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Yao J, Hsu WL, Liang Y, Lin R, Chen MK, Tsai DP. Nonlocal metasurface for dark-field edge emission. SCIENCE ADVANCES 2024; 10:eadn2752. [PMID: 38630828 PMCID: PMC11023491 DOI: 10.1126/sciadv.adn2752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 03/13/2024] [Indexed: 04/19/2024]
Abstract
Nonlocal effects originating from interactions between neighboring meta-atoms introduce additional degrees of freedom for peculiar characteristics of metadevices, such as enhancement, selectivity, and spatial modulation. However, they are generally difficult to manipulate because of the collective responses of multiple meta-atoms. Here, we experimentally demonstrate the nonlocal metasurface to realize the spatial modulation of dark-field emission. Plasmonic asymmetric split rings (ASRs) are designed to simultaneously excite local dipole resonance and nonlocal quasi-bound states in the continuum and spatially extended modes. With one type of unit, nonlocal effects are tailored by varying array periods. ASRs at the metasurface's edge lack sufficient interactions, resulting in stronger dark-field scattering and thus edge emission properties of the metasurface. Pixel-level spatial control is demonstrated by simply erasing some units, providing more flexibility than conventional local metasurfaces. This work paves the way for manipulating nonlocal effects and facilitates applications in optical trapping and sorting at the nanoscale.
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Affiliation(s)
- Jin Yao
- Department of Electrical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Wei-Lun Hsu
- Department of Optics and Photonics, National Central University, Taoyuan 320371, Taiwan
| | - Yao Liang
- Department of Electrical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Rong Lin
- Department of Electrical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Mu Ku Chen
- Department of Electrical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, China
- Centre for Biosystems, Neuroscience, and Nanotechnology, City University of Hong Kong, Kowloon, Hong Kong SAR, China
- State Key Laboratory of Terahertz and Millimeter Waves, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Din Ping Tsai
- Department of Electrical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, China
- Centre for Biosystems, Neuroscience, and Nanotechnology, City University of Hong Kong, Kowloon, Hong Kong SAR, China
- State Key Laboratory of Terahertz and Millimeter Waves, City University of Hong Kong, Kowloon, Hong Kong SAR, China
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Yu Z, Li H, Zhao W, Huang PS, Lin YT, Yao J, Li W, Zhao Q, Wu PC, Li B, Genevet P, Song Q, Lai P. High-security learning-based optical encryption assisted by disordered metasurface. Nat Commun 2024; 15:2607. [PMID: 38521827 PMCID: PMC10960874 DOI: 10.1038/s41467-024-46946-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 03/15/2024] [Indexed: 03/25/2024] Open
Abstract
Artificial intelligence has gained significant attention for exploiting optical scattering for optical encryption. Conventional scattering media are inevitably influenced by instability or perturbations, and hence unsuitable for long-term scenarios. Additionally, the plaintext can be easily compromised due to the single channel within the medium and one-to-one mapping between input and output. To mitigate these issues, a stable spin-multiplexing disordered metasurface (DM) with numerous polarized transmission channels serves as the scattering medium, and a double-secure procedure with superposition of plaintext and security key achieves two-to-one mapping between input and output. In attack analysis, when the ciphertext, security key, and incident polarization are all correct, the plaintext can be decrypted. This system demonstrates excellent decryption efficiency over extended periods in noisy environments. The DM, functioning as an ultra-stable and active speckle generator, coupled with the double-secure approach, creates a highly secure speckle-based cryptosystem with immense potentials for practical applications.
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Affiliation(s)
- Zhipeng Yu
- Department of Biomedical Engineering, Hong Kong Polytechnic University, Hong Kong SAR, China
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, China
- Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, Guangdong, China
| | - Huanhao Li
- Department of Biomedical Engineering, Hong Kong Polytechnic University, Hong Kong SAR, China
- Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, Guangdong, China
| | - Wannian Zhao
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, China
| | - Po-Sheng Huang
- Department of Photonics, National Cheng Kung University, Tainan, Taiwan
| | - Yu-Tsung Lin
- Department of Photonics, National Cheng Kung University, Tainan, Taiwan
| | - Jing Yao
- Department of Biomedical Engineering, Hong Kong Polytechnic University, Hong Kong SAR, China
- Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, Guangdong, China
| | - Wenzhao Li
- Department of Biomedical Engineering, Hong Kong Polytechnic University, Hong Kong SAR, China
- Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, Guangdong, China
| | - Qi Zhao
- Department of Biomedical Engineering, Hong Kong Polytechnic University, Hong Kong SAR, China
- Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, Guangdong, China
| | - Pin Chieh Wu
- Department of Photonics, National Cheng Kung University, Tainan, Taiwan
- Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan, Taiwan
- Meta-nanoPhotonics Center, National Cheng Kung University, Tainan, Taiwan
| | - Bo Li
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, China
- Suzhou Laboratory, Suzhou, China
| | - Patrice Genevet
- Physics Department, Colorado School of Mines, Golden, CO, USA.
| | - Qinghua Song
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, Guangdong, China.
- Suzhou Laboratory, Suzhou, China.
| | - Puxiang Lai
- Department of Biomedical Engineering, Hong Kong Polytechnic University, Hong Kong SAR, China.
- Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, Guangdong, China.
- Photonics Research Institute, Hong Kong Polytechnic University, Hong Kong SAR, China.
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Madeleine T, Podoliak N, Buchnev O, Membrillo Solis I, Orlova T, van Rossem M, Kaczmarek M, D’Alessandro G, Brodzki J. Topological Learning for the Classification of Disorder: An Application to the Design of Metasurfaces. ACS NANO 2023; 18. [PMID: 38108267 PMCID: PMC10796169 DOI: 10.1021/acsnano.3c08776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 12/01/2023] [Accepted: 12/06/2023] [Indexed: 12/19/2023]
Abstract
Structural disorder can improve the optical properties of metasurfaces, whether it is emerging from some large-scale fabrication methods or explicitly designed and built lithographically. For example, correlated disorder, induced by a minimum inter-nanostructure distance or by hyperuniformity properties, is particularly beneficial for light extraction. Inspired by topology, we introduce numerical descriptors to provide quantitative measures of disorder with universal properties, suitable to treat both uncorrelated and correlated disorder at all length scales. The accuracy of these topological descriptors is illustrated both theoretically and experimentally by using them to design plasmonic metasurfaces with controlled disorder that we then correlate to the strength of their surface lattice resonances. These descriptors are an example of topological tools that can be used for the fast and accurate design of disordered structures or as aid in improving their fabrication methods.
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Affiliation(s)
- Tristan Madeleine
- Mathematical
Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Nina Podoliak
- Physics
and Astronomy, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Oleksandr Buchnev
- Optoelectronics
Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | | | - Tetiana Orlova
- Physics
and Astronomy, University of Southampton, Southampton SO17 1BJ, United Kingdom
- Infochemistry
Scientific Center, ITMO University, 9 Lomonosova Street, Saint-Petersburg, 191002, Russia
| | - Maria van Rossem
- Physics
and Astronomy, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Malgosia Kaczmarek
- Physics
and Astronomy, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | | | - Jacek Brodzki
- Mathematical
Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
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Wu G, Zhou Y, Hong M. Sub-50 nm optical imaging in ambient air with 10× objective lens enabled by hyper-hemi-microsphere. LIGHT, SCIENCE & APPLICATIONS 2023; 12:49. [PMID: 36854662 PMCID: PMC9974943 DOI: 10.1038/s41377-023-01091-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 01/05/2023] [Accepted: 02/01/2023] [Indexed: 06/18/2023]
Abstract
Optical microsphere nanoscope has great potential in the inspection of integrated circuit chips for semiconductor industry and morphological characterization in biology due to its superior resolving power and label-free characteristics. However, its resolution in ambient air is restricted by the magnification and numerical aperture (NA) of microsphere. High magnification objective lens is required to be coupled with microsphere for nano-imaging beyond the diffraction limit. To overcome these challenges, in this work, high refractive index hyper-hemi-microspheres with tunable magnification up to 10× are proposed and realized by accurately tailoring their thickness with focused ion beam (FIB) milling. The effective refractive index is put forward to guide the design of hyper-hemi-microspheres. Experiments demonstrate that the imaging resolution and contrast of a hyper-hemi-microsphere with a higher magnification and larger NA excel those of a microsphere in air. Besides, the hyper-hemi-microsphere could resolve ~50 nm feature with higher image fidelity and contrast compared with liquid immersed high refractive index microspheres. With a hyper-hemi-microsphere composed microscale compound lens configuration, sub-50 nm optical imaging in ambient air is realized by only coupling with a 10× objective lens (NA = 0.3), which enhances a conventional microscope imaging power about an order of magnitude.
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Affiliation(s)
- Guangxing Wu
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117576, Singapore
| | - Yan Zhou
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117576, Singapore
- Peng Cheng Laboratory, Shenzhen, 518055, China
| | - Minghui Hong
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117576, Singapore.
- School of Aerospace Engineering, Xiamen University, Xiamen, 361005, China.
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Li C, Cheng H, Luo X, Cheng Z, Zhai X. A High Quality-Factor Optical Modulator with Hybrid Graphene-Dielectric Metasurface Based on the Quasi-Bound States in the Continuum. MICROMACHINES 2022; 13:1945. [PMID: 36363965 PMCID: PMC9693007 DOI: 10.3390/mi13111945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 11/02/2022] [Accepted: 11/08/2022] [Indexed: 06/16/2023]
Abstract
In this paper, we combine the dielectric metasurface with monolayer graphene to realize a high quality(Q)-factor quasi-BIC-based optical modulator, and the corresponding modulation performances are investigated by using the finite-difference time-domain (FDTD) method, which can be well fitting by the Fano formula based on the temporal couple-mode theory. The results demonstrate that bound states in the continuum (BIC) will turn into the quasi-BIC with high Q-factor by breaking the symmetry of every unit of the metasurface. Meanwhile, the amplitude and bandwidth of transmission based on the quasi-BIC mode can be efficiently adjusted by changing the Fermi energy (EF) of monolayer graphene, and the maximum difference in transmission up to 0.92 is achieved. Moreover, we also discuss the influence of the asymmetry degree to further investigate the modulation effect of graphene on the quasi-BIC mode.
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Affiliation(s)
- Chaolong Li
- School of Science, East China Jiaotong University, Nanchang 330013, China
| | - Hongbo Cheng
- Science and Technology on Aerospace Chemical Power Laboratory, Hubei Institute of Aerospace Chemotechnology, Xiangyang 441003, China
| | - Xin Luo
- School of Science, East China Jiaotong University, Nanchang 330013, China
- Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China
| | - Ziqiang Cheng
- School of Science, East China Jiaotong University, Nanchang 330013, China
| | - Xiang Zhai
- Key Laboratory for Micro-Nano Optoelectronic Devices of Ministry of Education, School of Physics and Electronics, Hunan University, Changsha 410082, China
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Sang D, Xu M, An Q, Fu Y. Broadband transparent and high-Q resonant polarization meta-grating enabled by a non-local geometric-phase metasurface. OPTICS EXPRESS 2022; 30:26664-26675. [PMID: 36236854 DOI: 10.1364/oe.462248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 06/27/2022] [Indexed: 06/16/2023]
Abstract
Spatial wavefront control and high-Q spectral filtering are both of great importance for various optical applications, such as eye-tracking for eyewear, planar optical modulators, and optical sensing. However, it is a great challenge to simultaneously satisfy these two functionalities in a metasurface due to the inevitable conflicts of local and non-local modes, where local modes of a single meta-atom manipulate the wavefront in a broadband range, while non-local collective modes of extended meta-atoms only support high-Q resonances at certain characteristic wavelengths. Here, we demonstrate a low-contrast dielectric non-local meta-grating that provides both spatial and spectral control of light in a broadband range of 700-1600 nm, offering elaborate wavefront shaping only for narrow-band resonances. Such counterintuitive functionality is supported by spatially tailored dark modes (quasi-bound states in the continuum) encoding with spatially varying geometric phases, while low-contrast dielectric provides broadband non-resonant transmission. Moreover, a broadband transparent polarization meta-grating with two resonance wavelengths is presented. Non-local geometric-phase metasurfaces open an exciting avenue for wavefront shaping and spectral manipulation, and may have potential applications in sensing, lasing, and spectral filtering.
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