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Your search keyword '"Fu, Quanhong"' showing total 168 results
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168 results on '"Fu, Quanhong"'

1. Experimental Demonstration of Controllable PT and anti-PT Coupling in a non-Hermitian Metamaterial

Author

Li, Chang, Yang, Ruisheng, Huang, Xinchao, Fu, Quanhong, Fan, Yuancheng, and Zhang, Fuli

Subjects
Physics - Optics, Physics - Applied Physics
Abstract

Non-Hermiticity has recently emerged as a rapidly developing field due to its exotic characteristics related to open systems, where the dissipation plays a critical role. In the presence of balanced energy gain and loss with environment, the system exhibits parity-time (PT) symmetry, meanwhile as the conjugate counterpart, anti-PT symmetry can be achieved with dissipative coupling within the system. Here, we demonstrate the coherence of complex dissipative coupling can control the transition between PT and anti-PT symmetry in an electromagnetic metamaterial. Notably, the achievement of the anti-PT symmetric phase is independent of variations in dissipation. Furthermore, we observe phase transitions as the system crosses exceptional points in both anti-PT and PT symmetric metamaterial configurations, achieved by manipulating the frequency and dissipation of resonators. This work provides a promising metamaterial design for broader exploration of non-Hermitian physics and practical application with controllable Hamiltonian., Comment: 7 pages, 4 figures

Published
2024
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8. Controlling the toroidal excitations in metamaterials for high-Q response

Author

Fan, Yuancheng, Zhang, Fuli, Fu, Quanhong, Wei, Zeyong, and Li, Hongqiang

Subjects
Physics - Optics, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

The excitation of toroidal multipoles in metamaterials was investigated for high-Q response at a subwavelength scale. In this study, we explored the optimization of toroidal excitations in a planar metamaterial comprised of asymmetric split ring resonators (ASRRs). It was found that the scattering power of toroidal dipole can be remarkably strengthened by adjusting the characteristic parameter of ASRRs: asymmetric factor. Interestingly, the improvement in toroidal excitation accompanies increment on the Q-factor of the toroidal metamaterial; it is shown that both the scattering power of toroidal dipole and the Q-factor were increased more than one order by changing the asymmetric factor of ASRRs. The optimization in excitation of toroidal multipole provide opportunity to further increase the Q-factor of metamaterial and boost light-matter interactions at the subwavelength scale for potential applications in low-power nonlinear processing, and sensitive photonic applications., Comment: 9 pages, 5 figures

Published
2016

9. A metamaterial modulator based on electrically controllable electromagnetically induced transparency

Author

Fan, Yuancheng, Qiao, Tong, Zhang, Fuli, Fu, Quanhong, Dong, Jiajia, and Kong, Botao

Subjects
Physics - Optics, Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Soft Condensed Matter
Abstract

Electromagnetically induced transparency (EIT) is a promising technology for the enhancement of light-matter interactions, and recent demonstrations of the quantum EIT realized in artificial micro-structured medium have remarkably reduced the extreme requirement for experimental observation of EIT spectrum. In this paper, we propose to electrically control the EIT spectrum in a metamaterial for an electromagnetic modulator. A diode acting as a tunable resistor is loaded in the gap of two paired wires to inductively tune the magnetic resonance, which induces remarkable modulation on the EIT spectrum through the metamaterial sample. The experimental measurements confirmed that the prediction of electromagnetic modulation in three narrow bands on the EIT spectrum, and a modulation contrast of up to 31 dB was achieved on the transmission through the metamaterial. Our results may facilitate the study on active/dynamical technology in translational metamaterials, which connect extraordinary manipulations on the flow of light in metamaterials, e.g., the exotic EIT, and practical applications in industry.

Published
2016

10. An electrically switchable wideband metamaterial absorber based on graphene at P band

Author

Wang Liansheng, Xia Dongyan, Fu Quanhong, Ding Xueyong, and Wang Yuan

Subjects
metamaterial absorber, graphene, switchable, wideband, low frequency, Physics, QC1-999
Abstract

Graphene has the capability of dynamically tuning its conductivity through gate voltage. Based on this fact, an electrically switchable wideband metamaterial absorber at low frequencies is presented and investigated in this paper. Our calculated results show that its absorption is over 90% from 400 to 1,000 MHz with the Fermi level of graphene being at 0 eV and the absorption band can be switched by adjusting the Fermi level of graphene without changing its physical structure. Moreover, the surface current distribution enables us to reveal the switchable wideband absorption characteristics of our designed metamaterial absorber. At last, we prove that its absorption property is polarization-insensitive due to the rotational symmetry of the structural unit. This work may provide a further step in the development of switchable sensors and absorbers at low frequencies.

Published
2021
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12. A thermally reconfigurable metamaterial with switchable wideband absorption and sensing at THz band based on VO2 thin film.

Author

Wang, Liansheng, Xia, Dongyan, Fu, Quanhong, Wang, Yuan, and Ding, Xueyong

Subjects
PHASE transitions, METAL-insulator transitions, THIN films, LOW temperatures, OXYGEN consumption
Abstract

The VO2 thin film has the advantage of thermally controlled insulator-metal phase transition. Based on this, we presented a thermally reconfigurable metamaterial with switchable wideband absorption and sensing at THz band in this paper. At low temperature ( σ VO 2 = 2 0 S/m), the metamaterial can realize nearly perfect absorption at the range of 6.88–9 THz. When the temperature rises to a certain extent ( σ VO 2 = 2 × 1 0 5 S/m), an absorption peak which can be used to sensing appears at 4.08 THz with the permittivity sensitivity of 0.5 THz/PU. The metamaterial has the advantages of simple structure and switchable wideband absorption/sensing functions with potential application value on terahertz stealth, detection, sensing, and so on. [ABSTRACT FROM AUTHOR]

Published
2024
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13. Tunable mid-infrared coherent perfect absorption in a graphene meta-surface

Author

Fan, Yuancheng, Liu, Zhe, Zhang, Fuli, Zhao, Qian, Wei, Zeyong, Fu, Quanhong, Li, Junjie, Gu, Changzhi, and Li, Hongqiang

Subjects
Physics - Optics, Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science
Abstract

We exploited graphene nanoribbons based meta-surface to realize coherent perfect absorption (CPA) in the mid-infrared regime. It was shown that quasi-CPA frequencies, at which CPA can be demonstrated with proper phase modulations, exist for the graphene meta-surface with strong resonant behaviors. The CPA can be tuned substantially by merging the geometric design of the meta-surface and the electrical tunability of graphene. Furthermore, we found that the graphene nanoribbon meta-surface based CPA is realizable with experimental graphene data. The findings of CPA with graphene meta-surface can be generalized for potential applications in optical detections and signal processing with two-dimensional optoelectronic materials., Comment: 12 pages, 6 figures

Published
2015
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16. Titanium dioxide metasurface manipulating high-efficiency and broadband photonic spin Hall effect in visible regime

Author

Zhu Wei, Yang Ruisheng, Geng Guangzhou, Fan Yuancheng, Guo Xuyue, Li Peng, Fu Quanhong, Zhang Fuli, Gu Changzhi, and Li Junjie

Subjects
high-efficiency metasurface, photonic spin hall effect, spin-dependent trajectory propagation, spin-orbit coupling, Physics, QC1-999
Abstract

The interactions of photonic spin angular momentum and orbital angular momentum, i.e., the spin-orbit coupling in focused beams, evanescent waves or artificial photonic structures, have attracted intensive investigations for the unusual fundamental phenomena in physics and potential applications in optical and quantum systems. It is of fundamental importance to enhance performance of spin-orbit coupling in optics. Here, we demonstrate a titanium dioxide (TiO2)–based all-dielectric metasurface exhibiting a high efficient control of photonic spin Hall effect (PSHE) in a transmissive configuration. This metasurface can achieve high-efficiency symmetric spin-dependent trajectory propagation due to the spin-dependent Pancharatnam-Berry phase. The as-formed metadevices with high-aspect-ratio TiO2 nanofins are able to realize (86%, measured at 514 nm) and broadband PSHEs in visible regime. Our results provide useful insights on high-efficiency metasurfaces with versatile functionalities in visible regime.

Published
2020
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26. Actively modulated propagation of electromagnetic wave in hybrid metasurfaces containing graphene

Author

Nan Jiameng, Yang Ruisheng, Xu Jing, Fu Quanhong, Zhang Fuli, and Fan Yuancheng

Subjects
graphene metasurface, extraordinary transmission, modulator, conductivity, Electrical engineering. Electronics. Nuclear engineering, TK1-9971, Physics, QC1-999
Abstract

Here we present the actively modulated transportation of electromagnetic wave through hybrid metasurfaces containing graphene. The hybrid metasurfaces are composed of patterned metallic layers of extraordinary transmission and backed with graphene-sandwich layers. With the designed metallic layer with perforated structure, we demonstrated effective modulation on the on-resonance transmission amplitude by increasing the bias voltage from 0 to 4 V to electrically tune the Fermi level as well as the sheet resistance of the graphene-sandwich structure. We also found that the modulation depth can be further improved by properly designing the perforated metallic structure. By change the geometry from cut-wire structure to the “butterfly”-like pattern we preliminarily achieved 19.2% improvement on the on-resonance transmission modulation. The measured transmittances of the active metasurfaces show good agreement with the numerical simulations with fitted graphene sheet resistances. The hybrid metasurfaces presented in this work may be deployed in a wide range of applications based on active electromagnetic or optical modulations.

Published
2020
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40. Back Cover Image

Author

Yang, Ruisheng, primary, Xu, Jing, additional, Shen, Nian‐Hai, additional, Zhang, Fuli, additional, Fu, Quanhong, additional, Li, Junjie, additional, Li, Hongqiang, additional, and Fan, Yuancheng, additional

Published
2021
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