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Peng S, Lu X, Tang L, Chang X, Yan J, Shi Q, Chen K, Li J, Du L, Huang W. Thermal and mechanical THz modulation of flexible all-dielectric metamaterial. OPTICS EXPRESS 2023; 31:2644-2653. [PMID: 36785273 DOI: 10.1364/oe.481264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 12/13/2022] [Indexed: 06/18/2023]
Abstract
The implementation of Terahertz (THz) modulation is critical for applications in high-speed wireless communications, security screening and so on. Therefore, it is particularly significant to obtain THz wave modulation devices with stable and flexible performance, easy manipulation of the modulation method, and multi-functionality. Here, we propose a flexible all-dielectric metamaterial by embedding zirconia (ZrO2) microspheres into a vanadium dioxide/polydimethylsiloxane (VO2/PDMS) composite, which can achieve thermal and mechanical tuning of THz wave transmission. When the temperature of the ZrO2/VO2/PDMS metamaterial increases, VO2 changes from the insulating phase to the metallic phase, and the 1st (at 0.304 THz) and 2nd (at 0.414 THz) order magnetic resonances exhibit the tunability of 20 GHz and 15 GHz, respectively. When stretched, the 1st and 2nd order magnetic resonances show the tunability of 12 GHz and 10 GHz, respectively. In the meantime, there are accompanying changes in transmittance at the resonances. The ZrO2/VO2/PDMS all-dielectric metamaterial presented in this work provides an alternative strategy for developing actively tunable, flexible, and versatile THz devices. In addition, it has the merits of simple preparation and low cost, promising large-area and rapid preparation of meta-arrays.
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2
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Peng J, Zhang W, Suo P, Lin X, Yan X, Ma G. Lattice-induced strong coupling in symmetric and asymmetric split-ring metamaterial arrays. APPLIED OPTICS 2022; 61:9788-9794. [PMID: 36606807 DOI: 10.1364/ao.472096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 10/10/2022] [Indexed: 06/17/2023]
Abstract
The intrinsic link between surface plasmon modes (eigenmodes) and lattice modes in subwavelength periodic structures is investigated based on the split-ring metamaterial structure. The paper shows that the strong coupling between the eigenmodes and the lattice modes can be achieved by appropriately adjusting the period of the metamaterial structure, and the emergence of new, to the best of our knowledge, modes at low frequencies is observed, resulting in a lower spectral loss of a single hybrid resonance and an increase in its Q factor up to 110. In addition, an asymmetric double-split-ring structure is proposed, and the Fano resonance is excited, giving rise to a spectral line with three resonance valleys. The coupled harmonic-oscillator model is used to interpret the underlying coupling mechanism in lattice-induced transparent systems, which agrees well with our simulation results. This strong-coupling scheme between the lattice and the mixed modes of the metamaterial unit provides a new avenue to modulate lattice-induced transparency, high-Q resonance, and strong-field confinement, which may find applications in the design of ultrasensitive sensors, slow-light devices, as well as multiple frequency absorbers and other fields.
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Estakhri NM, Norris TB. Tunable quantum two-photon interference with reconfigurable metasurfaces using phase-change materials. OPTICS EXPRESS 2021; 29:14245-14259. [PMID: 33985148 DOI: 10.1364/oe.419892] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 04/12/2021] [Indexed: 06/12/2023]
Abstract
The ability of phase-change materials to reversibly and rapidly switch between two stable phases has driven their use in a number of applications such as data storage and optical modulators. Incorporating such materials into metasurfaces enables new approaches to the control of optical fields. In this article we present the design of novel switchable metasurfaces that enable the control of the nonclassical two-photon quantum interference. These structures require no static power consumption, operate at room temperature, and have high switching speed. For the first adaptive metasurface presented in this article, tunable nonclassical two-photon interference from -97.7% (anti-coalescence) to 75.48% (coalescence) is predicted. For the second adaptive geometry, the quantum interference switches from -59.42% (anti-coalescence) to 86.09% (coalescence) upon a thermally driven crystallographic phase transition. The development of compact and rapidly controllable quantum devices is opening up promising paths to brand-new quantum applications as well as the possibility of improving free space quantum logic gates, linear-optics bell experiments, and quantum phase estimation systems.
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Xing Q, Song C, Wang C, Xie Y, Huang S, Wang F, Lei Y, Yuan X, Zhang C, Mu L, Huang Y, Xiu F, Yan H. Tunable Terahertz Plasmons in Graphite Thin Films. PHYSICAL REVIEW LETTERS 2021; 126:147401. [PMID: 33891459 DOI: 10.1103/physrevlett.126.147401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 03/03/2021] [Indexed: 06/12/2023]
Abstract
Tunable terahertz plasmons are essential for reconfigurable photonics, which have been demonstrated in graphene through gating, though with relatively weak responses. Here we demonstrate strong terahertz plasmons in graphite thin films via infrared spectroscopy, with dramatic tunability by even a moderate temperature change or an in situ bias voltage. Meanwhile, through magnetoplasmon studies, we reveal that massive electrons and massless Dirac holes make comparable contributions to the plasmon response. Our study not only sets up a platform for further exploration of two-component plasmas, but also opens an avenue for terahertz modulation through electrical bias or all-optical means.
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Affiliation(s)
- Qiaoxia Xing
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Key Laboratory of Micro and Nano-Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
| | - Chaoyu Song
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Key Laboratory of Micro and Nano-Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
| | - Chong Wang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Key Laboratory of Micro and Nano-Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
| | - Yuangang Xie
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Key Laboratory of Micro and Nano-Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
| | - Shenyang Huang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Key Laboratory of Micro and Nano-Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
| | - Fanjie Wang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Key Laboratory of Micro and Nano-Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
| | - Yuchen Lei
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Key Laboratory of Micro and Nano-Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
| | - Xiang Yuan
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China
| | - Cheng Zhang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Lei Mu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Key Laboratory of Micro and Nano-Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
| | - Yuan Huang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Faxian Xiu
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
- Shanghai Research Center for Quantum Sciences, Shanghai 201315, China
| | - Hugen Yan
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
- Key Laboratory of Micro and Nano-Photonic Structures (Ministry of Education), Fudan University, Shanghai 200433, China
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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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Zhao Y, Wang L, Zhang Y, Qiao S, Liang S, Zhou T, Zhang X, Guo X, Feng Z, Lan F, Chen Z, Yang X, Yang Z. High-Speed Efficient Terahertz Modulation Based on Tunable Collective-Individual State Conversion within an Active 3 nm Two-Dimensional Electron Gas Metasurface. NANO LETTERS 2019; 19:7588-7597. [PMID: 31398289 DOI: 10.1021/acs.nanolett.9b01273] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Terahertz (THz) modulators are always realized by dynamically manipulating the conversion between different resonant modes within a single unit cell of an active metasurface. In this Letter, to achieve real high-speed THz modulation, we present a staggered netlike two-dimensional electron gas (2DEG) nanostructure composite metasurface that has two states: a collective state with massive surface resonant characteristics and an individual state with meta-atom resonant characteristics. By controlling the electron transport of the nanoscale 2DEG with an electrical grid, collective-individual state conversion can be realized in this composite metasurface. Unlike traditional resonant mode conversion confined in meta-units, this state conversion enables the resonant modes to be flexibly distributed throughout the metasurface, leading to a frequency shift of nearly 99% in both the simulated and experimental transmission spectra. Moreover, such a mechanism can effectively suppress parasitic modes and significantly reduce the capacitance of the metasurface. Thereby, this composite metasurface can efficiently control the transmission characteristics of THz waves with high-speed modulations. As a result, 93% modulation depth is observed in the static experiment and modulated sinusoidal signals up to 3 GHz are achieved in the dynamic experiment, while the -3 dB bandwidth can reach up to 1 GHz. This tunable collective-individual state conversion may have great application potential in wireless communication and coded imaging.
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Affiliation(s)
- Yuncheng Zhao
- School of Electronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , China
| | - Lan Wang
- School of Electronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , China
| | - Yaxin Zhang
- School of Electronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , China
| | - Shen Qiao
- School of Electronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , China
| | - Shixiong Liang
- National Key Laboratory of Application Specific Integrated Circuit , Hebei Semiconductor Research Institute , Shijiazhuang 050051 , China
| | - Tianchi Zhou
- School of Electronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , China
| | - Xilin Zhang
- School of Electronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , China
| | - Xiaoqing Guo
- School of Electronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , China
| | - Zhihong Feng
- National Key Laboratory of Application Specific Integrated Circuit , Hebei Semiconductor Research Institute , Shijiazhuang 050051 , China
| | - Feng Lan
- School of Electronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , China
| | - Zhi Chen
- School of Electronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , China
| | - Xiaobo Yang
- School of Electronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , China
| | - Ziqiang Yang
- School of Electronic Science and Engineering , University of Electronic Science and Technology of China , Chengdu 610054 , China
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Wang L, Zhang Y, Guo X, Chen T, Liang H, Hao X, Hou X, Kou W, Zhao Y, Zhou T, Liang S, Yang Z. A Review of THz Modulators with Dynamic Tunable Metasurfaces. NANOMATERIALS 2019; 9:nano9070965. [PMID: 31266235 PMCID: PMC6669754 DOI: 10.3390/nano9070965] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 06/13/2019] [Accepted: 06/28/2019] [Indexed: 11/16/2022]
Abstract
Terahertz (THz) radiation has received much attention during the past few decades for its potential applications in various fields, such as spectroscopy, imaging, and wireless communications. To use terahertz waves for data transmission in different application systems, the efficient and rapid modulation of terahertz waves is required and has become an in-depth research topic. Since the turn of the century, research on metasurfaces has rapidly developed, and the scope of novel functions and operating frequency ranges has been substantially expanded, especially in the terahertz range. The combination of metasurfaces and semiconductors has facilitated both new opportunities for the development of dynamic THz functional devices and significant achievements in THz modulators. This paper provides an overview of THz modulators based on different kinds of dynamic tunable metasurfaces combined with semiconductors, two-dimensional electron gas heterostructures, superconductors, phase-transition materials, graphene, and other 2D material. Based on the overview, a brief discussion with perspectives will be presented. We hope that this review will help more researchers learn about the recent developments and challenges of THz modulators and contribute to this field.
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Affiliation(s)
- Lan Wang
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Yaxin Zhang
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China.
| | - Xiaoqing Guo
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Ting Chen
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Huajie Liang
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Xiaolin Hao
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Xu Hou
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Wei Kou
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Yuncheng Zhao
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Tianchi Zhou
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China
| | - Shixiong Liang
- National Key Laboratory of Application Specific Integrated Circuit, Hebei Semiconductor Research Institute, Shijiazhuang 050051, China
| | - Ziqiang Yang
- Terahertz Science Cooperative Innovation Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chendu 610054, China.
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Srivastava YK, Manjappa M, Cong L, Krishnamoorthy HNS, Savinov V, Pitchappa P, Singh R. A Superconducting Dual-Channel Photonic Switch. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1801257. [PMID: 29870580 DOI: 10.1002/adma.201801257] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 04/17/2018] [Indexed: 05/20/2023]
Abstract
The mechanism of Cooper pair formation and its underlying physics has long occupied the investigation into high temperature (high-Tc ) cuprate superconductors. One of the ways to unravel this is to observe the ultrafast response present in the charge carrier dynamics of a photoexcited specimen. This results in an interesting approach to exploit the dissipation-less dynamic features of superconductors to be utilized for designing high-performance active subwavelength photonic devices with extremely low-loss operation. Here, dual-channel, ultrafast, all-optical switching and modulation between the resistive and the superconducting quantum mechanical phase is experimentally demonstrated. The ultrafast phase switching is demonstrated via modulation of sharp Fano resonance of a high-Tc yttrium barium copper oxide (YBCO) superconducting metamaterial device. Upon photoexcitation by femtosecond light pulses, the ultrasensitive cuprate superconductor undergoes dual dissociation-relaxation dynamics, with restoration of superconductivity within a cycle, and thereby establishes the existence of dual switching windows within a timescale of 80 ps. Pathways are explored to engineer the secondary dissociation channel which provides unprecedented control over the switching speed. Most importantly, the results envision new ways to accomplish low-loss, ultrafast, and ultrasensitive dual-channel switching applications that are inaccessible through conventional metallic and dielectric based metamaterials.
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Affiliation(s)
- Yogesh Kumar Srivastava
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
- Center for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Manukumara Manjappa
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
- Center for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Longqing Cong
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
- Center for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Harish N S Krishnamoorthy
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
- Center for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Vassili Savinov
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, UK
| | - Prakash Pitchappa
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
- Center for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Ranjan Singh
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
- Center for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
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9
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Fomin VM, Rezaev RO, Levchenko EA, Grimm D, Schmidt OG. Superconducting properties of nanostructured microhelices. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:395301. [PMID: 28677599 DOI: 10.1088/1361-648x/aa7dbe] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Superconducting micro- and nanohelices are proposed for the first time. A theoretical investigation of the superconducting state in the helical coils at the micro- and nanoscale is performed within the time-dependent Ginzburg-Landau approach. The pattern and number of vortices in a stationary distribution are determined by their confinement to the ultrathin helical coil and can therefore be efficiently controlled by the spiral stripe width and the spiral pitch distance for both dense and sparse coils. Quasi-degeneracy of vortex patterns is manifested in the helical coil when the number of vortices is incommensurable with the total number of half-turns. With increasing radius, superconducting helical coils provide a physical realization of a transition from the vortex pattern peculiar to an open tube to that of a planar stripe.
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Affiliation(s)
- Vladimir M Fomin
- Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstraße 20, D-01069 Dresden, Germany
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10
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Zhou G, Dai P, Wu J, Jin B, Wen Q, Zhu G, Shen Z, Zhang C, Kang L, Xu W, Chen J, Wu P. Broadband and high modulation-depth THz modulator using low bias controlled VO 2-integrated metasurface. OPTICS EXPRESS 2017; 25:17322-17328. [PMID: 28789224 DOI: 10.1364/oe.25.017322] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 07/06/2017] [Indexed: 06/07/2023]
Abstract
An active vanadium dioxide integrated metasurface offering broadband transmitted terahertz wave modulation with large modulation-depth under electrical control is demonstrated. The device consists of metal bias-lines arranged with grid-structure patterned vanadium dioxide (VO2) film on sapphire substrate. Amplitude transmission is continuously tuned from more than 78% to 28% or lower in the frequency range from 0.3 THz to 1.0 THz, by means of electrical bias at temperature of 68 °C. The physical mechanism underlying the device's electrical tunability is investigated and found to be attributed to the ohmic heating. The developed device possessing over 87% modulation depth with 0.7 THz frequency band is expected to have many potential applications in THz regime such as tunable THz attenuator.
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11
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Li L, Yin H. Bound States in the Continuum in double layer structures. Sci Rep 2016; 6:26988. [PMID: 27245435 PMCID: PMC4887898 DOI: 10.1038/srep26988] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 05/10/2016] [Indexed: 01/21/2023] Open
Abstract
We have theoretically investigated the reflectivity spectrums of single- and double-layer photonic crystal slabs and the dielectric multilayer stack. It is shown that light can be perfectly confined in a single-layer photonic crystal slab at a given incident angle by changing the thickness, permittivity or hole radius of the structure. With a tunable double-layer photonic crystal slab, we demonstrate that the occurrence of tunable bound states in the continuum is dependent on the spacing between two slabs. Moreover, by analytically investigating the Drude lossless multilayer stack model, the spacing dependence of bound states in the continuum is characterized as the phase matching condition that illuminates these states can occur at any nonzero incident angles by adjusting the spacing.
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Affiliation(s)
- LiangSheng Li
- Science and Technology on Electromagnetic Scattering Laboratory, Beijing 100854, China
| | - Hongcheng Yin
- Science and Technology on Electromagnetic Scattering Laboratory, Beijing 100854, China
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12
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Zheludev NI, Plum E. Reconfigurable nanomechanical photonic metamaterials. NATURE NANOTECHNOLOGY 2016; 11:16-22. [PMID: 26740040 DOI: 10.1038/nnano.2015.302] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 11/18/2015] [Indexed: 05/26/2023]
Abstract
The changing balance of forces at the nanoscale offers the opportunity to develop a new generation of spatially reconfigurable nanomembrane metamaterials in which electromagnetic Coulomb, Lorentz and Ampère forces, as well as thermal stimulation and optical signals, can be engaged to dynamically change their optical properties. Individual building blocks of such metamaterials, the metamolecules, and their arrays fabricated on elastic dielectric membranes can be reconfigured to achieve optical modulation at high frequencies, potentially reaching the gigahertz range. Mechanical and optical resonances enhance the magnitude of actuation and optical response within these nanostructures, which can be driven by electric signals of only a few volts or optical signals with power of only a few milliwatts. We envisage switchable, electro-optical, magneto-optical and nonlinear metamaterials that are compact and silicon-nanofabrication-technology compatible with functionalities surpassing those of natural media by orders of magnitude in some key design parameters.
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Affiliation(s)
- Nikolay I Zheludev
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton SO17 1BJ, UK
- The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, 637371 Singapore, Singapore
| | - Eric Plum
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton SO17 1BJ, UK
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13
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Highly tunable hybrid metamaterials employing split-ring resonators strongly coupled to graphene surface plasmons. Nat Commun 2015; 6:8969. [PMID: 26584781 PMCID: PMC4673875 DOI: 10.1038/ncomms9969] [Citation(s) in RCA: 172] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 10/21/2015] [Indexed: 01/22/2023] Open
Abstract
Metamaterials and plasmonics are powerful tools for unconventional manipulation and harnessing of light. Metamaterials can be engineered to possess intriguing properties lacking in natural materials, such as negative refractive index. Plasmonics offers capabilities of confining light in subwavelength dimensions and enhancing light–matter interactions. Recently, the technological potential of graphene-based plasmonics has been recognized as the latter features large tunability, higher field-confinement and lower loss compared with metal-based plasmonics. Here, we introduce hybrid structures comprising graphene plasmonic resonators coupled to conventional split-ring resonators, thus demonstrating a type of highly tunable metamaterial, where the interaction between the two resonances reaches the strong-coupling regime. Such hybrid metamaterials are employed as high-speed THz modulators, exhibiting ∼60% transmission modulation and operating speed in excess of 40 MHz. This device concept also provides a platform for exploring cavity-enhanced light–matter interactions and optical processes in graphene plasmonic structures for applications including sensing, photo-detection and nonlinear frequency generation. Realizing tunable metamaterials across a broad spectral range is of great interest. Here, Liu et al. introduce hybrid structures comprising graphene plasmonic resonators strongly coupled to conventional split-ring resonators and reach 60% transmission modulation with an operating speed above 40 MHz.
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Zhu W, Song Q, Yan L, Zhang W, Wu PC, Chin LK, Cai H, Tsai DP, Shen ZX, Deng TW, Ting SK, Gu Y, Lo GQ, Kwong DL, Yang ZC, Huang R, Liu AQ, Zheludev N. A flat lens with tunable phase gradient by using random access reconfigurable metamaterial. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:4739-43. [PMID: 26184076 DOI: 10.1002/adma.201501943] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 06/03/2015] [Indexed: 05/27/2023]
Abstract
The first demonstration of an optofluidic metamaterial is reported where resonant properties of every individual metamolecule can be continuously tuned at will using a microfluidic system. This is called a random-access reconfigurable metamaterial, which is used to provide the first demonstration of a tunable flat lens with wavefront-reshaping capabilities.
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Affiliation(s)
- Weiming Zhu
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798
| | - Qinghua Song
- Université Paris-Est, UPEM, Marne-la-Vallée, Paris, F-77454, France
| | - Libin Yan
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798
| | - Wu Zhang
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798
| | - Pin-Chieh Wu
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798
| | - Lip Ket Chin
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798
| | - Hong Cai
- Institute of Microelectronics, A*STAR, Singapore, 117686
| | - Din Ping Tsai
- Department of Physics, National Taiwan University, Taipei, 10617, Taiwan
| | - Zhong Xiang Shen
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798
| | - Tian Wei Deng
- Temasek Laboratories, 5A Engineering Drive 1, Singapore, 117411
| | - Sing Kwong Ting
- Temasek Laboratories, 5A Engineering Drive 1, Singapore, 117411
| | - Yuandong Gu
- Institute of Microelectronics, A*STAR, Singapore, 117686
| | - Guo Qiang Lo
- Institute of Microelectronics, A*STAR, Singapore, 117686
| | - Dim Lee Kwong
- Institute of Microelectronics, A*STAR, Singapore, 117686
| | - Zhen Chuan Yang
- Institute of Microelectronics, Peking University, Beijing, 100871, China
| | - Ru Huang
- Institute of Microelectronics, Peking University, Beijing, 100871, China
| | - Ai-Qun Liu
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798
| | - Nikolay Zheludev
- Optoelectronics Research Centre, Southampton, SO17 1BJ, UK
- Centre for Disruptive Photonic Technologies, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371
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Zhang Y, Qiao S, Liang S, Wu Z, Yang Z, Feng Z, Sun H, Zhou Y, Sun L, Chen Z, Zou X, Zhang B, Hu J, Li S, Chen Q, Li L, Xu G, Zhao Y, Liu S. Gbps terahertz external modulator based on a composite metamaterial with a double-channel heterostructure. NANO LETTERS 2015; 15:3501-6. [PMID: 25919444 DOI: 10.1021/acs.nanolett.5b00869] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The past few decades have witnessed a substantial increase in terahertz (THz) research. Utilizing THz waves to transmit communication and imaging data has created a high demand for phase and amplitude modulation. However, current active THz devices, including modulators and switches, still cannot meet THz system demands. Double-channel heterostructures, an alternative semiconductor system, can support nanoscale two-dimensional electron gases (2DEGs) with high carrier concentration and mobility and provide a new way to develop active THz devices. In this Letter, we present a composite metamaterial structure that combines an equivalent collective dipolar array with a double-channel heterostructure to obtain an effective, ultrafast, and all-electronic grid-controlled THz modulator. Electrical control allows for resonant mode conversion between two different dipolar resonances in the active device, which significantly improves the modulation speed and depth. This THz modulator is the first to achieve a 1 GHz modulation speed and 85% modulation depth during real-time dynamic tests. Moreover, a 1.19 rad phase shift was realized. A wireless free-space-modulation THz communication system based on this external THz modulator was tested using 0.2 Gbps eye patterns. Therefore, this active composite metamaterial modulator provides a basis for the development of effective and ultrafast dynamic devices for THz wireless communication and imaging systems.
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Affiliation(s)
- Yaxin Zhang
- †Terahertz Science Cooperative Innovation Center, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Shen Qiao
- †Terahertz Science Cooperative Innovation Center, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Shixiong Liang
- ‡National Key Laboratory of Application Specific Integrated Circuit, Hebei Semiconductor Research Institute, Shijiazhuang 050000, China
| | - Zhenhua Wu
- †Terahertz Science Cooperative Innovation Center, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Ziqiang Yang
- †Terahertz Science Cooperative Innovation Center, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Zhihong Feng
- ‡National Key Laboratory of Application Specific Integrated Circuit, Hebei Semiconductor Research Institute, Shijiazhuang 050000, China
| | - Han Sun
- †Terahertz Science Cooperative Innovation Center, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Yucong Zhou
- †Terahertz Science Cooperative Innovation Center, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Linlin Sun
- †Terahertz Science Cooperative Innovation Center, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Zhi Chen
- §National Key Laboratory of Communication, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Xianbing Zou
- §National Key Laboratory of Communication, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Bo Zhang
- ∥School of Electronics Engineering, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Jianhao Hu
- §National Key Laboratory of Communication, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Shaoqian Li
- §National Key Laboratory of Communication, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Qin Chen
- ⊥Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123, P. R. China
| | - Ling Li
- †Terahertz Science Cooperative Innovation Center, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Gaiqi Xu
- †Terahertz Science Cooperative Innovation Center, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Yuncheng Zhao
- †Terahertz Science Cooperative Innovation Center, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Shenggang Liu
- †Terahertz Science Cooperative Innovation Center, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
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16
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Ou JY, Plum E, Zhang J, Zheludev NI. An electromechanically reconfigurable plasmonic metamaterial operating in the near-infrared. NATURE NANOTECHNOLOGY 2013; 8:252-255. [PMID: 23503091 DOI: 10.1038/nnano.2013.25] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 01/31/2013] [Indexed: 05/27/2023]
Abstract
Current efforts in metamaterials research focus on attaining dynamic functionalities such as tunability, switching and modulation of electromagnetic waves. To this end, various approaches have emerged, including embedded varactors, phase-change media, the use of liquid crystals, electrical modulation with graphene and superconductors, and carrier injection or depletion in semiconductor substrates. However, tuning, switching and modulating metamaterial properties in the visible and near-infrared range remain major technological challenges: indeed, the existing microelectromechanical solutions used for the sub-terahertz and terahertz regimes cannot be shrunk by two to three orders of magnitude to enter the optical spectral range. Here, we develop a new type of metamaterial operating in the optical part of the spectrum that is three orders of magnitude faster than previously reported electrically reconfigurable metamaterials. The metamaterial is actuated by electrostatic forces arising from the application of only a few volts to its nanoscale building blocks-the plasmonic metamolecules-that are supported by pairs of parallel strings cut from a flexible silicon nitride membrane of nanoscale thickness. These strings, of picogram mass, can be driven synchronously to megahertz frequencies to electromechanically reconfigure the metamolecules and dramatically change the transmission and reflection spectra of the metamaterial. The metamaterial's colossal electro-optical response (on the order of 10(-5)-10(-6) m V(-1)) allows for either fast continuous tuning of its optical properties (up to 8% optical signal modulation at up to megahertz rates) or high-contrast irreversible switching in a device only 100 nm thick, without the need for external polarizers and analysers.
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Affiliation(s)
- Jun-Yu Ou
- Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton SO17 1BJ, UK
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