise for sensing near EPs, improving the efficiency in asymmetric transmission based on EPs, optical isolators in nonlinear EP systems and novel concepts to implement EPs in topological photonics. We also discuss the constraints and limitations of the applications relying on EPs, and offer parting thoughts about promising ways to tackle them for advanced nanophotonic applications.
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Affiliation(s)
- Aodong Li
- Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, China
| | - Heng Wei
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Michele Cotrufo
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, NY, USA
| | - Weijin Chen
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Sander Mann
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, NY, USA
| | - Xiang Ni
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, NY, USA
| | - Bingcong Xu
- Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, China
| | - Jianfeng Chen
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Jian Wang
- Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, China
| | - Shanhui Fan
- Department of Electrical Engineering, Ginzton Laboratory, Stanford University, Stanford, CA, USA
- Department of Applied Physics, Stanford University, Stanford, CA, USA
| | - Cheng-Wei Qiu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore.
| | - Andrea Alù
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, NY, USA.
- Physics Program, Graduate Center, City University of New York, New York, NY, USA.
| | - Lin Chen
- Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, China.
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, China.
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Qin J, Wang M, Qiu CW. Graphene metasurface hits the point. LIGHT, SCIENCE & APPLICATIONS 2023; 12:110. [PMID: 37156789 PMCID: PMC10167302 DOI: 10.1038/s41377-023-01159-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Exceptional points pose exceptional difficulties to access and encircle. By simply gating graphene, it is now easier to hit the exceptional point.
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Affiliation(s)
- Jiazheng Qin
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Mengjia Wang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Cheng-Wei Qiu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117583, Singapore.
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