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Li C, Wang G, Peng M, Liu C, Feng T, Wang Y, Qin F. Reconfigurable Origami/Kirigami Metamaterial Absorbers Developed by Fast Inverse Design and Low-Concentration MXene Inks. ACS APPLIED MATERIALS & INTERFACES 2024; 16:42448-42460. [PMID: 39078617 DOI: 10.1021/acsami.4c07084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/31/2024]
Abstract
Reconfigurable metamaterial absorbers (MAs), consisting of tunable elements or deformable structures, are able to transform their absorbing bandwidth and amplitude in response to environmental changes. Among the options for building reconfigurable MAs, origami/kirigami structures show great potential because of their ability to combine excellent mechanical and electromagnetic (EM) properties. However, neither the trial-and-error-based design method nor the complex fabrication process can meet the requirement of developing high-performance MAs. Accordingly, this work introduces a deep-learning-based algorithm to realize the fast inverse design of origami MAs. Then, an accordion-origami coding MA is generated with reconfigurable EM responses that can be smoothly transformed between ultrabroadband absorption (5.5-20 GHz, folding angle α = 82°) and high reflection (2-20 GHz, RL > -1.5 dB, α = 0°) under y-polarized waves. However, the asymmetric coding pattern and accordion-origami deformation lead to typical polarization-sensitive absorbing performance (2-20 GHz, RL > -4 dB, α < 90°) under x-polarized waves. For the first time, a kirigami polarization rotation surface with switchable operation band is adapted to balance the absorbing performance of accordion-origami MA under orthogonal polarized waves. As a result, the stacked origami-kirigami MA maintains polarization-insensitive ultrabroadband absorption (4.4-20 GHz) at β = 0° and could be transformed into a narrowband absorber through deformation. Besides, the adapted origami/kirigami structures possess excellent mechanical properties such as low relative density, negative Poisson's ratio, and tunable specific energy absorption. Moreover, by modulating the PEDOT:PSS conductive bridges among MXene nanosheets, a series of low-concentration MXene-PEDOT:PSS inks (∼46 mg·mL-1) with adjustable square resistance (5-32.5 Ω/sq) are developed to fabricate the metamaterials via screen printing. Owing to the universal design scheme, this work supplies a promising paradigm for developing low-cost and high-performance reconfigurable EM absorbers.
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Affiliation(s)
- Changfeng Li
- Institute for Composites Science Innovation (InCSI), School of Materials Science and Engineering, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P.R. China
| | - Ge Wang
- Institute for Composites Science Innovation (InCSI), School of Materials Science and Engineering, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P.R. China
| | - Mengyue Peng
- Institute for Composites Science Innovation (InCSI), School of Materials Science and Engineering, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P.R. China
| | - Chenwei Liu
- Institute for Composites Science Innovation (InCSI), School of Materials Science and Engineering, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P.R. China
| | - Tangfeng Feng
- Institute for Composites Science Innovation (InCSI), School of Materials Science and Engineering, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P.R. China
| | - Yunfei Wang
- Institute for Composites Science Innovation (InCSI), School of Materials Science and Engineering, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P.R. China
| | - Faxiang Qin
- Institute for Composites Science Innovation (InCSI), School of Materials Science and Engineering, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P.R. China
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Zhang L, Sun H, Chen Z, Tang R, Yang J, Li W. Design and Numerical Modeling of Terahertz Metasurface with Dual Functions of Sensing and Filtering. SENSORS (BASEL, SWITZERLAND) 2024; 24:4823. [PMID: 39123870 PMCID: PMC11314842 DOI: 10.3390/s24154823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 07/21/2024] [Accepted: 07/22/2024] [Indexed: 08/12/2024]
Abstract
This study proposes a dual-functional terahertz device based on the Dirac semimetal, serving as both a sensing element and a band-pass filter. The device's operating mode can switch between these two functions by utilizing the phase transition property of vanadium dioxide (VO2). When VO2 is in the insulating state, the device functions as a sensing element. The simulation results demonstrate an impressive refractive index sensitivity of 374.40 GHz/RIU (Refractive Index Unit). When VO2 is in the metallic state, the device functions as a band-pass filter, exhibiting a center frequency of 2.01 THz and a 3 dB fractional bandwidth of 0.91 THz. The integration of these dual functionalities within a single terahertz device enhances its utility in both sensing and filtering applications.
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Affiliation(s)
| | | | - Zhe Chen
- School of Information Science and Engineering, Yunnan University, Kunming 650000, China; (L.Z.); (H.S.); (R.T.); (J.Y.); (W.L.)
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Feng H, Meng H, Wang G, Liu J, Zhang X, Li M, Yang S, Jia Y, Du H, Gao Y, Gao Y. A tunable ultra-broadband and ultra-high sensitivity far-infrared metamaterial absorber based on VO 2 and graphene. Phys Chem Chem Phys 2024; 26:14919-14929. [PMID: 38738775 DOI: 10.1039/d4cp00331d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2024]
Abstract
We proposed a far-infrared tunable metamaterial absorber using vanadium dioxide (VO2) and graphene as controlling materials. The properties of the absorber are investigated theoretically using the finite-difference time-domain (FDTD) technique. It was found that when the Fermi energy level of graphene is fixed at zero, VO2 is in the insulated state, and the metasurface exhibits far-infrared broadband absorption performance, with absorptance exceeding 90% in the wavelength range of 12.6 μm to 23.2 μm. In addition, by elevating the Fermi energy level of graphene, the absorption bandwidth of the device is expanded continuously. When the VO2 is in the metallic state, the device can flexibly transform into a far-infrared narrowband absorber. The device also has the advantage of being insensitive to changes in polarization and incident angle. The origin of the absorption and the tuning principle of the device were analyzed and verified successfully by using an equivalent circuit model (ECM). Besides, we also studied the refraction index sensing characteristics of the absorber. Surprisingly, the absorber exhibits excellent sensing characteristics, and its sensitivity (S) reaches 14.108 μm per RIU and the figure of merit (FOM) is 6.13 per RIU.
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Affiliation(s)
- Hengli Feng
- Electronic Engineering College, Heilongjiang University, Harbin, 150080, China.
| | - Hongyan Meng
- Electronic Engineering College, Heilongjiang University, Harbin, 150080, China.
- College of Communication and Electronic Engineering, Qiqihar University, Qiqihar 161000, China
| | - Guan Wang
- Electronic Engineering College, Heilongjiang University, Harbin, 150080, China.
| | - Jia Liu
- Electronic Engineering College, Heilongjiang University, Harbin, 150080, China.
| | - Xin Zhang
- 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
| | - Hanmo Du
- Electronic Engineering College, Heilongjiang University, Harbin, 150080, China.
| | - Yang Gao
- Electronic Engineering College, Heilongjiang University, Harbin, 150080, China.
| | - Yachen Gao
- Electronic Engineering College, Heilongjiang University, Harbin, 150080, China.
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Zhang X, Sun A, Jiang Z, Liu C, Wang S, Kong Y. Tunable and switchable multifunctional terahertz meta-mirror based on graphene and vanadium dioxide. Phys Chem Chem Phys 2024; 26:13915-13922. [PMID: 38666431 DOI: 10.1039/d4cp00172a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2024]
Abstract
We design a multifunctional THz polarization modulation meta-mirror integrated with polarization conversion and dichroism functions switched by temperature and voltage. The meta-mirror is composed of two-layered graphene metasurfaces and a layer of vanadium dioxide (VO2) on a gold film substrate. Linear-to-linear polarization conversion and linear dichroism (LD) can be switched by temperature control in the VO2 film and Fermi level adjustments in the graphene metasurfaces, where the polarization conversion ratio (PCR) is higher than 0.9 in the range of 2.89 THz to 4.02 THz, LD value reached a maximum of 0.6 at 3.84 THz, and linear-to-circular polarization conversion and circular dichroism (CD) can also be tuned with ellipticity higher than 0.9 in the range of 2.32 THz to 2.69 THz and CD value as high as 0.71 at 2.45 THz. The proposed meta-mirror is the first THz metamaterial device integrating four switchable functions, including linear-to-linear polarization conversion, linear-to-circular polarization conversion, linear dichroism and circular dichroism. The meta-mirror is a promising design for compact system integration in THz imaging, sensing and biological detection applications.
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Affiliation(s)
- Xinzhi Zhang
- Computational Optics Laboratory, School of Science, Jiangnan University, Wuxi, Jiangsu, 214122, China.
| | - Aihui Sun
- Computational Optics Laboratory, School of Science, Jiangnan University, Wuxi, Jiangsu, 214122, China.
| | - Zhilong Jiang
- Computational Optics Laboratory, School of Science, Jiangnan University, Wuxi, Jiangsu, 214122, China.
| | - Cheng Liu
- Computational Optics Laboratory, School of Science, Jiangnan University, Wuxi, Jiangsu, 214122, China.
- Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China
| | - Shouyu Wang
- OptiX+ Laboratory, Wuxi University, Wuxi, Jiangsu, 214105, China
| | - Yan Kong
- Computational Optics Laboratory, School of Science, Jiangnan University, Wuxi, Jiangsu, 214122, China.
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Niu J, Hui Q, Mo W, Yao Q, Gong H, Tian R, Zhu A. A dual functional tunable terahertz metamaterial absorber based on vanadium dioxide. Phys Chem Chem Phys 2024; 26:10633-10640. [PMID: 38511282 DOI: 10.1039/d4cp00081a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
A dual-functional switchable metamaterial absorber (MMA) based on vanadium dioxide (VO2), which achieves flexible switching between broadband absorption and four-band absorption by adjusting the VO2 conductivity, was proposed. The device has a broadband absorption function when VO2 is in the metal phase, and the conductivity is 3 × 105 S m-1. Numerical simulation shows that the absorption rate of the device reaches over 90% in the frequency range of 3.36-6.98 THz. The absorber exhibits polarization insensitivity and wide-angle absorption to transverse electric (TE) and transverse magnetic (TM) waves. When VO2 is in the insulator phase, and the conductivity is 3 × 102 S m-1, the device switches to a narrowband absorber with a band-efficient absorption function. Numerical simulation shows that the device has an absorption rate of 99.7% at 2.39 THz, 98.3% at 2.83 THz, 95.6% at 3.84 THz, and 96.1% at 4.61 THz. It can be used as a sensor with high sensitivity. In addition, to verify the absorption mechanism of the absorber, we introduced impedance matching theory to analyze the device. Finally, the influence of structural parameters on the performance of resonators was investigated. Through the joint action of multi-layer structures, the proposed MMA concentrates broadband and narrowband absorption functions on one device, achieving flexible switching between tasks without changing the structure. The switchable metamaterial absorber designed through simple tuning methods has broad application prospects in stealth technology and thermal emitters. It provides a wide range of ideas for the design of terahertz functional devices.
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Affiliation(s)
- Junhao Niu
- Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of ElectronicTechnology, Guilin 541004, China.
| | - Qiang Hui
- Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of ElectronicTechnology, Guilin 541004, China.
| | - Wei Mo
- Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of ElectronicTechnology, Guilin 541004, China.
| | - Qianyu Yao
- Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of ElectronicTechnology, Guilin 541004, China.
| | - Haozhuo Gong
- Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of ElectronicTechnology, Guilin 541004, China.
| | - Renfang Tian
- Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of ElectronicTechnology, Guilin 541004, China.
| | - Aijun Zhu
- Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of ElectronicTechnology, Guilin 541004, China.
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Li X, Wei W, Yang X. Multi-functional terahertz metasurface for a vortex beam, multi-channel focusing, polarization conversion, and broadband absorption based on vanadium dioxide. APPLIED OPTICS 2024; 63:1695-1701. [PMID: 38437268 DOI: 10.1364/ao.514385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 02/01/2024] [Indexed: 03/06/2024]
Abstract
Although terahertz metasurface devices have been widely studied, thus far, metasurfaces can rarely manipulate both circularly and linearly polarized incident waves. In this paper, taking advantage of the phase transition characteristics of vanadium dioxide (V O 2), a multi-functional terahertz metasurface for a vortex beam, multi-channel focusing, polarization conversion, and broadband absorption is proposed. When V O 2 is in the insulating state, a vortex beam is generated at 1.2 THz when the circularly polarized wave is incident on the metasurface. Meanwhile, the multi-channel focusing is realized at 1.0 THz, and the cross-polarization conversion rate can reach more than 90% at the frequencies of 0.6 THz, 1.1 THz, and 1.6 THz when the y-polarized wave is incident vertically. When V O 2 is in the metallic state, the metasurface achieves close to 95% absorption in the range of 0.8-1.5 THz. The designed metasurface has tunability and multi-functional characteristics, which have potential applications in wireless communication.
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Du Z, He C, Xin J, Song Z. Terahertz dynamic multichannel holograms generated by spin-multiplexing reflective metasurface. OPTICS EXPRESS 2024; 32:248-259. [PMID: 38175052 DOI: 10.1364/oe.510046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 12/07/2023] [Indexed: 01/05/2024]
Abstract
In recent years, metasurfaces have attracted considerable interest for their unprecedented capabilities to manipulate intensity, phase, and polarization of an electromagnetic wave. Although metasurface-based wavefront modulation has achieved numerous successful results, implementation of multifunctional devices in a single metasurface still meet significant challenges. Here, a novel multilayer structure is designed using properties of vanadium dioxide (VO2). Propagation phase and geometric phase are introduced in this structure to achieve multichannel holographic imaging in terahertz band. When the temperature is above 68°C, VO2 becomes a metal and it plays a role in wavefront modulation for terahertz wave. The left-handed channel realizes a hologram letter L and the right-handed channel realizes a hologram letter R. When the temperature is below 68°C, VO2 changes to an insulator, and electromagnetic wave is controlled by gold structures embedded inside a VO2 film. In this case, hologram number 2 is realized in the left-handed channel and hologram number 6 appears in the right-handed channel. Our structure has advantages of low crosstalk, multiple channels, and large bandwidth. This novel design paves a new road for multichannel imaging and information encryption.
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Zhao Q, Qin X, Xu C, Zhou H, Wang BX. Broadband tunable terahertz metamaterial absorber having near-perfect absorbance modulation capability based on a patterned vanadium dioxide circular patch. APPLIED OPTICS 2023; 62:9283-9290. [PMID: 38108699 DOI: 10.1364/ao.499641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 11/08/2023] [Indexed: 12/19/2023]
Abstract
A new tunable broadband terahertz metamaterial absorber has been designed based on patterned vanadium dioxide (V O 2). The absorber consists of three simple layers, the top V O 2 pattern layer, the middle media layer, and the bottom metal layer. Based on phase transition properties of V O 2, the designed device has excellent absorption modulation capability, achieving the functional transition from broadband absorption to near-perfect reflection. When V O 2 is in the metallic state, there are two absorption peaks observed at frequencies of 4.16 and 6.05 THz, exhibiting near-perfect absorption characteristics; the combination of these two absorption peaks gives rise to the broadband phenomenon and the absorption bandwidth, where the absorbance exceeds 90% and spans from 3.40 to 7.00 THz, with a corresponding relative absorption bandwidth of 69.23%. The impedance matching theory, near-field patterns, and surface current distributions are provided to analyze the causes of broadband absorption. Furthermore, the broadband absorption could be completely suppressed when V O 2 presents the dielectric phase, and its absorbance could be dynamically adjusted from 100% to less than 0.70%, thereby achieving near-perfect reflection. Owing to its symmetrical structure, it exhibits excellent performance in different polarization directions and at large incidence angles. Our proposed absorber may have a wide range of promising applications and can be applied in a variety of fields such as communications, imaging, sensing, and security detection.
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Zheng L, Feng R, Shi H, Li X. Tunable Broadband Terahertz Metamaterial Absorber Based on Vanadium Dioxide and Graphene. MICROMACHINES 2023; 14:1715. [PMID: 37763877 PMCID: PMC10537236 DOI: 10.3390/mi14091715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/22/2023] [Accepted: 08/25/2023] [Indexed: 09/29/2023]
Abstract
We propose a dynamically tunable ultra-broadband terahertz metamaterial absorber, which was based on graphene and vanadium oxide (VO2) and numerically demonstrated. The excellent absorption bandwidth almost entirely greater than 90% was as wide as 6.35 THz from 2.30 to 8.65 THz under normal incidence. By changing the conductivity of VO2 from 20 S/m to 3 × 105 S/m, the absorption intensity could be dynamically tuned from 6% to 99%. The physical mechanism of the ultra-wideband absorption is discussed based on the interference cancelation, impedance matching theory, and field distributions, and the influences of the structural parameters on absorption are also discussed. According to the symmetric configuration, the absorption spectra of the considered polarizations were very close to each other, resulting in a polarization-insensitive structure. Such a tunable ultra-broadband absorber may have promising potential in the applications of modulating, cloaking, switching, and imaging technology.
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Affiliation(s)
- Laifang Zheng
- Department of Electrical Engineering, Taiyuan Institute of Technology, Taiyuan 030008, China;
- China Key Laboratory of Micro/Nano Devices and Systems, Ministry of Education, North University of China, Taiyuan 030051, China; (H.S.); (X.L.)
| | - Rui Feng
- China Key Laboratory of Micro/Nano Devices and Systems, Ministry of Education, North University of China, Taiyuan 030051, China; (H.S.); (X.L.)
| | - Huanting Shi
- China Key Laboratory of Micro/Nano Devices and Systems, Ministry of Education, North University of China, Taiyuan 030051, China; (H.S.); (X.L.)
| | - Xuanjing Li
- China Key Laboratory of Micro/Nano Devices and Systems, Ministry of Education, North University of China, Taiyuan 030051, China; (H.S.); (X.L.)
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Zhang X, Wang G, Liu J, Zuo S, Li M, Yang S, Jia Y, Gao Y. Switchable and Tunable Terahertz Metamaterial Based on Vanadium Dioxide and Photosensitive Silicon. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2144. [PMID: 37513155 PMCID: PMC10385666 DOI: 10.3390/nano13142144] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 07/19/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023]
Abstract
A switchable and tunable terahertz (THz) metamaterial based on photosensitive silicon and Vanadium dioxide (VO2) was proposed. By using a finite-difference time-domain (FDTD) method, the transmission and reflective properties of the metamaterial were investigated theoretically. The results imply that the metamaterial can realize a dual electromagnetically induced transparency (EIT) or two narrow-band absorptions depending on the temperature of the VO2. Additionally, the magnitude of the EIT and two narrow-band absorptions can be tuned by varying the conductivity of photosensitive silicon (PSi) via pumping light. Correspondingly, the slow-light effect accompanying the EIT can also be adjusted.
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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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Chen W, Li C, Wang D, Gao S, Zhang C, Guo H, An W, Guo S, Wu G. A dual ultra-broadband switchable high-performance terahertz absorber based on hybrid graphene and vanadium dioxide. Phys Chem Chem Phys 2023. [PMID: 37466116 DOI: 10.1039/d3cp01312j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
A tunable dual broadband switchable terahertz absorber based on vanadium dioxide and graphene is proposed. The tunability of graphene and the phase transition properties of vanadium dioxide are used to switch broadband absorption between low-frequency and high-frequency, as well as the absorption rate tuning function. The simulation results indicate that when vanadium dioxide is in the insulating phase and the graphene Fermi energy is 0.7 eV, the absorber achieves low-frequency broadband absorption within the range of 2.6-4.2 THz with an absorptance greater than 90%; when vanadium dioxide is in the metallic phase and the graphene Fermi energy is 0 eV, the absorber achieves high-frequency broadband absorption within the range of 4.9-10 THz with an absorptance greater than 90%. Furthermore, the absorptance can be tuned by adjusting the conductivity of vanadium dioxide or the Fermi energy of graphene. Due to the central symmetry of the proposed structure, the absorber is completely insensitive to polarization. For TE and TM polarized waves, both low and high-frequency broadband absorption are maintained over a range of incident angles from 0° to 50°. The simple structure, tunable absorption rate, insensitivity to polarization angle and incident angle properties are advantages of our proposed absorber. It has broad application prospects in adjustable filters and electromagnetic shielding.
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Affiliation(s)
- Wenya Chen
- School of Information Science and Engineering, University of Jinan, 250022, China.
- Shandong Provincial Key Laboratory of Network-based Intelligent Computing, Jinan, 250022, China
| | - Chao Li
- School of Information Science and Engineering, University of Jinan, 250022, China.
- Shandong Provincial Key Laboratory of Network-based Intelligent Computing, Jinan, 250022, China
| | - Dong Wang
- School of Information Science and Engineering, University of Jinan, 250022, China.
- Shandong Provincial Key Laboratory of Network-based Intelligent Computing, Jinan, 250022, China
| | - Song Gao
- School of Information Science and Engineering, University of Jinan, 250022, China.
- Shandong Provincial Key Laboratory of Network-based Intelligent Computing, Jinan, 250022, China
| | - Chunwei Zhang
- School of Information Science and Engineering, University of Jinan, 250022, China.
- Shandong Provincial Key Laboratory of Network-based Intelligent Computing, Jinan, 250022, China
| | - Haijun Guo
- School of Information Science and Engineering, University of Jinan, 250022, China.
- Shandong Provincial Key Laboratory of Network-based Intelligent Computing, Jinan, 250022, China
| | - Wei An
- School of Information Science and Engineering, University of Jinan, 250022, China.
- Shandong Provincial Key Laboratory of Network-based Intelligent Computing, Jinan, 250022, China
| | - Shijing Guo
- School of Information Science and Engineering, University of Jinan, 250022, China.
- Shandong Provincial Key Laboratory of Network-based Intelligent Computing, Jinan, 250022, China
| | - Guozheng Wu
- School of Information Science and Engineering, University of Jinan, 250022, China.
- Shandong Provincial Key Laboratory of Network-based Intelligent Computing, Jinan, 250022, China
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Fang J, Zhu W, Cao L, Huang X, Zhang B, He D, Wang S. Hybrid dual-mode tunable polarization conversion metasurface based on graphene and vanadium dioxide. OPTICS EXPRESS 2023; 31:23095-23105. [PMID: 37475402 DOI: 10.1364/oe.494565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 06/14/2023] [Indexed: 07/22/2023]
Abstract
We present and numerically verify a functionally hybrid dual-mode tunable polarization conversion metasurface based on graphene and vanadium dioxide (VO2). The tunable polarization converter consists of two patterned graphene layers separated by grating which is composed of gold and VO2. Due to the existence of phase change material VO2, the polarization conversion mode can be switched flexibly between the transmission and reflection modes. Theoretical calculations show the proposed polarization conversion metasurface can obtain giant asymmetric transmission (AT) at 0.42 and 0.77 THz when VO2 is in the insulating state. Conversely, when VO2 is in the metallic state, the converter switches to the reflection mode, demonstrating broadband polarization conversion for both forward and backward incidences. Furthermore, the conductivity of graphene can be modulated by changing the gate voltage, which allows dynamic control polarization conversion bandwidth of the reflection mode as well as the AT of the transmission mode. The robustness of the metasurface has also been verified, the high polarization conversion efficiency and AT can be maintained over wide incidence angles up to 65° for both the xoz plane and yoz plane. These advantages make the proposed hybrid tunable polarization conversion metasurface a promising candidate for THz radiation switching and modulation.
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Zou Y, Lin H, Tian G, Zhou H, Zhu H, Xiong H, Wang BX. Triple-Band and Ultra-Broadband Switchable Terahertz Meta-Material Absorbers Based on the Hybrid Structures of Vanadium Dioxide and Metallic Patterned Resonators. MATERIALS (BASEL, SWITZERLAND) 2023; 16:4719. [PMID: 37445033 DOI: 10.3390/ma16134719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/21/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023]
Abstract
A bifunctional terahertz meta-material absorber with three layers is designed. The surface of the bifunctional meta-material absorber is a periodically patterned array composed of hybrid structures of vanadium dioxide (VO2) and metallic resonators; the middle layer is a nondestructive TOPAS film, and the bottom layer is a continuous metallic plane. Utilizing the phase-transition property of VO2, the responses of the meta-material absorber could be dynamically switched between triple-band absorption and ultra-broadband absorption. When VO2 is in the metallic state, an ultra-broadband absorption covering the bandwidth of 6.62 THz is achieved over the range from 4.71 THz to 11.33 THz. When VO2 is in the di-electric state, three absorption peaks resonated at 10.57 THz, 12.68 THz, and 13.91 THz. The physical mechanisms of the bifunctional meta-material absorber were explored by analyzing their near-field distributions. The effects of varying structural parameters on triple-band and ultra-broadband absorption were investigated. It is revealed that by optimizing the structure parameters, the number of absorption peaks could be increased for a certain sacrifice of absorption bandwidth. FDTD Solutions and CST Microwave Studio were used to simulate the data of the absorber, and similar results were obtained.
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Affiliation(s)
- Yuke Zou
- School of Science, Jiangnan University, Wuxi 214122, China
| | - Hongyan Lin
- School of Science, Jiangnan University, Wuxi 214122, China
| | - Gaowen Tian
- School of Science, Jiangnan University, Wuxi 214122, China
| | - Haiquan Zhou
- Zhejiang Beyondsun Green Energy Technology Co., Ltd., Huzhou 313008, China
| | - Huaxin Zhu
- School of Science, Jiangnan University, Wuxi 214122, China
| | - Han Xiong
- School of Electrical Engineering, Chongqing University, Chongqing 400044, China
| | - Ben-Xin Wang
- School of Science, Jiangnan University, Wuxi 214122, China
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14
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Kitayama D, Pander A, Hama Y, Takahashi H. Alignment-free twisted-split-ring metasurface on single substrate with 2π phase range for linearly polarized sub-terahertz wave. OPTICS EXPRESS 2023; 31:20769-20786. [PMID: 37381193 DOI: 10.1364/oe.494319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 05/26/2023] [Indexed: 06/30/2023]
Abstract
To achieve high-speed, large-capacity communication, next-generation mobile communication systems will require manipulation of the propagation of sub-terahertz waves in the propagation channel. In this paper, we propose the use of a novel split-ring resonator (SRR) structure as a metasurface unit cell for manipulating the linearly polarized incident and transmission waves used in mobile communication systems. In this SRR structure, the gap is twisted by 90° to efficiently use cross-polarized scattered waves. By changing the twist direction and gap size of the unit cell, 2π phase designability can be achieved, which enables linear polarization conversion efficiencies of -2 dB with a backside polarizer and -0.2 dB with two polarizers. In addition, a complementary pattern of the unit cell was fabricated, and a measured conversion efficiency of more than -1 dB at the peak with only the backside polarizer on a single substrate was verified. In the proposed structure, the 2π phase designability and efficiency gain are obtained independently by the unit cell and polarizer, respectively, thus enabling alignment-free characteristics, which are highly advantageous from an industrial viewpoint. Metasurface lenses with binary phase profiles of 0 and π were fabricated using the proposed structure with a backside polarizer on a single substrate. The lenses' focusing, deflection, and collimation operations were experimentally verified with a lens gain of 20.8 dB, which agreed well with our calculated results. Our metasurface lens has the great advantages of easy fabrication and implementation, and it has the potential to enable dynamic control by combining it with active devices because of the simple design methodology, which entails only changing the twist direction and the gap's capacitance component.
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15
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Jalal A, Khan MI, Qasim M, Hu B. Multifunctional and switchable metamaterial for terahertz polarization modulation in the reflection mode. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2023; 40:1183-1190. [PMID: 37706771 DOI: 10.1364/josaa.486473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 05/07/2023] [Indexed: 09/15/2023]
Abstract
In this paper, a broadband multi-layered active metamaterial design is investigated, which can achieve a high polarization conversion efficiency over a wide band of frequencies in the terahertz regime. The design can be switched to an efficient metamaterial absorber using the phase transition property of vanadium dioxide (V O 2). Additionally, the designed structure can convert the linear polarization of the incoming wavefronts to its cross-polarization and linear polarization to circular polarization in the reflection mode. The broadband characteristic is achieved due to the strong anisotropic behavior of the metasurface. The structure is robust to a wide range of incident angles as well. The proposed switchable multifunctional design can contribute to the development of active plasmonic polarization devices and metamaterial absorbers.
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16
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Liu H, Chen W, Ma J, Zhang SY, He HL, Fan YX, Tao ZY. Active control of terahertz waves based on hybrid VO 2 periodic corrugated waveguides. OPTICS EXPRESS 2023; 31:16303-16314. [PMID: 37157712 DOI: 10.1364/oe.486371] [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
We describe a method for the active control of terahertz (THz) waves using hybrid vanadium dioxide (VO2) periodic corrugated waveguide. Unlike liquid crystals, graphene and semiconductors and other active materials, VO2 exhibits a unique insulator-metal transition characteristic by the electric fields, optical, and thermal pumps, resulting in five orders of magnitude changes in its conductivity. Our waveguide consists of two gold coated plates with the VO2-embedded periodic grooves, which are placed in parallel with the grooves face to face. Simulations show that this waveguide can realize mode switching by changing the conductivity of the embedded VO2 pads, whose mechanism is attributed to the local resonance induced by defect mode. Such a VO2-embedded hybrid THz waveguide is favorable in practical applications such as THz modulators, sensors and optical switches, and provides an innovative technique for manipulating THz waves.
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17
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Konnikova MR, Khomenko MD, Tverjanovich AS, Bereznev S, Mankova AA, Parashchuk OD, Vasilevsky IS, Ozheredov IA, Shkurinov AP, Bychkov EA. GeTe 2 Phase Change Material for Terahertz Devices with Reconfigurable Functionalities Using Optical Activation. ACS APPLIED MATERIALS & INTERFACES 2023; 15:9638-9648. [PMID: 36780579 DOI: 10.1021/acsami.2c21678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The phenomenon of phase change transition has been a fascinating research subject over decades due to a possibility of dynamically controlled materials properties, allowing the creation of optical devices with unique features. The present paper unravels the optical characteristics and terahertz (THz) dielectric permittivity of a novel phase change material (PCM), GeTe2, prepared by pulsed laser deposition (PLD) and their remarkable contrast in crystalline and amorphous states, in particular, a difference of 7 orders of magnitude in conductivity. The THz spectra were analyzed using the harmonic oscillator and Drude term. Using GeTe2 PLD films, we designed and prepared a THz metasurface in the form of periodic structure and revealed a possibility of tuning the THz resonance either by a thermal control or light-induced crystallization response, thus achieving the dynamic and tunable functionality of the metastructure. We propose controlling the state of metasurface by observing the intensity characteristics of the Raman peak of 155 cm-1. Density functional theory (DFT) modeling demonstrates that in the process of crystallization the mode intensity of 155 cm-1 assigned to Te-Te stretching in amorphous chain fragments decreases and disappears at full crystallization.
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Affiliation(s)
- Maria R Konnikova
- Faculty of Physics, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia
- ILIT RAS-Branch of the FSRC "Crystallography and Photonics", RAS, 140700 Shatura, Moscow Region, Russia
- Laboratory of Biophotonics, National Research Tomsk State University, 634050, Tomsk, Russia
| | - Maxim D Khomenko
- ILIT RAS-Branch of the FSRC "Crystallography and Photonics", RAS, 140700 Shatura, Moscow Region, Russia
| | - Andrey S Tverjanovich
- Institute of Chemistry, St. Petersburg State University, 198504 St. Petersburg, Russia
| | - Sergei Bereznev
- Department of Materials and Environmental Technology, Tallinn University of Technology, 19086 Tallinn, Estonia
| | - Anna A Mankova
- Faculty of Physics, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia
| | - Olga D Parashchuk
- Faculty of Physics, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia
| | - Ivan S Vasilevsky
- National Research Nuclear University MEPhI, Kashirskoe sh. 31, 115409 Moscow, Russia
| | - Ilya A Ozheredov
- Faculty of Physics, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia
- ILIT RAS-Branch of the FSRC "Crystallography and Photonics", RAS, 140700 Shatura, Moscow Region, Russia
| | - Alexander P Shkurinov
- Faculty of Physics, Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia
- Laboratory of Biophotonics, National Research Tomsk State University, 634050, Tomsk, Russia
| | - Eugene A Bychkov
- ILIT RAS-Branch of the FSRC "Crystallography and Photonics", RAS, 140700 Shatura, Moscow Region, Russia
- Laboratoire de Physico-Chimie de l'Atmosphère, Université du Littoral Côte d'Opale, 59140 Dunkerque, France
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18
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Zhang YG, Zhang R, Liang LJ, Yao HY, Yan X, Huang CC, Ying KH. Multifunctional terahertz absorber based on the Dirac semimetal and vanadium dioxide. APPLIED OPTICS 2023; 62:813-819. [PMID: 36821288 DOI: 10.1364/ao.478846] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 12/07/2022] [Indexed: 06/18/2023]
Abstract
In this paper, a multifunctional terahertz (THz) absorber based on Dirac semimetal and vanadium dioxide (V O 2) is proposed. By modulating the temperature of V O 2, the absorber can be switched between the narrow band and wide band. When V O 2 is in the metallic state, the absorber has a broadband absorption effect with a bandwidth of approximately 4 THz. It has the advantages of insensitivity to polarization and wide-angle absorption. When V O 2 is in the insulating state, the absorber has two absorption peaks with absorptivity exceeding 90% and sensitivities of 297.7 and 402 GHz/RIU, and thus can be used as a highly sensitive sensor for cell detection. When the Fermi level of the Dirac semimetal is changed, the absorption characteristics can be modulated. The absorber has broad application prospects in multifunctional modulated devices.
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19
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Zhuang L, Zhang W, Liu J, Chao M, Liu Q, Cheng B, Xu Y, Song G. Switchable trifunctional terahertz absorber for both broadband and narrowband operations. OPTICS EXPRESS 2022; 30:45848-45861. [PMID: 36522980 DOI: 10.1364/oe.476527] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 11/13/2022] [Indexed: 06/17/2023]
Abstract
In this paper, we proposed a multilayer terahertz absorber composed of hybrid graphene and vanadium dioxide (VO2). Based on electrical controlling of graphene and thermal tuning of VO2, three different switchable absorption states are achieved in one structure. When VO2 is in the metal phase and the Fermi level of graphene is set as 0eV, high-frequency broadband (bandwidth, 5.45THz) absorption from 4.5 to 9.95THz is demonstrated. While VO2 is switched to the insulator state, absorption states depend on the Fermi energy of graphene. As the Fermi level changes from 1eV to 0eV, the absorption can be switched from low-frequency broadband (bandwidth, 2.86THz) to dual-frequency absorption. The effect of geometric parameters and fabrication tolerance on the robustness of the absorption properties is explored. The proposed absorber has three switchable states through modulation of graphene and VO2, which is expected to realize potential applications in modulating, filtering, detecting, and other fields.
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20
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Zhang X, Zhang K, Chen B, Guo L, Kong W. Switchable multi-functional broadband polarization converter in terahertz band. OPTICS EXPRESS 2022; 30:41969-41979. [PMID: 36366660 DOI: 10.1364/oe.474142] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 10/18/2022] [Indexed: 06/16/2023]
Abstract
In this work, we propose a multi-functional broadband terahertz polarization converter based on graphene-VO2 hybrid metamaterial, which can switch between transmissive linear-to-linear conversion and reflective linear-to-circular conversion. The function of the metamaterial can be controlled by both the temperature and the Fermi energy of the graphene. At 298K, the metamaterial converts the y-polarized wave into x-polarized wave in 0.39-1.22THz. In the meanwhile, changing the Fermi energy of graphene, the converted polarization angle can be tuned from 90° to 45°. Increasing the temperature to 358K, the incident linearly polarized wave is reflected into circularly polarized wave. On this condition, tuning the Fermi energy, the metamaterial can separately convert the linear polarization wave into left-circularly polarized wave in 1.57-2.74THz and right-circularly polarized wave in 1.13-1.59THz. Such a switchable multi-functional broadband polarization converter may achieve potential applications in compact terahertz devices and integrated terahertz circuits.
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21
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Zeng D, Zong S, Liu G, Yuan W, Liu X, Liu Z. Dynamically electrical/thermal-tunable perfect absorber for a high-performance terahertz modulation. OPTICS EXPRESS 2022; 30:39736-39746. [PMID: 36298919 DOI: 10.1364/oe.474970] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 09/28/2022] [Indexed: 06/16/2023]
Abstract
We present a high-performance functional perfect absorber in a wide range of terahertz (THz) wave based on a hybrid structure of graphene and vanadium dioxide (VO2) resonators. Dynamically electrical and thermal tunable absorption is achieved due to the management on the resonant properties via the external surroundings. Multifunctional manipulations can be further realized within such absorber platform. For instance, a wide-frequency terahertz perfect absorber with the operation frequency range covering from 1.594 THz to 3.272 THz can be realized when the conductivity of VO2 is set to 100000 S/m (metal phase) and the Fermi level of graphene is 0.01 eV. The absorption can be dynamically changed from 0 to 99.98% and in verse by adjusting the conductivity of VO2. The impedance matching theory is introduced to analyze and elucidate the wideband absorption rate. In addition, the absorber can be changed from wideband absorption to dual-band absorption by adjusting the Fermi level of graphene from 0.01 eV to 0.7 eV when the conductivity of VO2 is fixed at 100000 S/m. Besides, the analysis of the chiral characteristics of the helical structure shows that the extinction cross-section has a circular dichroic response under the excitation of two different circularly polarized lights (CPL). Our study proposes approaches to manipulate the wide-band terahertz wave with multiple ways, paving the way for the development of technologies in the fields of switches, modulators, and imaging devices.
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22
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Mallick S, Jana A, Acharyya N, Roy Chowdhury D. Simultaneous excitations of odd and even order resonances in plasmonic metasurfaces for an orthogonal terahertz probe. APPLIED OPTICS 2022; 61:7435-7442. [PMID: 36256046 DOI: 10.1364/ao.465207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 08/09/2022] [Indexed: 06/16/2023]
Abstract
Most of the compelling phenomena pertaining to plasmonic metamaterials revolve around the associated odd and even order resonances. However, excitation of odd and even order modes is polarization sensitive, particularly in the case of well-accepted split-ring resonator based terahertz (THz) plasmonic metasurfaces. Such a drawback limits the practical applications of plasmonic metasurfaces across the electromagnetic spectrum. In this context, we experimentally demonstrate multi-split-ring resonator based THz metasurfaces capable of simultaneously sustaining odd and even order resonances when the polarization of the probe beam is altered through 90°. We believe this work should be beneficial in realizing polarization-independent switches and frequency selective surfaces.
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23
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Li W, Xu M, Xu HX, Wang X, Huang W. Metamaterial Absorbers: From Tunable Surface to Structural Transformation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2202509. [PMID: 35604541 DOI: 10.1002/adma.202202509] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/28/2022] [Indexed: 06/15/2023]
Abstract
Since the first demonstration, remarkable progress has been made in the theoretical analysis, structural design, numerical simulation, and potential applications of metamaterial absorbers (MAs). With the continuous advancement of novel materials and creative designs, the absorption of MAs is significantly improved over a wide frequency spectrum from microwaves to the optical regime. Further, the integration of active elements into the MA design allows the dynamical manipulation of electromagnetic waves, opening a new platform to push breakthroughs in metadevices. In the last several years, numerous efforts have been devoted to exploring innovative approaches for incorporating tunability to MAs, which is highly desirable because of the progressively increasing demand on designing versatile metadevices. Here, a comprehensive and systematical overview of active MAs with adaptive and on-demand manner is presented, highlighting innovative materials and unique strategies to precisely control the electromagnetic response. In addition to the mainstream method by manipulating periodic patterns, two additional approaches, including tailoring dielectric spacer and transforming overall structure are called back. Following this, key parameters, such as operating frequency, relative tuning range, and switching speed are summarized and compared to guide for optimum design. Finally, potential opportunities in the development of active MAs are discussed.
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Affiliation(s)
- Weiwei Li
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, P. R. China
- Shaanxi Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, P. R. China
| | - Manzhang Xu
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, P. R. China
- Shaanxi Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, P. R. China
| | - He-Xiu Xu
- Air and Missile Defense College, Air Force Engineering University, Xi'an, 710051, P. R. China
| | - Xuewen Wang
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, P. R. China
- Shaanxi Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, P. R. China
- MIIT Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, P. R. China
| | - Wei Huang
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, P. R. China
- Shaanxi Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, P. R. China
- MIIT Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, P. R. China
- State Key Laboratory of Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, Nanjing, 210023, P. R. China
- Key Laboratory of Flexible Electronics(KLoFE)and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), Nanjing, 211800, P. R. China
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24
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Wu Q, Fan W, Qin C. Generation and Superposition of Perfect Vortex Beams in Terahertz Region via Single-Layer All-Dielectric Metasurface. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:3010. [PMID: 36080049 PMCID: PMC9457957 DOI: 10.3390/nano12173010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 06/15/2023]
Abstract
Terahertz (THz) orbital angular momentum (OAM) technology provides promising applications in future wireless communication with large bandwidth and high capacity. However, the ring radius of the conventional THz vortex beam is related to the topological charge, limiting the co-propagation of multiple OAM modes in the THz communication systems. Although the perfect vortex beam (PVB) based on traditional methods can solve this problem, they are usually bulky and unstable. Here, we demonstrate two PVB generators based on a single all-dielectric metasurface to obtain polarization-independent PVB and spin multiplexed PVB, respectively. The former regulates the propagation phase by using isotropic unit cells; the latter simultaneously manipulates the propagation and geometric phase to achieve the spin-decoupled phase control by arranging anisotropic unit cells. In addition, we also demonstrate the stable generation of a perfect Poincaré beam with arbitrary polarization and phase distribution on a hybrid-order Poincaré Sphere via a spin-decoupled metasurface, which is achieved by the linear superposition of two PVBs with orthogonal circular polarizations. The proposed scheme provides a compact and efficient platform for the generation and superposition of PVBs in THz region, and will speed up the progress of THz communication systems, complex light field generation, and quantum information sciences.
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Affiliation(s)
- Qi Wu
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
- School of Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenhui Fan
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
- School of Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
| | - Chong Qin
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
- School of Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
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25
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Programmable VO2 metasurface for terahertz wave beam steering. iScience 2022; 25:104824. [PMID: 35992076 PMCID: PMC9382261 DOI: 10.1016/j.isci.2022.104824] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 06/29/2022] [Accepted: 07/19/2022] [Indexed: 12/02/2022] Open
Abstract
Programmable vanadium dioxide (VO2) metasurface is proposed at THz frequencies. The insulating and metallic states of VO2 can be switched via external electrical stimulation, resulting in the dynamical modulation of electromagnetic response. The voltages of different columns of the metasurface can be controlled by the field-programmable gate array, and thus the phase gradients are realized for THz beam steering. In 1-bit coding, we design periodic and nonperiodic 24 × 24 coding sequences, and achieve wide-angle beam scanning with the deflection angles from −60° to +60°. In 2-bit coding, we use two different meta-atoms to design 18 × 18 coding sequences. Compared with 1-bit coding, 2-bit coding has more degree of freedom to control the optical phase, and 3 dB diffraction efficiency is improved by generating a single deflection angle. The proposed programmable metasurfaces provide a promising platform for manipulating electromagnetic wave in 6G wireless communication. The reversible phase-transition material VO2 is integrated into the metasurface Programmable VO2 metasurfaces are proposed to achieve THz beam steering Wide-angle beam scanning from −60° to +60° is realized in the digitalized metasurface
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Switchable Multifunctional Terahertz Metamaterials Based on the Phase-Transition Properties of Vanadium Dioxide. MICROMACHINES 2022; 13:mi13071013. [PMID: 35888830 PMCID: PMC9318613 DOI: 10.3390/mi13071013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 06/19/2022] [Accepted: 06/24/2022] [Indexed: 11/17/2022]
Abstract
Currently, terahertz metamaterials are studied in many fields, but it is a major challenge for a metamaterial structure to perform multiple functions. This paper proposes and studies a switchable multifunctional multilayer terahertz metamaterial. Using the phase-transition properties of vanadium dioxide (VO2), metamaterials can be controlled to switch transmission and reflection. Transmissive metamaterials can produce an electromagnetically induced transparency-like (EIT-like) effect that can be turned on or off according to different polarization angles. The reflective metamaterial is divided into I-side and II-side by the middle continuous VO2 layer. The I-side metamaterials can realize linear-to-circular polarization conversion from 0.444 to 0.751 THz when the incident angle of the y-polarized wave is less than 30°. The II-side metamaterials can realize linear-to-linear polarization conversion from 0.668 to 0.942 THz when the incident angle of the y-polarized wave is less than 25°. Various functions can be switched freely by changing the conductivity of VO2 and the incident surface. This enables metamaterials to be used as highly sensitive sensors, optical switches, and polarization converters, which provides a new strategy for the design of composite functional metamaterials.
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Switchable Terahertz Absorber from Single Broadband to Dual Broadband Based on Graphene and Vanadium Dioxide. NANOMATERIALS 2022; 12:nano12132172. [PMID: 35808007 PMCID: PMC9268442 DOI: 10.3390/nano12132172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 06/16/2022] [Accepted: 06/22/2022] [Indexed: 11/17/2022]
Abstract
A multifunctional switchable terahertz (THz) absorber based on graphene and vanadium dioxide (VO2) is presented. The properties of the absorber are studied theoretically by the finite-difference time-domain (FDTD) method. The results illustrate that the structure switches between the single-broadband or double-broadband absorption depending on the temperature of VO2. Moreover, the amplitude of the absorptivity can be adjusted by changing the Fermi energy level (EF) of graphene or the conductivity of VO2 separately. Via impedance matching theory, the physical mechanism of the absorber is researched. Furthermore, the effects of incidence angle on absorption have also been studied. It is found that the absorber is insensitive to the polarization of electromagnetic waves.
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28
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Feng H, Zhang Z, Zhang J, Fang D, Wang J, Liu C, Wu T, Wang G, Wang L, Ran L, Gao Y. Tunable Dual-Broadband Terahertz Absorber with Vanadium Dioxide Metamaterial. NANOMATERIALS 2022; 12:nano12101731. [PMID: 35630953 PMCID: PMC9143179 DOI: 10.3390/nano12101731] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 05/14/2022] [Accepted: 05/17/2022] [Indexed: 11/24/2022]
Abstract
A dual broadband terahertz bifunction absorber that can be actively tuned is proposed. The optical properties of the absorber were simulated and numerically calculated using the finite-difference time-domain (FDTD) method. The results show that when the conductivity of vanadium dioxide is less than σ0=8.5×103 S/m, the absorptance can be continuously adjusted between 2% and 100%. At vanadium dioxide conductivity greater than σ0=8.5×103 S/m, the absorption bandwidth of the absorber can be switched from 3.4 THz and 3.06 THz to 2.83 THz and none, respectively, and the absorptance remains above 90%. This achieves perfect modulation of the absorptance and absorption bandwidth. The physical mechanism of dual-broadband absorptions and perfect absorption is elucidated by impedance matching theory and electric field distribution. In addition, it also has the advantage of being polarization insensitive and maintaining stable absorption at wide angles of oblique incidence. The absorber may have applications in emerging fields such as modulators, stealth and light-guided optical switches.
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Affiliation(s)
- Hengli Feng
- School of Electronic Engineering, Heilongjiang University, Harbin 150080, China; (H.F.); (Z.Z.); (J.Z.); (D.F.); (J.W.); (C.L.); (T.W.); (G.W.); (L.W.); (L.R.)
| | - Zuoxin Zhang
- School of Electronic Engineering, Heilongjiang University, Harbin 150080, China; (H.F.); (Z.Z.); (J.Z.); (D.F.); (J.W.); (C.L.); (T.W.); (G.W.); (L.W.); (L.R.)
| | - Jingyu Zhang
- School of Electronic Engineering, Heilongjiang University, Harbin 150080, China; (H.F.); (Z.Z.); (J.Z.); (D.F.); (J.W.); (C.L.); (T.W.); (G.W.); (L.W.); (L.R.)
| | - Dongchao Fang
- School of Electronic Engineering, Heilongjiang University, Harbin 150080, China; (H.F.); (Z.Z.); (J.Z.); (D.F.); (J.W.); (C.L.); (T.W.); (G.W.); (L.W.); (L.R.)
| | - Jincheng Wang
- School of Electronic Engineering, Heilongjiang University, Harbin 150080, China; (H.F.); (Z.Z.); (J.Z.); (D.F.); (J.W.); (C.L.); (T.W.); (G.W.); (L.W.); (L.R.)
| | - Chang Liu
- School of Electronic Engineering, Heilongjiang University, Harbin 150080, China; (H.F.); (Z.Z.); (J.Z.); (D.F.); (J.W.); (C.L.); (T.W.); (G.W.); (L.W.); (L.R.)
| | - Tong Wu
- School of Electronic Engineering, Heilongjiang University, Harbin 150080, China; (H.F.); (Z.Z.); (J.Z.); (D.F.); (J.W.); (C.L.); (T.W.); (G.W.); (L.W.); (L.R.)
| | - Guan Wang
- School of Electronic Engineering, Heilongjiang University, Harbin 150080, China; (H.F.); (Z.Z.); (J.Z.); (D.F.); (J.W.); (C.L.); (T.W.); (G.W.); (L.W.); (L.R.)
| | - Lehui Wang
- School of Electronic Engineering, Heilongjiang University, Harbin 150080, China; (H.F.); (Z.Z.); (J.Z.); (D.F.); (J.W.); (C.L.); (T.W.); (G.W.); (L.W.); (L.R.)
| | - Lingling Ran
- School of Electronic Engineering, Heilongjiang University, Harbin 150080, China; (H.F.); (Z.Z.); (J.Z.); (D.F.); (J.W.); (C.L.); (T.W.); (G.W.); (L.W.); (L.R.)
| | - Yang Gao
- School of Electronic Engineering, Heilongjiang University, Harbin 150080, China; (H.F.); (Z.Z.); (J.Z.); (D.F.); (J.W.); (C.L.); (T.W.); (G.W.); (L.W.); (L.R.)
- Heilongjiang Provincial Key Laboratory of Metamaterials Physics and Device, School of Electronic Engineering, Heilongjiang University, Harbin 150080, China
- Correspondence:
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29
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Boyce A, Stewart JW, Avila J, Shen Q, Zhang S, Wheeler VD, Mikkelsen MH. Actively Tunable Metasurfaces via Plasmonic Nanogap Cavities with Sub-10-nm VO 2 Films. NANO LETTERS 2022; 22:3525-3531. [PMID: 35472261 PMCID: PMC9101075 DOI: 10.1021/acs.nanolett.1c04175] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 03/20/2022] [Indexed: 05/31/2023]
Abstract
Actively tunable optical materials integrated with engineered subwavelength structures could enable novel optoelectronic devices, including reconfigurable light sources and tunable on-chip spectral filters. The phase-change material vanadium dioxide (VO2) provides a promising solid-state solution for dynamic tuning; however, previous demonstrations have been limited to thicker and often rough VO2 films or require a lattice-matched substrate for growth. Here, sub-10-nm-thick VO2 films are realized by atomic layer deposition (ALD) and integrated with plasmonic nanogap cavities to demonstrate tunable, spectrally selective absorption across 1200 nm in the near-infrared (NIR). Upon inducing the phase transition via heating, the absorption resonance is blue-shifted by as much as 60 nm. This process is reversible upon cooling and repeatable over more than ten temperature cycles. Dynamic, ultrathin VO2 films deposited by ALD, as demonstrated here, open up new potential architectures and applications where VO2 can be utilized to provide reconfigurability including three-dimensional, flexible and large-area structures.
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Affiliation(s)
- Andrew
M. Boyce
- Department
of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Jon W. Stewart
- Department
of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Jason Avila
- U.S.
Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Qixin Shen
- Department
of Physics, Duke University, Durham, North Carolina 27708, United States
| | - Siyuan Zhang
- Department
of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, United States
| | | | - Maiken H. Mikkelsen
- Department
of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, United States
- Department
of Physics, Duke University, Durham, North Carolina 27708, United States
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30
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Zhang P, Chen G, Hou Z, Zhang Y, Shen J, Li C, Zhao M, Gao Z, Li Z, Tang T. Ultra-Broadband Tunable Terahertz Metamaterial Absorber Based on Double-Layer Vanadium Dioxide Square Ring Arrays. MICROMACHINES 2022; 13:mi13050669. [PMID: 35630136 PMCID: PMC9145387 DOI: 10.3390/mi13050669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/19/2022] [Accepted: 04/22/2022] [Indexed: 12/10/2022]
Abstract
Based on the phase transition of vanadium dioxide(VO2), an ultra-broadband tunable terahertz metamaterial absorber is proposed. The absorber consists of bilayer VO2 square ring arrays with different sizes, which are completely wrapped in Topas and placed on gold substrate. The simulation results show that the absorption greater than 90% has frequencies ranging from 1.63 THz to 12.39 THz, which provides an absorption frequency bandwidth of 10.76 THz, and a relative bandwidth of 153.5%. By changing the electrical conductivity of VO2, the absorption intensity can be dynamically adjusted between 4.4% and 99.9%. The physical mechanism of complete absorption is elucidated by the impedance matching theory and field distribution. The proposed absorber has demonstrated its properties of polarization insensitivity and wide-angle absorption, and therefore has a variety of application prospects in the terahertz range, such as stealth, modulation, and sensing.
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Affiliation(s)
- Pengyu Zhang
- School of Information and Communication Engineering, Hainan University, Haikou 570228, China; (P.Z.); (G.C.); (Z.H.); (Y.Z.); (M.Z.); (Z.G.); (Z.L.)
- State Key Laboratory of Marine Resources Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Guoquan Chen
- School of Information and Communication Engineering, Hainan University, Haikou 570228, China; (P.Z.); (G.C.); (Z.H.); (Y.Z.); (M.Z.); (Z.G.); (Z.L.)
- State Key Laboratory of Marine Resources Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Zheyu Hou
- School of Information and Communication Engineering, Hainan University, Haikou 570228, China; (P.Z.); (G.C.); (Z.H.); (Y.Z.); (M.Z.); (Z.G.); (Z.L.)
- State Key Laboratory of Marine Resources Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Yizhuo Zhang
- School of Information and Communication Engineering, Hainan University, Haikou 570228, China; (P.Z.); (G.C.); (Z.H.); (Y.Z.); (M.Z.); (Z.G.); (Z.L.)
- State Key Laboratory of Marine Resources Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Jian Shen
- School of Information and Communication Engineering, Hainan University, Haikou 570228, China; (P.Z.); (G.C.); (Z.H.); (Y.Z.); (M.Z.); (Z.G.); (Z.L.)
- State Key Laboratory of Marine Resources Utilization in South China Sea, Hainan University, Haikou 570228, China
- Correspondence: (J.S.); (C.L.)
| | - Chaoyang Li
- School of Information and Communication Engineering, Hainan University, Haikou 570228, China; (P.Z.); (G.C.); (Z.H.); (Y.Z.); (M.Z.); (Z.G.); (Z.L.)
- State Key Laboratory of Marine Resources Utilization in South China Sea, Hainan University, Haikou 570228, China
- Correspondence: (J.S.); (C.L.)
| | - Maolin Zhao
- School of Information and Communication Engineering, Hainan University, Haikou 570228, China; (P.Z.); (G.C.); (Z.H.); (Y.Z.); (M.Z.); (Z.G.); (Z.L.)
- State Key Laboratory of Marine Resources Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Zhuozhen Gao
- School of Information and Communication Engineering, Hainan University, Haikou 570228, China; (P.Z.); (G.C.); (Z.H.); (Y.Z.); (M.Z.); (Z.G.); (Z.L.)
- State Key Laboratory of Marine Resources Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Zhiqi Li
- School of Information and Communication Engineering, Hainan University, Haikou 570228, China; (P.Z.); (G.C.); (Z.H.); (Y.Z.); (M.Z.); (Z.G.); (Z.L.)
- State Key Laboratory of Marine Resources Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Tingting Tang
- Information Materials and Device Applications Key Laboratory of Sichuan Provincial Universities, Chengdu University of Information Technology, Chengdu 610225, China;
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31
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Wang X, Ma C, Xiao L, Li X, Yu J, Xiao B. Dynamically tunable broadband absorber/reflector based on graphene and VO 2 metamaterials. APPLIED OPTICS 2022; 61:1646-1651. [PMID: 35297840 DOI: 10.1364/ao.448619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
We propose a difunctional tunable broadband absorber/reflector consisting of a periodic cross-shaped graphene array and a vanadium dioxide (VO2) layer. When VO2 reflects the properties of metal, the proposed dual-function device is used as a reflector; when VO2 reflects the nature of the dielectric, the difunctional device will be used as an absorber. The simulation results indicate that more than 90% absorption bandwidth can be available in the absorber in the frequency range of 56.1-59.0 THz, up to 100%. Moreover, over 80% absorption can be achieved over the frequency range of 88.5 to 90.2 THz. In addition, the bandwidth and absorption of the metamaterial absorber can be dynamically changed because of the Fermi energy level in graphene and the temperature tunability of VO2. The proposed device can be applied to manufacturing infrared spectrophotometers, on-dispersive infrared photometers, and Fourier transform infrared spectrometers. Therefore, it has potential application in the field of environmental monitoring.
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32
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Yang F, Pitchappa P, Wang N. Terahertz Reconfigurable Intelligent Surfaces (RISs) for 6G Communication Links. MICROMACHINES 2022; 13:285. [PMID: 35208409 PMCID: PMC8879315 DOI: 10.3390/mi13020285] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/02/2022] [Accepted: 02/04/2022] [Indexed: 02/04/2023]
Abstract
The forthcoming sixth generation (6G) communication network is envisioned to provide ultra-fast data transmission and ubiquitous wireless connectivity. The terahertz (THz) spectrum, with higher frequency and wider bandwidth, offers great potential for 6G wireless technologies. However, the THz links suffers from high loss and line-of-sight connectivity. To overcome these challenges, a cost-effective method to dynamically optimize the transmission path using reconfigurable intelligent surfaces (RISs) is widely proposed. RIS is constructed by embedding active elements into passive metasurfaces, which is an artificially designed periodic structure. However, the active elements (e.g., PIN diodes) used for 5G RIS are impractical for 6G RIS due to the cutoff frequency limitation and higher loss at THz frequencies. As such, various tuning elements have been explored to fill this THz gap between radio waves and infrared light. The focus of this review is on THz RISs with the potential to assist 6G communication functionalities including pixel-level amplitude modulation and dynamic beam manipulation. By reviewing a wide range of tuning mechanisms, including electronic approaches (complementary metal-oxide-semiconductor (CMOS) transistors, Schottky diodes, high electron mobility transistors (HEMTs), and graphene), optical approaches (photoactive semiconductor materials), phase-change materials (vanadium dioxide, chalcogenides, and liquid crystals), as well as microelectromechanical systems (MEMS), this review summarizes recent developments in THz RISs in support of 6G communication links and discusses future research directions in this field.
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Affiliation(s)
| | - Prakash Pitchappa
- Institute of Microelectronics, Agency for Science, Technology and Research, Singapore 138634, Singapore;
| | - Nan Wang
- Institute of Microelectronics, Agency for Science, Technology and Research, Singapore 138634, Singapore;
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Analysis of Asymmetry in Active Split-Ring Resonators to Design Circulating-Current Eigenmode: Demonstration of Beamsteering and Focal-Length Control toward Reconfigurable Intelligent Surface. SENSORS 2022; 22:s22020681. [PMID: 35062642 PMCID: PMC8779269 DOI: 10.3390/s22020681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/11/2022] [Accepted: 01/13/2022] [Indexed: 11/16/2022]
Abstract
In this work, toward an intelligent radio environment for 5G/6G, design methodologies of active split-ring resonators (SRRs) for more efficient dynamic control of metasurfaces are investigated. The relationship between the excitation of circulating-current eigenmode and the asymmetric structure of SRRs is numerically analyzed, and it is clarified that the excitation of the circulating-current mode is difficult when the level of asymmetry of the current path is decreased by the addition of large capacitance such as from semiconductor-based devices. To avoid change in the asymmetry, we incorporated an additional gap (slit) in the SRRs, which enabled us to excite the circulating-current mode even when a large capacitance was implemented. Prototype devices were fabricated according to this design methodology, and by the control of the intensity/phase distribution, the variable focal-length and beamsteering capabilities of the transmitted waves were demonstrated, indicating the high effectiveness of the design. The presented design methodology can be applied not only to the demonstrated case of discrete varactors, but also to various other active metamaterials, such as semiconductor-integrated types for operating in the millimeter and submillimeter frequency bands as potential candidates for future 6G systems.
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34
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Gandhi C, Babu PR, Senthilnathan K. Ultra-thin polarization independent broadband terahertz metamaterial absorber. FRONTIERS OF OPTOELECTRONICS 2021; 14:288-297. [PMID: 36637732 PMCID: PMC9743832 DOI: 10.1007/s12200-021-1223-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 06/16/2021] [Indexed: 06/14/2023]
Abstract
In this work, we present the design of a polarization independent broadband absorber in the terahertz (THz) frequency range using a metasurface resonator. The absorber comprises of three layers, of which, the top layer is made of a vanadium dioxide (VO2) resonator with an electrical conductivity of σ = 200000 S/m; the bottom layer consists of a planar layer made of gold metal, and a dielectric layer is sandwiched between these two layers. The optimized absorber exhibits absorption greater than 90% from 2.54-5.54 THz. Thus, the corresponding bandwidth of the designed absorber is 3 THz. Further, the thermal tunable absorption and reflection spectra have been analyzed by varying the electrical conductivity of VO2. The impact of the various geometrical parameters on the absorption characteristics has also been assessed. The physics of generation of broadband absorption of the proposed device has been explored using field analysis. Finally, the absorption characteristics of the unit cell has been studied for various incident and polarization angles.
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Affiliation(s)
- C Gandhi
- Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, 632014, India
| | - P Ramesh Babu
- Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, 632014, India
| | - K Senthilnathan
- Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, 632014, India.
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35
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Zhang K, Xia F, Li S, Liu Y, Kong W. Actively tunable multi-band terahertz perfect absorber due to the hybrid strong coupling in the multilayer structure. OPTICS EXPRESS 2021; 29:28619-28630. [PMID: 34614988 DOI: 10.1364/oe.434714] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
In this work, we propose a multi-band terahertz perfect absorber employing the topological photonic crystal combined with VO2 and graphene. The hybrid strong coupling among the topological photonic state, the Tamm plasmon polaritons excited around the interfaces of VO2 and graphene results in the three perfect absorption bands. Benefiting from the reversible insulator-metal phase transition of VO2 and the tunable Fermi level of graphene, it can actively switch among no absorption, single-band, dual-band and multi-band absorptions around 1THz, with the absorption frequencies tunable as well. Besides, the absorption bands are sensitive to the incident angle in almost the same dispersion rate, with high absorptions in a large angle range. Moreover, the splitting frequencies between the adjacent absorption peaks strongly depend on the pair number of the alternating multilayers. Apart from the three absorption bands, there are still many absorption peaks in the large frequency range resulting from the standing waves, including other 7 peaks above 0.9 between 0.83THz and 1.55THz. Such a tunable multi-band absorber with multiple modulation methods may find extended applications in active integrated terahertz devices.
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36
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Erçağlar V, Hajian H, Serebryannikov AE, Ozbay E. Multifunctional tunable gradient metasurfaces for terahertz beam splitting and light absorption. OPTICS LETTERS 2021; 46:3953-3956. [PMID: 34388783 DOI: 10.1364/ol.435197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
Obtaining functional devices with tunable features is beneficial to advance terahertz (THz) science and technology. Here, we propose multifunctional gradient metasurfaces that are composed of a periodic array of binary Si microcylinders integrated with VO2 and graphene. The metasurfaces act as transmittive (reflective) beamsplitters for the dielectric (metallic) phase of VO2 with a switchable characteristic. Moreover, by integrating the metasurfaces with graphene and modifying its chemical potential, one can tune the intensity of the split beam as well as obtain nearly perfect resonant absorptions. Consequently, the proposed metasurfaces can find potential applications in THz interferometers, multiplexers, and light absorbers.
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37
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Liu W, Xu J, Song Z. Bifunctional terahertz modulator for beam steering and broadband absorption based on a hybrid structure of graphene and vanadium dioxide. OPTICS EXPRESS 2021; 29:23331-23340. [PMID: 34614600 DOI: 10.1364/oe.433364] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 07/02/2021] [Indexed: 06/13/2023]
Abstract
A bifunctional metamaterial is proposed based on a hybrid graphene and vanadium dioxide (VO2) configuration, which can realize a dynamic switch between beam steering and broadband absorption. The structure consists of a VO2 square, graphene patch, topas spacer, VO2 film, topas spacer, and metal substrate. When VO2 is in the metallic state, the structure serves as a coding metamaterial. By engineering different sizes of the top VO2 square and adjusting the Fermi energy level of graphene, the incident wave is scattered in different patterns. When VO2 is in the dielectric state, the structure serves as a broadband absorber. By changing the Fermi energy level of graphene from 0.0 eV to 0.9 eV, absorptance can be gradually changed and working bandwidth widens. There is an absorption band with near 100% absorptance from 0.9 THz to 1.35 THz when the Fermi energy level is 0.73 eV. And the designed broadband absorber is polarization-insensitive within the incident angle of 50°. Our work may show great potential in applications such as terahertz switching and modulation.
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38
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Zhang M, Song Z. Switchable terahertz metamaterial absorber with broadband absorption and multiband absorption. OPTICS EXPRESS 2021; 29:21551-21561. [PMID: 34265940 DOI: 10.1364/oe.432967] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 06/15/2021] [Indexed: 06/13/2023]
Abstract
Based on the phase-transition property of vanadium dioxide (VO2), a terahertz bifunctional absorber is proposed with switchable functionalities of broadband absorption and multiband absorption. When VO2 is metal, the system is regarded as a broadband absorber, which is composed of VO2 patch, topas spacer, and VO2 film with metallic disks inserted. The system obtains a broadband absorption with absorptance >90% from 3.25 THz to 7.08 THz. Moreover, the designed broadband absorber has a stable performance within the incident angle range of 50°. When VO2 is dielectric, multiband absorption with six peaks is realized in the designed system. Graphene and the metallic disk-shaped array play the dominant role in the mechanism of multiband absorption. Through changing the Fermi energy level of graphene, the performance of multiband absorption can be dynamically adjusted. Because of the switchable functionalities, the proposed design may have potential application in the fields of intelligent absorption and terahertz switch.
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39
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Zhang C, Zhang H, Ling F, Zhang B. Dual-regulated broadband terahertz absorber based on vanadium dioxide and graphene. APPLIED OPTICS 2021; 60:4835-4840. [PMID: 34143037 DOI: 10.1364/ao.426396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/12/2021] [Indexed: 06/12/2023]
Abstract
A tunable broadband terahertz (THz) absorber based on vanadium dioxide (${{\rm VO}_2}$) and graphene is proposed. The absorber, consisting of the ${{\rm VO}_2}$ square loop, polymethacrylimide (PMI) dielectric layer, and a layer of unpatterned graphene, can achieve absorption over 90% from 1.04 THz to 5.51 THz and relative bandwidth of up to 136.5% under normal incidence. Its absorption bandwidth and absorption peak can be adjusted by changing the conductivity of ${{\rm VO}_2}$ or the chemical potential of graphene. The physical mechanism of the absorber is analyzed in detail by the use of the impedance matching theory and the electric field distributions of the ${{\rm VO}_2}$ layer and graphene layer. The proposed absorber, with polarization insensitivity and incidence angle of 30° for both TE and TM polarizations, may have potential applications in tunable sensors, modulators, and imaging.
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40
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Liang J, Zhang K, Lei D, Yu L, Wang S. Bandwidth-tunable THz absorber based on diagonally distributed double-sized VO 2 disks. APPLIED OPTICS 2021; 60:3062-3070. [PMID: 33983201 DOI: 10.1364/ao.417054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 02/17/2021] [Indexed: 06/12/2023]
Abstract
Terahertz absorbers combined with phase-changing VO2 are a class of stealth materials with adjustable absorptance. However, such absorbers still suffer from insufficient absorption bandwidth. We propose a three-layer terahertz (THz) absorber, consisting of an array of diagonally distributed double-sized VO2 disks on a silica-coated gold film. We find this structure can generate the superposition of three resonant absorption peaks to broaden the absorption band. The finite element simulation (FES) results show that the absorption bandwidth can be adjusted from 2.63 to 5.04 THz by simply changing the sizes of the VO2 disks. In addition, the peak absorptance can be continuously regulated from 9.8% to 96% by varying the conductivity of VO2. Finally, the absorber is polarization-insensitive and has wide-angle absorption. The wide absorption band and adjustable bandwidth of the absorbers have important applications potentially for intelligent stealth materials.
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41
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Kang L, Wu Y, Werner DH. Active terahertz spin Hall effect in vanadium dioxide metasurfaces. OPTICS EXPRESS 2021; 29:8816-8823. [PMID: 33820323 DOI: 10.1364/oe.421283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 02/23/2021] [Indexed: 06/12/2023]
Abstract
Insulator-to-metal transition induces large material property variations in vanadium dioxide (VO2) over a broad frequency band. VO2, therefore, has been introduced into metallic resonating structures to realize reconfigurable metadevices from microwave to optical wavelengths. Beyond enabling metal/VO2 hybrid meta-atoms, in the THz regime metallic-phase VO2 micro-structures can support strong electromagnetic resonances, offering great potential in active manipulation of THz radiation. In this paper, we show that VO2 dipole antennas can be used to realize geometric phase coded metasurfaces for wave-front shaping and polarization rotation of THz waves. Moreover, we demonstrate that the corresponding efficiency of the THz spin Hall effect is closely related to VO2's THz electrical conductivity. In light of the dispersionless nature of the geometric phase, our study indicates that metasurfaces constructed by VO2 subwavelength resonators are good candidates for active control of broadband THz radiation.
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42
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Ren Y, Zhou T, Jiang C, Tang B. Thermally switching between perfect absorber and asymmetric transmission in vanadium dioxide-assisted metamaterials. OPTICS EXPRESS 2021; 29:7666-7679. [PMID: 33726263 DOI: 10.1364/oe.418273] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 02/20/2021] [Indexed: 06/12/2023]
Abstract
In this paper, we propose a switchable bi-functional metamaterial device based on a hybrid gold-vanadium dioxide (VO2) nanostructure. Utilizing the property of a metal-to-insulator transition in VO2, perfect absorption and asymmetric transmission (AT) can be thermally switched for circularly polarized light in the near-infrared region. When VO2 is in the metallic state, the designed metamaterial device behaves as a chiral-selective plasmonic perfect absorber, which can result in an optical circular dichroism (CD) response with a maximum value ∼ 0.7. When VO2 is in the insulating state, the proposed metamaterial device exhibits a dual-band AT effect. The combined hybridization model and electromagnetic field distributions are presented to explain the physical mechanisms of chiral-selective perfect absorption and AT effect, respectively. The influences of structure parameters on CD response and AT effect are also discussed. Moreover, the proposed switchable bi-functional device is robust against the incident angle for obtaining perfect absorption and strong CD response as well as the AT effect. Our work may provide a promising path for the development of multifunctional optoelectronic devices, such as thermal emitters, optical modulators, CD spectroscopy, optical isolator, etc.
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43
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Pouyan SM, Miri M, Sheikhi MH. Design and numerical analysis of a high-performance optical modulator based on Si-VO 2 Bragg grating waveguide. APPLIED OPTICS 2021; 60:1083-1091. [PMID: 33690555 DOI: 10.1364/ao.415019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 12/30/2020] [Indexed: 06/12/2023]
Abstract
Design and numerical characterization of a high-performance VO2-based optical modulator are proposed. The modulation is achieved by the phase transition of VO2 in a Bragg grating which can be formed by the selective VO2 deposition on a silicon strip waveguide. The interplay of the Bragg reflection and the inherent loss of the metal phase VO2 is used to increase the extinction ratio (ER) while the similarity of the refractive indices of the silicon and insulator phase VO2 resulted in a low insertion loss (IL). ER and IL of the modulator are 34.5 dB and 3.4 dB, respectively, at the wavelength of 1.55 µm, and they are, respectively, above 33 dB and below 3.5 dB across the entire optical C-band. The ER can be improved to 110 dB at the expense of an increased IL of 7.3 dB. The energy consumption and the modulation speed are estimated by considering different VO2 triggering schemes, and it is shown that the energy consumption of 91.7fJ/bit and the speed of 14 THz can be achieved with the proper VO2 stimulation. Furthermore, the robustness of the device performance to fabrication errors is studied by simulating the effect of the variation in different geometrical parameters.
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Wu G, Jiao X, Wang Y, Zhao Z, Wang Y, Liu J. Ultra-wideband tunable metamaterial perfect absorber based on vanadium dioxide. OPTICS EXPRESS 2021; 29:2703-2711. [PMID: 33726461 DOI: 10.1364/oe.416227] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/04/2021] [Indexed: 06/12/2023]
Abstract
A dynamically adjustable ultra-wideband metamaterial perfect absorber (MPA) is proposed which consists of three resonance rings based on vanadium dioxide (VO2) and a metal ground layer separated by a dielectric spacer. The simulation results show that the terahertz (THz) absorption bandwidth of more than 90% absorptance reaches 3.30 THz, which covers from 2.34 to 5.64 THz, under different incident polarization angles. The range is better than that of previous VO2-based reports. Moreover, when the conductivity of VO2 changes from 200 S/m to 2×105 S/m, the absorption peak intensity can be adjusted continuously from 4% to 100%. The key is to optimize the geometric structure through interference cancellation and impedance matching theory, to achieve better absorption bandwidth and efficiency. Besides, the terahertz absorber has a wide-angle absorption effect both in TE and TM waves. Thus, the designed absorber may have many potential applications in modulating, sensing and imaging technology.
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Lu C, Lu Q, Gao M, Lin Y. Dynamic Manipulation of THz Waves Enabled by Phase-Transition VO 2 Thin Film. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:E114. [PMID: 33419046 PMCID: PMC7825355 DOI: 10.3390/nano11010114] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 12/27/2020] [Accepted: 12/31/2020] [Indexed: 11/26/2022]
Abstract
The reversible and multi-stimuli responsive insulator-metal transition of VO2, which enables dynamic modulation over the terahertz (THz) regime, has attracted plenty of attention for its potential applications in versatile active THz devices. Moreover, the investigation into the growth mechanism of VO2 films has led to improved film processing, more capable modulation and enhanced device compatibility into diverse THz applications. THz devices with VO2 as the key components exhibit remarkable response to external stimuli, which is not only applicable in THz modulators but also in rewritable optical memories by virtue of the intrinsic hysteresis behaviour of VO2. Depending on the predesigned device structure, the insulator-metal transition (IMT) of VO2 component can be controlled through thermal, electrical or optical methods. Recent research has paid special attention to the ultrafast modulation phenomenon observed in the photoinduced IMT, enabled by an intense femtosecond laser (fs laser) which supports "quasi-simultaneous" IMT within 1 ps. This progress report reviews the current state of the field, focusing on the material nature that gives rise to the modulation-allowed IMT for THz applications. An overview is presented of numerous IMT stimuli approaches with special emphasis on the underlying physical mechanisms. Subsequently, active manipulation of THz waves through pure VO2 film and VO2 hybrid metamaterials is surveyed, highlighting that VO2 can provide active modulation for a wide variety of applications. Finally, the common characteristics and future development directions of VO2-based tuneable THz devices are discussed.
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Affiliation(s)
- Chang Lu
- School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, China; (C.L.); (Q.L.)
- State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Qingjian Lu
- School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, China; (C.L.); (Q.L.)
- State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Min Gao
- School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, China; (C.L.); (Q.L.)
- State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Yuan Lin
- School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, China; (C.L.); (Q.L.)
- State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China
- Medico-Engineering Cooperation on Applied Medicine Research Center, University of Electronic Science and Technology of China, Chengdu 610054, China
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Ye L, Chen X, Zhu C, Li W, Zhang Y. Switchable broadband terahertz spatial modulators based on patterned graphene and vanadium dioxide. OPTICS EXPRESS 2020; 28:33948-33958. [PMID: 33182873 DOI: 10.1364/oe.406090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/17/2020] [Indexed: 06/11/2023]
Abstract
We numerically demonstrate a switchable broadband terahertz spatial modulator composed of ginkgo-leaf-patterned graphene and transition material vanadium dioxide (VO2). The phase transition property of VO2 is used to switch the spatial modulator from absorption mode to transmission mode, and the graphene behaves as dynamically adjustable material for a large scale of absorption and transmittance modulation. When VO2 is in the metallic state and the Fermi energy of graphene is set as 0.8 eV, the proposed modulator behaves as a broadband absorber with the absorbance over 85% from 1.33 to 2.83 THz. By adjusting the graphene Fermi level from 0 to 0.8 eV, the peak absorbance can be continuously tuned from 24.3% to near 100% under the absorption mode, and the transmittance at 2.5 THz can be continuously tuned from 87% to 35.5% under the transmission mode. To further increase the bandwidth, a three-layer-patterned-graphene is introduced into a new modulator design, which achieves a wide bandwidth of 3.13 THz for the absorbance over 85%. By the combination of the tunability of graphene and VO2, the proposed modulators not only can flexibly switch between dual-functional modulation modes of absorption and transmission but also possess deep modulation depth. Benefitting from the excellent modulation performance, the proposed switchable dual-functional spatial modulators may offer significant potential applications in various terahertz smart optoelectronic devices.
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Tunable Dual Broadband Terahertz Metamaterial Absorber Based on Vanadium Dioxide. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10207259] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
With the rapid development of terahertz technology, tunable high-efficiency broadband functional devices have become a research trend. In this research, a dynamically tunable dual broadband terahertz absorber based on the metamaterial structure of vanadium dioxide (VO2) is proposed and analyzed. The metamaterial is composed of patterned VO2 on the top layer, gold on the bottom layer and silicon dioxide (SiO2) as the middle dielectric layer. Simulation results show that two bandwidths of 90% absorption reach as wide as 2.32 THz from 1.87 to 4.19 THz and 2.03 THz from 8.70 to 10.73 THz under normal incidence. By changing the conductivity of VO2, the absorptance dynamically tuned from 2% to 94%. Moreover, it is verified that absorptance is insensitive to the polarization angle. The physical origin of this absorber is revealed through interference theory and matching impedance theory. We further investigate the physical mechanism of dual broadband absorption through electric field analysis. This design has potential applications in imaging, modulation and stealth technology.
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Luo J, Shi X, Luo X, Hu F, Li G. Broadband switchable terahertz half-/quarter-wave plate based on metal-VO 2 metamaterials. OPTICS EXPRESS 2020; 28:30861-30870. [PMID: 33115078 DOI: 10.1364/oe.406006] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 09/23/2020] [Indexed: 06/11/2023]
Abstract
We propose a metal-vanadium dioxide (VO2) metamaterial with broadband and functionality-switchable polarization conversion in the terahertz regime. Simulation results show that the function of the proposed metamaterial can be switched from a half-wave plate (HWP) to a quarter-wave plate (QWP) over a broad bandwidth of 0.66-1.40 THz, corresponding to a relative bandwidth of 71.8%. The HWP obtained when VO2 is in the insulating state has reflection of 90% and linear polarization conversion ratio exceeding 98% over the bandwidth of 0.58-1.40 THz. By transiting the phase of VO2 into the conducting state, the obtained QWP can convert the incident linearly-polarized wave to circularly-polarized wave with an ellipticity of 0.99 over 0.66-1.60 THz. Additionally, results show that the proposed broadband switchable HWP/QWP has a large angular tolerance. We expect that this broadband and switchable multi-functional wave plate will find applications in polarization-dependent terahertz systems including sensing, imaging, and telecommunications.
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Dong X, Luo X, Zhou Y, Lu Y, Hu F, Xu X, Li G. Switchable broadband and wide-angular terahertz asymmetric transmission based on a hybrid metal-VO 2 metasurface. OPTICS EXPRESS 2020; 28:30675-30685. [PMID: 33115063 DOI: 10.1364/oe.405173] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 09/20/2020] [Indexed: 06/11/2023]
Abstract
We propose a switchable broadband and wide-angular terahertz asymmetric transmission based on a spiral metasurface composed of metal and VO2 hybrid structures. Results show that asymmetric transmission reaching up to 15% can be switched on or off for circularly polarized terahertz waves when the phase of VO2 transits from the insulting state to the conducting state or reversely. Strikingly, we find that relatively high asymmetric transmission above 10% can be maintained over a broad bandwidth of 2.6-4.0 THz and also over a large incident angular range of 0°-45°. We further discover that as the incident angle increases, the dominant chirality of the proposed metasurface with VO2 in the conducting state can shift from intrinsic to extrinsic chirality. We expect this work will advance the engineering of switchable chiral metasurfaces and promote terahertz applications.
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Xu N, Liang Y, Hao Y, Mao M, Guo J, Liu H, Meng H, Wang F, Wei Z. A Thermal Tuning Meta-Duplex-Lens (MDL): Design and Characterization. NANOMATERIALS 2020; 10:nano10061135. [PMID: 32521772 PMCID: PMC7353178 DOI: 10.3390/nano10061135] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/01/2020] [Accepted: 06/06/2020] [Indexed: 11/23/2022]
Abstract
Multifunctional metasurfaces play an important role in the development of integrated optical paths. However, some of the realizations of current multifunctional metasurface devices depend on polarization selectivity, and others change the polarization state of the outgoing light. Here, based on vanadium dioxide (VO2) phase change material, a strategy to design a meta-duplex-lens (MDL) is proposed and numerical simulation calculations demonstrate that at low temperature (about 300 K), VO2 behaves as a dielectric so that the MDL can act as a transmission lens (transmission efficiency of 87.6%). Conversely, when VO2 enters the metallic state (about 355 K), the MDL has the ability to reflect and polymerize electromagnetic waves and works as a reflection lens (reflection efficiency of 85.1%). The dielectric waveguide and gap-surface plasmon (GSP) theories are used in transmission and reflection directions, respectively. In order to satisfy the coverage of the phase gradient in the range of 2π in both cases, we set the antenna as a nanopillar with a high aspect ratio. It is notable that, via symmetrical antennas acting in concert with VO2 phase change material, the polarization states of both the incident light and the outgoing light are not changed. This reversible tuning will play a significant role in the fields of imaging, optical storage devices, communication, sensors, etc.
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Affiliation(s)
- Ning Xu
- Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China; (N.X.); (Y.H.); (M.M.); (J.G.); (H.L.); (H.M.); (F.W.)
| | - Yaoyao Liang
- Centre de Nanosciences et de Nanotechnologies, CNRS, Université Paris-Sud—Université Paris-Saclay 10 Boulevard Thomas Gobert, 91120 Palaiseau, France;
| | - Yuan Hao
- Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China; (N.X.); (Y.H.); (M.M.); (J.G.); (H.L.); (H.M.); (F.W.)
| | - Min Mao
- Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China; (N.X.); (Y.H.); (M.M.); (J.G.); (H.L.); (H.M.); (F.W.)
| | - Jianping Guo
- Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China; (N.X.); (Y.H.); (M.M.); (J.G.); (H.L.); (H.M.); (F.W.)
| | - Hongzhan Liu
- Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China; (N.X.); (Y.H.); (M.M.); (J.G.); (H.L.); (H.M.); (F.W.)
| | - Hongyun Meng
- Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China; (N.X.); (Y.H.); (M.M.); (J.G.); (H.L.); (H.M.); (F.W.)
| | - Faqiang Wang
- Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China; (N.X.); (Y.H.); (M.M.); (J.G.); (H.L.); (H.M.); (F.W.)
| | - Zhongchao Wei
- Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China; (N.X.); (Y.H.); (M.M.); (J.G.); (H.L.); (H.M.); (F.W.)
- Correspondence: ; Tel.: +86-1311-955-1688
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