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Lor C, Phon R, Lim S. Reconfigurable transmissive metasurface with a combination of scissor and rotation actuators for independently controlling beam scanning and polarization conversion. MICROSYSTEMS & NANOENGINEERING 2024; 10:40. [PMID: 38523656 PMCID: PMC10958044 DOI: 10.1038/s41378-024-00671-y] [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: 07/11/2023] [Revised: 11/07/2023] [Accepted: 11/27/2023] [Indexed: 03/26/2024]
Abstract
Polarization conversion and beam scanning metasurfaces are commonly used to reduce polarization mismatch and direct electromagnetic waves in a specific direction to improve the strength of a wireless signal. However, identifying suitable active and mechanically reconfigurable metasurfaces for polarization conversion and beam scanning is a considerable challenge, and the reported metasurfaces have narrow scanning ranges, are expensive, and cannot be independently controlled. In this paper, we propose a reconfigurable transmissive metasurface combined with a scissor and rotation actuator for independently controlling beam scanning and polarization conversion functions. The metasurface is constructed with rotatable unit cells (UCs) that can switch the polarization state between right-handed (RHCP) and left-handed circular polarization (LHCP) by flipping the UCs to reverse their phase variation. Moreover, independent beam scanning is achieved using the scissor actuator to linearly change the distance between the UCs. Numerical and experimental results confirm that the proposed metasurface can perform beam scanning in the range of 28° for both the positive and negative regions of a radiation pattern (RHCP and LHCP beams) at an operational frequency of 10.5 GHz.
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Affiliation(s)
- Chhunheng Lor
- Intelligent Semiconductor Engineering, Chung-Ang University, Heukseok-Dong, Dongjak-Gu, Seoul, 06974 Republic of Korea
| | - Ratanak Phon
- School of Electrical and Electronic Engineering, Chung-Ang University, Heukseok-Dong, Dongjak-Gu, Seoul, 06974 Republic of Korea
| | - Sungjoon Lim
- Intelligent Semiconductor Engineering, Chung-Ang University, Heukseok-Dong, Dongjak-Gu, Seoul, 06974 Republic of Korea
- School of Electrical and Electronic Engineering, Chung-Ang University, Heukseok-Dong, Dongjak-Gu, Seoul, 06974 Republic of Korea
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2
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Shi Y, Wan S, Dai C, Wang Z, Li Z, Li Z. On-Chip Meta-Optics for Engineering Arbitrary Trajectories with Longitudinal Polarization Variation. NANO LETTERS 2024; 24:2063-2070. [PMID: 38299886 DOI: 10.1021/acs.nanolett.3c04739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
On-chip integrated meta-optics promise to achieve high-performance and compact integrated photonic devices. To arbitrarily engineer the optical trajectory along the propagation path in an on-chip integrated scheme is of significance in fundamental physics and various emerging applications. Here, we experimentally demonstrate an on-chip metasurface integrated on a waveguide to enable predefined arbitrary optical trajectories in the visible regime. By transformation of the transverse phase to generate longitudinal mapping, the guided waves are extracted and molded into any different optical trajectories (parabola, hyperbola, and cosine). More intriguingly, predefined polarization states with longitudinal variation are also successfully imparted along the trajectory. Owing to the on-chip propagation scheme, the trajectories are uniquely free from zero-order diffraction interference, naturally having a higher signal-to-noise ratio beyond conventional free-space forms. Overall, such on-chip optical trajectory engineering allows for miniaturized integration and can find paths in potential applications of complex optical manipulation, advanced laser fabrication, and microscopic imaging.
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Affiliation(s)
- Yangyang Shi
- Electronic Information School, Wuhan University, Wuhan 430072, China
| | - Shuai Wan
- Electronic Information School, Wuhan University, Wuhan 430072, China
| | - Chenjie Dai
- Electronic Information School, Wuhan University, Wuhan 430072, China
| | - Zejing Wang
- Electronic Information School, Wuhan University, Wuhan 430072, China
| | - Zhe Li
- Electronic Information School, Wuhan University, Wuhan 430072, China
| | - Zhongyang Li
- Electronic Information School, Wuhan University, Wuhan 430072, China
- Wuhan Institute of Quantum Technology, Wuhan 430206, China
- School of Microelectronics, Wuhan University, Wuhan 430072, China
- Suzhou Institute of Wuhan University, Suzhou 215123, China
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3
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Zhang X, Han L, Wu X, Du J, Xin Y, Wei B, Liu S, Li P, Zhao J. Spin-orbit coupling induced polarization transform in the autofocusing of ring Airy beams with hybrid polarizations. OPTICS EXPRESS 2023; 31:44019-44027. [PMID: 38178483 DOI: 10.1364/oe.506967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 11/27/2023] [Indexed: 01/06/2024]
Abstract
Manipulating polarization is of significance for the application of light. Spin-orbit coupling provides a prominent pathway for manipulating the polarization of light field but generally requires tight focusing conditions or anisotropic media. In this paper, we construct ring Airy beams with hybrid polarizations and reveal the controllable polarization transforms in their autofocusing dynamics by manipulating concomitant spin-orbit coupling in free space. The numerical and experimental results show that the polarization transform is dependent on the azimuthal orders of amplitude and vortex phases of two spin constituents of ring Airy beams, that the focal spots present pure linear polarization whose orientation is determined by the initial phase when the vortex phase topological charge is equal to the amplitude angular factor, otherwise, the focal fields present cylindrical vector polarizations whose orders depend on the difference of amplitude angular orders and topological charges. Our work provides new insights for studying spin-orbit interactions and the depolarization of complex polarization.
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Ge S, Li X, Liu Z, Zhao J, Wang W, Li S, Zhang W. Polarization-multiplexed metasurface enabled tri-functional imaging. OPTICS LETTERS 2023; 48:5683-5686. [PMID: 37910733 DOI: 10.1364/ol.502632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 10/08/2023] [Indexed: 11/03/2023]
Abstract
Diffraction-limited focusing imaging, edge-enhanced imaging, and long depth of focus imaging offer crucial technical capabilities for applications such as biological microscopy and surface topography detection. To conveniently and quickly realize the microscopy imaging of different functions, the multifunctional integrated system of microscopy imaging has become an increasingly important research direction. However, conventional microscopes necessitate bulky optical components to switch between these functionalities, suffering from the system's complexity and unstability. Hence, solving the problem of integrating multiple functions within an optical system is a pressing need. In this work, we present an approach using a polarization-multiplexed tri-functional metasurface, capable of realizing the aforementioned imaging functions simply by changing the polarization state of the input and output light, enhancing the system structure's compactness and flexibility. This work offers a new avenue for multifunctional imaging, with potential applications in biomedicine and microscopy imaging.
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Tan Y, Chen J, Cheng J, Mei W, Zhang Z, Ling X. Role of beam parameters in the spin-orbit interactions of light. OPTICS EXPRESS 2023; 31:34300-34312. [PMID: 37859190 DOI: 10.1364/oe.502549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 09/14/2023] [Indexed: 10/21/2023]
Abstract
We employ a full-wave theory to systematically investigate two types of spin-orbit interactions and their topological phase transitions for various light beams (e.g., Laguerre-Gaussian, Bessel, and Bessel-Gaussian beams) at optical interfaces, and explore the influence of beam parameters on the spin-Hall shift. It is demonstrated that at small-angle incidence, the beam profile and spin-Hall shift are significantly affected by the beam parameters (e.g., waist radius, radial index, azimuthal index, and cone angle), whereas at large-angle incidence, only the azimuthal index has a salient influence on them. We further find that the Bessel beam and the Gaussian-modulated ones (i.e., Laguerre-Gaussian and Bessel-Gaussian beams) have similar topological phase transition phenomena but different shifts. Quantitative dependences of beam parameters, such as waist radius, radial index, azimuthal index, and cone angle, on the shift are also presented. Our findings offer alternative degrees of freedom in controlling the topological phase transitions of light, and suggest a valuable insight for exploring the applications of SOIs of diverse light fields.
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Kovalev AA, Kotlyar VV, Nalimov AG. Spin Hall Effect in Paraxial Vectorial Light Beams with an Infinite Number of Polarization Singularities. MICROMACHINES 2023; 14:1470. [PMID: 37512780 PMCID: PMC10384323 DOI: 10.3390/mi14071470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/13/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023]
Abstract
Elements of micromachines can be driven by light, including structured light with phase and/or polarization singularities. We investigate here a paraxial vector Gaussian beam with an infinite number of polarization singularities residing evenly on a straight line. The intensity distribution is derived analytically and the polarization singularities are shown to exist only in the initial plane and in the far field. The azimuthal angle of the polarization singularities is shown to increase in the far field by π/2. We obtain the longitudinal component of the spin angular momentum (SAM) density and show that it is independent of the azimuthal angle of the polarization singularities. Upon propagation in free space, an infinite number of C-points is generated, where polarization is circular. We show that the SAM density distribution has a shape of four spots, two with left and two with right elliptic polarization. The distance to the transverse plane with the maximal SAM density decreases with decreasing distance between the polarization singularities in the initial plane. Generating such alternating areas with positive and negative SAM density, despite linear polarization in the initial plane, manifests the optical spin Hall effect. Application areas of the obtained results include designing micromachines with optically driven elements.
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Affiliation(s)
- Alexey A Kovalev
- Image Processing Systems Institute of the RAS-Branch of FSRC "Crystallography & Photonics" of the RAS, 151 Molodogvardeyskaya St., 443001 Samara, Russia
- Technical Cybernetics Department, Samara National Research University, 34 Moskovskoe Shosse, 443086 Samara, Russia
| | - Victor V Kotlyar
- Image Processing Systems Institute of the RAS-Branch of FSRC "Crystallography & Photonics" of the RAS, 151 Molodogvardeyskaya St., 443001 Samara, Russia
- Technical Cybernetics Department, Samara National Research University, 34 Moskovskoe Shosse, 443086 Samara, Russia
| | - Anton G Nalimov
- Image Processing Systems Institute of the RAS-Branch of FSRC "Crystallography & Photonics" of the RAS, 151 Molodogvardeyskaya St., 443001 Samara, Russia
- Technical Cybernetics Department, Samara National Research University, 34 Moskovskoe Shosse, 443086 Samara, Russia
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Kovalev AA, Kotlyar VV, Stafeev SS. Spin Hall Effect in the Paraxial Light Beams with Multiple Polarization Singularities. MICROMACHINES 2023; 14:777. [PMID: 37421010 DOI: 10.3390/mi14040777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 03/27/2023] [Accepted: 03/29/2023] [Indexed: 07/09/2023]
Abstract
Elements of micromachines can be driven by light, including structured light with phase and/or polarization singularities. We investigate a paraxial vectorial Gaussian beam with multiple polarization singularities residing on a circle. Such a beam is a superposition of a cylindrically polarized Laguerre-Gaussian beam with a linearly polarized Gaussian beam. We demonstrate that, despite linear polarization in the initial plane, on propagation in space, alternating areas are generated with a spin angular momentum (SAM) density of opposite sign, that manifest about the spin Hall effect. We derive that in each transverse plane, maximal SAM magnitude is on a certain-radius circle. We obtain an approximate expression for the distance to the transverse plane with the maximal SAM density. Besides, we define the singularities circle radius, for which the achievable SAM density is maximal. It turns out that in this case the energies of the Laguerre-Gaussian and of the Gaussian beams are equal. We obtain an expression for the orbital angular momentum density and find that it is equal to the SAM density, multiplied by -m/2 with m being the order of the Laguerre-Gaussian beam, equal to the number of the polarization singularities. We consider an analogy with plane waves and find that the spin Hall affect arises due to the different divergence between the linearly polarized Gaussian beam and cylindrically polarized Laguerre-Gaussian beam. Application areas of the obtained results are designing micromachines with optically driven elements.
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Affiliation(s)
- Alexey A Kovalev
- Image Processing Systems Institute of the RAS-Branch of FSRC "Crystallography & Photonics" of the RAS, 151 Molodogvardeyskaya St., 443001 Samara, Russia
- Samara National Research University, 34 Moskovskoe Shosse, 443086 Samara, Russia
| | - Victor V Kotlyar
- Image Processing Systems Institute of the RAS-Branch of FSRC "Crystallography & Photonics" of the RAS, 151 Molodogvardeyskaya St., 443001 Samara, Russia
- Samara National Research University, 34 Moskovskoe Shosse, 443086 Samara, Russia
| | - Sergey S Stafeev
- Image Processing Systems Institute of the RAS-Branch of FSRC "Crystallography & Photonics" of the RAS, 151 Molodogvardeyskaya St., 443001 Samara, Russia
- Samara National Research University, 34 Moskovskoe Shosse, 443086 Samara, Russia
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Yang H, He P, Ou K, Hu Y, Jiang Y, Ou X, Jia H, Xie Z, Yuan X, Duan H. Angular momentum holography via a minimalist metasurface for optical nested encryption. LIGHT, SCIENCE & APPLICATIONS 2023; 12:79. [PMID: 36977672 PMCID: PMC10050323 DOI: 10.1038/s41377-023-01125-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 02/23/2023] [Accepted: 03/06/2023] [Indexed: 05/28/2023]
Abstract
Metasurfaces can perform high-performance multi-functional integration by manipulating the abundant physical dimensions of light, demonstrating great potential in high-capacity information technologies. The orbital angular momentum (OAM) and spin angular momentum (SAM) dimensions have been respectively explored as the independent carrier for information multiplexing. However, fully managing these two intrinsic properties in information multiplexing remains elusive. Here, we propose the concept of angular momentum (AM) holography which can fully synergize these two fundamental dimensions to act as the information carrier, via a single-layer, non-interleaved metasurface. The underlying mechanism relies on independently controlling the two spin eigenstates and arbitrary overlaying them in each operation channel, thereby spatially modulating the resulting waveform at will. As a proof of concept, we demonstrate an AM meta-hologram allowing the reconstruction of two sets of holographic images, i.e., the spin-orbital locked and the spin-superimposed ones. Remarkably, leveraging the designed dual-functional AM meta-hologram, we demonstrate a novel optical nested encryption scheme, which is able to achieve parallel information transmission with ultra-high capacity and security. Our work opens a new avenue for optionally manipulating the AM, holding promising applications in the fields of optical communication, information security and quantum science.
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Affiliation(s)
- Hui Yang
- National Research Center for High-Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082, China
- Nanophotonics Research Center, Shenzhen Key Laboratory of Micro-scale Optical Information Technology, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, 518060,, Guangdong, China
| | - Peng He
- National Research Center for High-Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082, China
| | - Kai Ou
- Institute of Precision Optical Engineering, School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Yueqiang Hu
- National Research Center for High-Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082, China.
- Greater Bay Area Institute for Innovation, Hunan University, Guangzhou, 511300,, Guangdong Province, China.
| | - Yuting Jiang
- National Research Center for High-Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082, China
| | - Xiangnian Ou
- National Research Center for High-Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082, China
| | - Honghui Jia
- National Research Center for High-Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082, China
- Greater Bay Area Institute for Innovation, Hunan University, Guangzhou, 511300,, Guangdong Province, China
| | - Zhenwei Xie
- Nanophotonics Research Center, Shenzhen Key Laboratory of Micro-scale Optical Information Technology, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, 518060,, Guangdong, China.
| | - Xiaocong Yuan
- Nanophotonics Research Center, Shenzhen Key Laboratory of Micro-scale Optical Information Technology, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, 518060,, Guangdong, China
| | - Huigao Duan
- National Research Center for High-Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, Changsha, 410082, China.
- Greater Bay Area Institute for Innovation, Hunan University, Guangzhou, 511300,, Guangdong Province, China.
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Zhang J, Zhou S, Dai X, Huang M, Yu X. All-optical image edge detection based on the two-dimensional photonic spin Hall effect in anisotropic metamaterial. OPTICS EXPRESS 2023; 31:6062-6075. [PMID: 36823872 DOI: 10.1364/oe.476492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 01/12/2023] [Indexed: 06/18/2023]
Abstract
Optical image processing based on the photonic spin Hall effect (SHE) has been gaining significant attention as a convenient and an accurate way for image edge detection. However, the recent edge imaging techniques depending on optical differentiation is mainly achieved by modulation of one-dimensional photonic SHE. Here, we theoretically predict the two-dimensional photonic SHE in the anisotropic metamaterial, and find that its longitudinal and transverse displacements exhibit spin-dependent property at filling factors with increasing incidence angle. As the transverse and in-plane displacements induced by the photonic SHE can be controlled by the filling factor of the crystal structure, the optical axis angle, and the incident angle, this intrinsical effect can be used to realize a tunable edge imaging. Interestingly, by changing the optical axis of the anisotropic metamaterial, the in-plane displacements are equal to the transverse displacements for a certain filling factor and the corresponding incident angle. Therefore, we propose a two-dimensional image edge detection method based on the photonic SHE in anisotropic metamaterial. Further numerical results validate the theoretical proposal.
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Cao W, Lu Q, Zhou X, Shu W. Quadratic spin Hall effect of light due to phase change. OPTICS LETTERS 2023; 48:371-374. [PMID: 36638460 DOI: 10.1364/ol.480958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
The spin Hall effect (SHE) of light has brought important applications, but the involved spin states only split in one direction. Here we employ an accurate three-dimensional model of light to show that the SHE generally exhibits quadratic spin splitting, i.e., both vertical and horizontal splitting, in the presence of a fast phase change of reflection. Further, we disclose that the two splittings are actually different from each other, and that they originate from the vertical and horizontal spin momentum flows, respectively, owing to the spatial gradient of polarization in the individual direction. Finally, it is found that by tuning the incident angle and polarization of light, one can manipulate the quadratic SHE so as to realize a variety of spin splittings, such as unbalanced quadratic splitting and off-center splitting of spin states.
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Li H, Xu W, Shu W. Topological spatial differentiators upon reflection of the normally incident light. OPTICS LETTERS 2022; 47:5425-5428. [PMID: 36240380 DOI: 10.1364/ol.473999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
We theoretically propose topological spatial differentiators by the normal-incidence reflection of light. Firstly, a three-dimensional propagation model is established for the light normally incident on the interface between two media. It is found that due to the spin-orbit interaction of light, a given circularly polarized light always induces oppositely polarized light carrying a topological charge, so the two intrinsic spin components are separated radially or azimuthally. Moreover, the normally reflected fields are approximately proportional to two kinds of second-order spatial differentiations of the input circularly and linearly polarized fields. Further results applying to the two-dimensional image processing for edge detection validate the two topological spatial differentiators.
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Luo Z, Zou J, Zhao E, Rao Y, Wu ST. Correcting the wavelength-induced phase deviation of Pancharatnam-Berry lenses. OPTICS EXPRESS 2022; 30:36644-36650. [PMID: 36258588 DOI: 10.1364/oe.473679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 09/07/2022] [Indexed: 06/16/2023]
Abstract
Liquid-crystal-based Pancharatnam-Berry optical elements are widely used in virtual reality and augmented reality. However, the mismatch between exposure wavelength and operating wavelength leads to an undesirable phase deviation to the lenses, which in turn causes severe aberration especially when the f-number is small. To overcome the mismatched wavelength problem and to obtain a nearly ideal lens phase profile, a new exposure method using two template lenses with different focal lengths is proposed and experimentally validated. Our results indicate that such a lens indeed exhibits a better imaging performance than that fabricated by traditional interference method.
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