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Gokkavas M, Gundogdu TF, Ozbay E, Serebryannikov AE. Few-layer bifunctional metasurfaces enabling asymmetric and symmetric polarization-plane rotation at the subwavelength scale. Sci Rep 2024; 14:13636. [PMID: 38871798 DOI: 10.1038/s41598-024-62073-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 05/13/2024] [Indexed: 06/15/2024] Open
Abstract
We introduce and numerically validate the concept of few-layer bifunctional metasurfaces comprising two arrays of quasiplanar subwavelength resonators and a middle grid (array of rectangular holes) that offer both symmetric and asymmetric transmissions connected, respectively, with symmetric and asymmetric polarization-plane rotation functionalities. The proposed structures are thinner than λ / 7 and free of diffractions. Usually, the structure's symmetry or asymmetry, i.e. unbroken or broken spatial inversion symmetries, are considered for metasurfaces as prerequisites of the capability of symmetric or asymmetric conversion of linearly polarized waves, respectively. Due to the achieved adjustment of the resonances enabling the rotation of the polarization plane simultaneously for both orthogonal polarizations of the incident wave, the symmetric polarization-plane rotation functionality can be obtained within one subwavelength band, whereas the asymmetric polarization-plane rotation functionality associated with the asymmetric transmission is obtained within another subwavelength band. This combination of the functionalities in one subdiffraction structure is possible due to the optimal choice of the grid parameters, since they may strongly affect the coupling between the two resonator arrays. Although normal incidence is required for the targeted bifunctionality, the variations of the incidence angle can also be exploited for the enrichment of the overall functional capability. Variations of the polarization angle give another important degree of freedom. The connection between the polarization-angle dependence of cross-polarized transmission and capability of symmetric and asymmetric polarization-plane rotation functionalities is highlighted. The feasible designs of the bifunctional metasurfaces are discussed.
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Affiliation(s)
- Mutlu Gokkavas
- Nanotechnology Research Center (NANOTAM), Bilkent University, 06800, Ankara, Turkey
| | - T F Gundogdu
- Nanotechnology Research Center (NANOTAM), Bilkent University, 06800, Ankara, Turkey
| | - Ekmel Ozbay
- Nanotechnology Research Center (NANOTAM), Bilkent University, 06800, Ankara, Turkey.
- Department of Physics, Department of Electrical Engineering, National Institute of Materials Sciences and Nanotechnology (UNAM), Bilkent University, 06800, Ankara, Turkey.
| | - Andriy E Serebryannikov
- Division of Physics of Nanostructures, ISQI, Faculty of Physics, Adam Mickiewicz University, 61-614, Poznan, Poland.
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2
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Fu T, Zhang RY, Jia S, Chan CT, Wang S. Near-Field Spin Chern Number Quantized by Real-Space Topology of Optical Structures. PHYSICAL REVIEW LETTERS 2024; 132:233801. [PMID: 38905648 DOI: 10.1103/physrevlett.132.233801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 05/01/2024] [Indexed: 06/23/2024]
Abstract
The Chern number has been widely used to describe the topological properties of periodic structures in momentum space. Here, we introduce a real-space spin Chern number for the optical near fields of finite-sized structures. This new spin Chern number is intrinsically quantized and equal to the structure's Euler characteristic. The relationship is robust against continuous deformation of the structure's geometry and is irrelevant to the specific material constituents or external excitation. Our Letter enriches topological physics by extending the Chern number to real space, opening exciting possibilities for exploring the real-space topological properties of light.
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3
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Jiang Y, Wu J, Ge R, Zhang Z. Observation of the spin Hall effect of light by a single-photon detector. OPTICS LETTERS 2024; 49:3014-3017. [PMID: 38824316 DOI: 10.1364/ol.522132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 04/29/2024] [Indexed: 06/03/2024]
Abstract
We use a single-photon detector to detect the spin Hall effect of light (SHEL) of a quasi-single-photon beam obtained in this Letter. The physics of the spin Hall effect and its quantum weak measurement method with a dimensionless pointer are elucidated through particle number representation. Our weak measurement scheme obviates the necessity of high-resolution single-photon array detectors. Consequently, we have successfully observed the spin Hall effect within a 20 ns temporal window using a position-resolution-independent single-photon detector with remarkably low-noise levels. The weak measurement of the dimensionless pointer presented in this Letter boosts both the detection accuracy and the response speed of the photonics spin Hall effect, thereby contributing significantly to fundamental theoretical research in spin photonics and precise measurements of physical property parameters.
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4
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Du W, Hu L, Xia J, Zhang L, Li S, Kuai Y, Cao Z, Xu F, Liu Y, Zhou K, Xie K, Yu B, Raposo EP, Gomes ASL, Hu Z. Observation of the photonic Hall effect and photonic magnetoresistance in random lasers. Nat Commun 2024; 15:4589. [PMID: 38816395 PMCID: PMC11139889 DOI: 10.1038/s41467-024-48942-6] [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: 09/26/2023] [Accepted: 05/17/2024] [Indexed: 06/01/2024] Open
Abstract
Modulation of scattering in random lasers (RLs) by magnetic fields has attracted much attention due to its rich physical insights. We fabricate magnetic gain polymer optical fiber to generate RLs. From macroscopic experimental phenomena, with the increase of the magnetic field strength, the magnetic transverse photocurrent exists in disordered multiple scattering of RLs and the emission intensity of RLs decreases, which is the experimental observation of photonic Hall effect (PHE) and photonic magnetoresistance (PMR) in RLs. At the microscopic level, based on the field dependence theory of magnetic disorder in scattered nanoparticles and the replica symmetry breaking theory, the magnetic-induced transverse diffusion of photons reduces the scattering disorder, and then decreases the intensity fluctuation disorder of RLs. Our work establishes a connection between the above two effects and RLs, visualizes the influence of magnetic field on RL scattering at the microscopic level, which is crucial for the design of RLs.
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Affiliation(s)
- Wenyu Du
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui University, Hefei, 230601, China
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, Hefei, 230601, China
- School of Physics and Opto-electronics Engineering, Anhui University, Hefei, 230601, China
| | - Lei Hu
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui University, Hefei, 230601, China
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, Hefei, 230601, China
| | - Jiangying Xia
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui University, Hefei, 230601, China
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, Hefei, 230601, China
| | - Lin Zhang
- Aston Institute of Photonic Technologies, Aston University, Birmingham, B4 7ET, UK
| | - Siqi Li
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui University, Hefei, 230601, China
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, Hefei, 230601, China
- School of Physics and Opto-electronics Engineering, Anhui University, Hefei, 230601, China
| | - Yan Kuai
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui University, Hefei, 230601, China
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, Hefei, 230601, China
| | - Zhigang Cao
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui University, Hefei, 230601, China
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, Hefei, 230601, China
- School of Physics and Opto-electronics Engineering, Anhui University, Hefei, 230601, China
| | - Feng Xu
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, Hefei, 230601, China
- School of Physics and Opto-electronics Engineering, Anhui University, Hefei, 230601, China
| | - Yu Liu
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui University, Hefei, 230601, China
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, Hefei, 230601, China
- School of Physics and Opto-electronics Engineering, Anhui University, Hefei, 230601, China
| | - Kaiming Zhou
- Aston Institute of Photonic Technologies, Aston University, Birmingham, B4 7ET, UK
| | - Kang Xie
- School of Opto-Electronic Engineering, Zaozhuang University, Zaozhuang, 277160, Shandong, China
| | - Benli Yu
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui University, Hefei, 230601, China
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, Hefei, 230601, China
- School of Physics and Opto-electronics Engineering, Anhui University, Hefei, 230601, China
| | - Ernesto P Raposo
- Laboratório de Física Teórica e Computacional, Departamento de Física, Universidade Federal de Pernambuco, 50670-901, Recife, PE, Brazil
| | - Anderson S L Gomes
- Departamento de Física, Universidade Federal de Pernambuco, 50670-901, Recife, PE, Brazil
| | - Zhijia Hu
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui University, Hefei, 230601, China.
- Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, Hefei, 230601, China.
- School of Physics and Opto-electronics Engineering, Anhui University, Hefei, 230601, China.
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5
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Zou HY, Ge Y, Zhao KQ, Lu YJ, Si QR, Yuan SQ, Chen H, Sun HX, Yang Y, Zhang B. Acoustic Metagrating Holograms. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2401738. [PMID: 38771624 DOI: 10.1002/adma.202401738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 05/07/2024] [Indexed: 05/22/2024]
Abstract
Metasurface holograms represent a common category of metasurface devices that utilize in-plane phase gradients to shape wavefronts, forming holographic images through the application of the generalized Snell's law (GSL). While conventional metasurfaces focus solely on phase gradients, metagratings, which incorporate higher-order wave diffraction, further expand the GSL's generality. Recent advances in certain acoustic metagratings demonstrate an updated GSL extension capable of reversing anomalous transmission and reflection, whose reversal is characterized by the parity of the number of wave propagation trips through the metagrating. However, the current extension of GSL remains limited to 1D metagratings, unable to access 2D holographic images in 3D spaces. Here, the GSL extension to 2D metagratings for manipulating waves within 3D spaces is investigated. Through this analysis, a series of acoustic metagrating holograms is experimentally demonstrated. These holographic images exhibit the unique ability to switch between transmission and reflection types independently. This study introduces an additional dimension to modern holography design and metasurface wavefront manipulation.
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Affiliation(s)
- Hong-Yu Zou
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Yong Ge
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Ke-Qi Zhao
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Yu-Jing Lu
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Qiao-Rui Si
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Shou-Qi Yuan
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Hongsheng Chen
- Interdisciplinary Center for Quantum Information, State Key Lab. of Modern Optical Instrumentation, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, 310027, China
- ZJU-Hangzhou Global Science and Technology Innovation Center, Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, ZJU-UIUC Institute, Zhejiang University, Hangzhou, 310027, China
| | - Hong-Xiang Sun
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, 212013, China
- State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yihao Yang
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, 212013, China
- ZJU-Hangzhou Global Science and Technology Innovation Center, Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, ZJU-UIUC Institute, Zhejiang University, Hangzhou, 310027, China
| | - Baile Zhang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
- Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
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6
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Wang B, Wei R, Shi H, Bao Y. Dynamic Spatial-Selective Metasurface with Multiple-Beam Interference. NANO LETTERS 2024; 24:5886-5893. [PMID: 38687301 DOI: 10.1021/acs.nanolett.4c01254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
The emergence of the metasurface has provided a versatile platform for the manipulation of light at the nanoscale. Recent research in metasurfaces has explored a plethora of dynamic control and switching of multifunctionalities, paving the way for innovative applications in fields such as imaging, sensing, and communication. However, current dynamic multifunctional metasurfaces face challenges in terms of functional scalability and selective activation. In this work, we introduce and experimentally demonstrate a strategy that utilizes multiple plane waves to create arbitrary periodic patterns on the metasurface, thus enabling the dynamic and arbitrary spatial-selective activation of its embedded multiplexed functionalities. Furthermore, our strategy facilitates dynamic light control through mechanical translation, as demonstrated by a high-speed, dynamically switchable beam deflection scenario. Our method effectively overcomes the limitations associated with traditional spatially multiplexing techniques, offering greater flexibility and selectivity for dynamic control in multifunctional metasurfaces.
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Affiliation(s)
- Boyou Wang
- Guangdong Provincial Key Laboratory of Nanophotonic Manipulation, Institute of Nanophotonics, College of Physics & Optoelectronic Engineering, Jinan University, Guangzhou 511443, China
| | - Rui Wei
- Guangdong Provincial Key Laboratory of Nanophotonic Manipulation, Institute of Nanophotonics, College of Physics & Optoelectronic Engineering, Jinan University, Guangzhou 511443, China
| | - Hongsheng Shi
- Guangdong Provincial Key Laboratory of Nanophotonic Manipulation, Institute of Nanophotonics, College of Physics & Optoelectronic Engineering, Jinan University, Guangzhou 511443, China
| | - Yanjun Bao
- Guangdong Provincial Key Laboratory of Nanophotonic Manipulation, Institute of Nanophotonics, College of Physics & Optoelectronic Engineering, Jinan University, Guangzhou 511443, China
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7
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Lee G, Choi W, Ji B, Kim M, Rho J. Timoshenko-Ehrenfest Beam-Based Reconfigurable Elastic Metasurfaces for Multifunctional Wave Manipulation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2400090. [PMID: 38482735 PMCID: PMC11109653 DOI: 10.1002/advs.202400090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 02/19/2024] [Indexed: 05/23/2024]
Abstract
Herein, a Timoshenko-Ehrenfest beam-based reconfigurable elastic metasurface is introduced that can perform multifunctional wave phenomena within a single substrate, featuring high transmission in the ultrabroadband frequency range. Conventional elastic metasurfaces are typically limited to specific purposes and frequencies, thereby imposing significant constraints on their practical application. The approach involves assembly-components with various geometries on a substrate for reconfigurability, enabling to easily control and implement multifunctional wave phenomena, including anomalous-refraction, focusing, self-acceleration, and total-reflection. This is the first study on elastic metasurfaces to theoretically analyze the dispersion relation based on the Timoshenko-Ehrenfest beam theory, which considers shear deformations and rotational inertia. The analytical model is validated by demonstrating an excellent agreement with numerical and experimental results. The findings include full-wave harmonic simulations and experimentally visualized fields for measuring various wave modulations. Furthermore, the practicality of the system is verified by significantly enhancing the piezoelectric energy harvesting performance within the focusing configuration. It is believed that the reconfigurable elastic metasurface and analytical model based on the Timoshenko-Ehrenfest beam theory have vast applications such as structural health monitoring, wireless sensing, and Internet of Things.
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Affiliation(s)
- Geon Lee
- Department of Mechanical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
| | - Wonjae Choi
- Intelligent Wave Engineering TeamKorea Research Institute of Standards and Science (KRISS)Daejeon34113Republic of Korea
- Department of Precision MeasurementUniversity of Science and Technology (UST)Daejeon34113Republic of Korea
| | - Bonggyu Ji
- Intelligent Wave Engineering TeamKorea Research Institute of Standards and Science (KRISS)Daejeon34113Republic of Korea
- Korea Automotive Tuning Institute of Safety TechnologyTesting Certification Office, Korea Transportation Safety Authority (KOTSA)Gimcheon39506Republic of Korea
| | - Miso Kim
- School of Advanced Materials Science and EngineeringSungkyunkwan University (SKKU)Suwon16519Republic of Korea
- SKKU Institute of Energy Science and Engineering (SIEST)Sungkyunkwan University (SKKU)Suwon16519Republic of Korea
| | - Junsuk Rho
- Department of Mechanical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
- Department of Chemical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
- Department of Electrical EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
- POSCH‐POSTECH‐RIST Convergence Research Center for Flat Optics and MetaphotonicsPohang37673Republic of Korea
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8
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Lu B, Fu Y, Zhang T, Jin Z, Zang X, Zhu Y. Terahertz metalens for generating multi-polarized focal points and images with uniform intensity distributions. OPTICS LETTERS 2024; 49:2241-2244. [PMID: 38691689 DOI: 10.1364/ol.519605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 03/16/2024] [Indexed: 05/03/2024]
Abstract
Metasurfaces have provided a flexible platform for designing ultracompact metalenses with unusual functionalities. However, traditional multi-foci metalenses are limited to generating circularly polarized (CP) or linearly polarized (LP) focal points, and the intensity distributions are always inhomogeneous/chaotical between the multiple focal points. Here, an inverse design approach is proposed to optimize the in-plane orientation of each meta-atom in a terahertz (THz) multi-foci metalens that can generate multi-polarized focal points with nearly uniform intensity distributions. As a proof-of-principle example, we numerically and experimentally demonstrate an inversely designed metalens for simultaneously generating multiple CP- and LP-based focal points with homogeneous intensity distributions, leading to a multi-polarized image (rather than the holography). Furthermore, the multi-channel and multi-polarized images consisting of multiple focal points with homogeneous intensity distributions are also numerically demonstrated. The unique approach for inversely designing multi-foci metalens that can generate multi-polarized focal points and images with uniform intensity distributions will enable potential applications in imaging and sensing.
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9
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Zhu M, Fu S, Man Z. Time-varying optical spin-orbit Hall effect in tightly focused femtosecond optical field. OPTICS EXPRESS 2024; 32:11715-11725. [PMID: 38571012 DOI: 10.1364/oe.519223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 03/06/2024] [Indexed: 04/05/2024]
Abstract
The spin-orbit Hall effect (HE) is dominated by the law of conservation of angular momentum of a beam and is highly significant in light-matter interactions. The electromagnetic field, phase, topological structure, and spin-orbit HE of an azimuthally polarized vortex pulse beam in a tightly focused system are studied theoretically here. Calculations show that the focal field has ultrafast bright-dark alternating characteristics and a distorted phase distribution. Furthermore, the time evolution of the polarization singularity in the focused light field is explained using Stokes parameters. Importantly, the spin-orbit HE of the pulsed beam is shown to be time-varying in a tightly focused system. This time-varying spin-orbit HE is particularly sensitive to the pulse width and central wavelength. Our method has important applications in particle manipulation.
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Xie L, Zhu J, Ren G, Yang F, Xu L, Dan Y, Zhang Z. Particle nature of the photonic spin Hall effect. OPTICS EXPRESS 2024; 32:9468-9485. [PMID: 38571181 DOI: 10.1364/oe.517460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 02/20/2024] [Indexed: 04/05/2024]
Abstract
It is widely recognized that light exhibits a wave-particle duality. However, the explanation for the photonic spin Hall effect (PSHE) primarily relies on the wave nature of light as dictated by Maxwell's Equations. There is a lack of exploration into the particle nature of light in this regard. In this context, we offer a fresh interpretation of the PSHE from the perspective of particle nature of light. For the out-of-plane PSHE, the spin shifts result from the macroscopic manifestation of the conservation of spin-orbital angular momentum of one photon. For the in-plane PSHE, the spin shifts arise from the spread of in-plane wavevector. Based on the wave nature of light, we also obtain the same spin shifts, confirming the consistency of the wave-particle duality of light. Furthermore, we find that the spin shifts of the PSHE are not the overall displacement of photons with the same handedness, but the outcome of coherent superposition among photons of the same handedness. These discoveries further enhance our comprehension of the fundamental nature of the PSHE.
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11
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Wu HC, Xu HS, Xie LC, Jin L. Edge State, Band Topology, and Time Boundary Effect in the Fine-Grained Categorization of Chern Insulators. PHYSICAL REVIEW LETTERS 2024; 132:083801. [PMID: 38457698 DOI: 10.1103/physrevlett.132.083801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 01/10/2024] [Indexed: 03/10/2024]
Abstract
We predict novel topological phases with broken time-reversal symmetry supporting the coexistence of opposite chiral edge states, which are fundamentally different from the photonic spin-Hall, valley-Hall, and higher-order topological phases. We find a fine-grained categorization of Chern insulators, their band topologies characterized by identical Chern numbers are completely different. Furthermore, we prove that different topologies cause zeros in their Bloch wave function overlaps, which imprint the band gap closing and appear at the degenerate points of topological phase transition. The Bloch wave function overlaps predict the reflection and refraction at a topological time boundary, and the overlap zeros ensure the existence of vanishing revival amplitude at critical times even though different topologies before and after the time boundary have identical Chern numbers. Our findings create new opportunities for topological metamaterials, uncover the topological feature hidden in the time boundary effect as a probe of topology, and open a venue for the exploration of the rich physics originating from the long-range couplings.
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Affiliation(s)
- H C Wu
- School of Physics, Nankai University, Tianjin 300071, China
- School of Physics, Zhengzhou University, Zhengzhou 450001, China
| | - H S Xu
- School of Physics, Nankai University, Tianjin 300071, China
| | - L C Xie
- School of Physics, Nankai University, Tianjin 300071, China
| | - L Jin
- School of Physics, Nankai University, Tianjin 300071, China
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12
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Liang Q, Ma X, Gu C, Ren J, An C, Fu H, Schumacher S, Liao Q. Photochemical Reaction Enabling the Engineering of Photonic Spin-Orbit Coupling in Organic-Crystal Optical Microcavities. J Am Chem Soc 2024; 146:4542-4548. [PMID: 38295022 DOI: 10.1021/jacs.3c11373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
The control and active manipulation of spin-orbit coupling (SOC) in photonic systems are fundamental in the development of modern spin optics and topological photonic devices. Here, we demonstrate the control of an artificial Rashba-Dresselhaus (RD) SOC mediated by photochemical reactions in a microcavity filled with an organic single crystal of photochromic phase-change character. Splitting of the circular polarization components of the optical modes induced by photonic RD SOC is observed experimentally in momentum space. By applying an ultraviolet light beam, we control the spatial molecular orientation through a photochemical reaction, and with that we control the energies of the photonic modes. This way, we realize a reversible conversion of spin splitting of the optical modes with different energies, leading to an optically controlled switching between circularly and linearly polarized optical modes in our device. Our strategy of in situ and reversible engineering of SOC induced by a light field provides a promising approach to actively design and manipulate synthetic gauge fields toward future on-chip integration in photonics and topological photonic devices.
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Affiliation(s)
- Qian Liang
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, China
| | - Xuekai Ma
- Department of Physics and Center for Optoelectronics and Photonics Paderborn (CeOPP), Paderborn University, 33098 Paderborn, Germany
| | - Chunling Gu
- Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China
| | - Jiahuan Ren
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, China
- Hebei Key Laboratory of Optic-Electronic Information Materials, College of Physics Science and Technology, Hebei University, Baoding, 071002, China
| | - Cunbin An
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, China
- School of Materials Science and Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China
| | - Stefan Schumacher
- Department of Physics and Center for Optoelectronics and Photonics Paderborn (CeOPP), Paderborn University, 33098 Paderborn, Germany
- Institute for Photonic Quantum Systems (PhoQS), Paderborn University, 33098 Paderborn, Germany
- Wyant College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, United States
| | - Qing Liao
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, China
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13
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Liu J, Yang Q, Shou Y, Chen S, Shu W, Chen G, Wen S, Luo H. Metasurface-Assisted Quantum Nonlocal Weak-Measurement Microscopy. PHYSICAL REVIEW LETTERS 2024; 132:043601. [PMID: 38335360 DOI: 10.1103/physrevlett.132.043601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 01/02/2024] [Indexed: 02/12/2024]
Abstract
In standard quantum weak measurements, preselection and postselection of quantum states are implemented in the same photon. Here we go beyond this restrictive setting and demonstrate that the preselection and postselection can be performed in two different photons, if the two photons are polarization entangled. The Pancharatnam-Berry phase metasurface is incorporated in the weak measurement system to perform weak coupling between probe wave function and spin observable. By introducing nonlocal weak measurement into the microscopy imaging system, it allows us to remotely switch different microscopy imaging modes of pure-phase objects, including bright-field, differential, and phase reconstruction. Furthermore, we demonstrate that the nonlocal weak-measurement scheme can prevent almost all environmental noise photons from detection and thus achieves a higher image contrast than the standard scheme at a low photon level. Our results provide the possibility to develop a quantum nonlocal weak-measurement microscope for label-free imaging of transparent biological samples.
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Affiliation(s)
- Jiawei Liu
- Laboratory for Spin Photonics, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Qiang Yang
- Laboratory for Spin Photonics, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Yichang Shou
- Laboratory for Spin Photonics, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Shizhen Chen
- Laboratory for Spin Photonics, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Weixing Shu
- Laboratory for Spin Photonics, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Geng Chen
- CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
| | - Shuangchun Wen
- Laboratory for Spin Photonics, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Hailu Luo
- Laboratory for Spin Photonics, School of Physics and Electronics, Hunan University, Changsha 410082, China
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14
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Chen J, Lv J, Zhang R, Si G, Shen M, Wang D. Spin-orbital angular momentum degeneracy breaking in nanoplasmonic metachain. OPTICS LETTERS 2024; 49:198-201. [PMID: 38194527 DOI: 10.1364/ol.506824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 11/26/2023] [Indexed: 01/11/2024]
Abstract
The spin and orbital angular momentum (namely SAM and OAM) mode division provides a promising solution to surmount exhausted available degrees of freedom in conventional optical communications. Nevertheless, SAM and OAM are often subjected to the degeneracy of total angular momentum (AM) because they both have integer variables of quantum eigenstates, which inevitably brings about the shortcomings specific to limited signal channels and multiplexing cross talk. Herein, we present a nanoplasmonic metachain that can discriminatively couple any input SAM and OAM components to an extrinsic orbital AM, corresponding to the chirality and topological charge of incident light. Importantly, the unambiguous measurement has a prominent advantage of detecting the arbitrary AM component rather than the total AM. The miniature metadevice offers the possibility of harnessing AM division on chip or in fiber and holds great promise to delve the spin-orbit interactions for topological photonics and quantum cryptography.
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15
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Zou Y, Jin H, Zhu R, Zhang T. Metasurface Holography with Multiplexing and Reconfigurability. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 14:66. [PMID: 38202521 PMCID: PMC10780441 DOI: 10.3390/nano14010066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/22/2023] [Accepted: 12/23/2023] [Indexed: 01/12/2024]
Abstract
Metasurface holography offers significant advantages, including a broad field of view, minimal noise, and high imaging quality, making it valuable across various optical domains such as 3D displays, VR, and color displays. However, most passive pure-structured metasurface holographic devices face a limitation: once fabricated, as their functionality remains fixed. In recent developments, the introduction of multiplexed and reconfigurable metasurfaces breaks this limitation. Here, the comprehensive progress in holography from single metasurfaces to multiplexed and reconfigurable metasurfaces is reviewed. First, single metasurface holography is briefly introduced. Second, the latest progress in angular momentum multiplexed metasurface holography, including basic characteristics, design strategies, and diverse applications, is discussed. Next, a detailed overview of wavelength-sensitive, angle-sensitive, and polarization-controlled holograms is considered. The recent progress in reconfigurable metasurface holography based on lumped elements is highlighted. Its instant on-site programmability combined with machine learning provides the possibility of realizing movie-like dynamic holographic displays. Finally, we briefly summarize this rapidly growing area of research, proposing future directions and potential applications.
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Affiliation(s)
- Yijun Zou
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310027, China; (Y.Z.); (H.J.); (R.Z.)
| | - Hui Jin
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310027, China; (Y.Z.); (H.J.); (R.Z.)
| | - Rongrong Zhu
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310027, China; (Y.Z.); (H.J.); (R.Z.)
- School of Information and Electrical Engineering, Zhejiang University City College, Hangzhou 310015, China
| | - Ting Zhang
- College of Information Science & Electronic Engineering, Zhejiang Provincial Key Laboratory of Information Processing, Communication and Networking (IPCN), Zhejiang University, Hangzhou 310027, China
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16
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Ui Lee Y, Weon Wu J. Visualization of the optical spin Hall effect in out-of-plane refraction. OPTICS LETTERS 2023; 48:5988-5991. [PMID: 37966770 DOI: 10.1364/ol.507478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 10/25/2023] [Indexed: 11/16/2023]
Abstract
The traditional law of refraction defines the incidence plane as the plane including the incident beam wavevector and the surface normal vector at the interface of two different optical media. The optical spin Hall effect (OSHE) refers to the spin-dependent transverse shift of the refracted beam perpendicular to the incidence plane. In this Letter, we demonstrate that OSHE in out-of-plane refraction can be detected and visualized in the far-field, even at small and normal incidence angles. The extent of spin-dependent photon spatial separation induced by anomalous refraction can be customized by manipulating the 2D additive momentum from the metasurface. Experimental visualization of the OSHE confirms the existence of a new, to the best of our knowledge, plane to describe the OSHE of the refracted beam outside the incidence plane.
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17
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Nayak JK, Suchiang H, Ray SK, Guchhait S, Banerjee A, Gupta SD, Ghosh N. Spin-Direction-Spin Coupling of Quasiguided Modes in Plasmonic Crystals. PHYSICAL REVIEW LETTERS 2023; 131:193803. [PMID: 38000433 DOI: 10.1103/physrevlett.131.193803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 09/25/2023] [Indexed: 11/26/2023]
Abstract
We report an unusual spin-direction-spin coupling phenomenon of light using the leaky quasiguided modes of a waveguided plasmonic crystal. This is demonstrated as simultaneous input spin-dependent directional guiding of waves (spin-direction coupling) and wave-vector-dependent spin acquisition (direction-spin coupling) of the scattered light. These effects, manifested as the forward and the inverse spin Hall effect of light in the far field, and other accompanying spin-orbit interaction effects are observed and analyzed using a momentum (k) domain polarization Mueller matrix. Resonance-enabled enhancement of these effects is also demonstrated by utilizing the spectral Fano resonance of the hybridized modes. The fundamental origin and the unconventional manifestation of the spin-direction-spin coupling phenomenon from a relatively simple system, ability to probe and interpret the resulting spin-orbit phenomena in the far field through momentum-domain polarization analysis, and their regulated control in plasmonic-photonic crystals open up exciting avenues in spin-orbit-photonic research.
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Affiliation(s)
- Jeeban Kumar Nayak
- Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, India, 741246
| | - Harley Suchiang
- Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, India, 741246
| | - Subir Kumar Ray
- Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, India, 741246
| | - Shyamal Guchhait
- Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, India, 741246
| | - Ayan Banerjee
- Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, India, 741246
| | - Subhasish Dutta Gupta
- Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, India, 741246
- Tata Centre for Interdisciplinary Sciences, TIFRH, Hyderabad 500107, India
| | - Nirmalya Ghosh
- Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, India, 741246
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18
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Wang HP, Cao DM, Pang XY, Zhang XH, Wang SY, Hou WY, Nie CC, Li YB. Inverse design of metasurfaces with customized transmission characteristics of frequency band based on generative adversarial networks. OPTICS EXPRESS 2023; 31:37763-37777. [PMID: 38017899 DOI: 10.1364/oe.503139] [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: 10/15/2023] [Indexed: 11/30/2023]
Abstract
In recent years, deep learning (DL) has demonstrated significant potential in the inverse design of metasurfaces, and the generation of metasurfaces with customized transmission characteristics of frequency band remains a challenging and underexplored area. In this study, we propose a DL-assisted method for the inverse design of transmissive metasurfaces. The method consists of a generative adversarial network (GAN)-based graph generator, an electromagnetic response predictor, and a genetic algorithm optimizer. By integrating these components, we can obtain customized metasurfaces with desired transmission characteristics of frequency band. We demonstrate the effectiveness of the proposed method through examples of inverse-designed three-layer cascaded transmissive metasurfaces with wideband, dual-band, and stopband responses in the 8∼12 GHz frequency range. Specifically, we realize three different types of dual-band metasurfaces, namely double-wide, front-wide and rear-narrow, and front-narrow and rear-wide configurations. Additionally, we analyze the accuracy and reliability of the inverse design method by employing data from the training dataset, self-defined objectives, and bandwidth-reduced target responses scaled from the wideband type as design inputs. Quantitative evaluation is performed using metrics such as mean absolute error and average precision. The proposed method successfully achieves the desired effect as intended.
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19
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Ma Z, Hong J, Lin S, Wan G, Long R, Wen J, Zhou X, Chen Y. Ultrawide and unidirectional enhancements of a photonic spin Hall effect in a tilted uniaxial crystal. OPTICS LETTERS 2023; 48:5811-5814. [PMID: 37910765 DOI: 10.1364/ol.504095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 10/15/2023] [Indexed: 11/03/2023]
Abstract
Since the enhancement of the photonic spin Hall effect (PSHE) is limited around the Brewster's angle, the scientific problem of how to extend the range of incident angles and to keep them unidirectional for the enhanced PSHE remains open. Here, we propose an effective method to achieve the ultrawide angle and unidirectional enhancement of PSHE via the omnidirectional Brewster's effect in a tilted uniaxial crystal. By properly setting the permittivity and the optical axial angle of the uniaxial crystal, the omnidirectional Brewster's effect can be obtained to realize an ultrawide angle enhancement of the PSHE. Then, by appropriately deviating the optical axial angle, the ultrawide enhancement of the PSHE can be achieved within the maximum incident angle range of 60° with unchanged direction. These findings inspire an unprecedented route to facilitate the applications in precision measurement and spin-dependent devices.
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20
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Huang Y, Liu B, Liu C, Hu X, Wu Y, Chew KH, Chen RP. Manipulation of polarization conversion and dual foci in a twisted caustic vector optical field in free space. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2023; 40:2052-2058. [PMID: 38038071 DOI: 10.1364/josaa.504384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 10/09/2023] [Indexed: 12/02/2023]
Abstract
Manipulation of polarization states in a complex structured optical field during propagation has become an important topic due to its fundamental interest and potential applications. This work demonstrates the effect of the caustic and twisting phases on the polarization states of a vector beam experimentally and theoretically. The novel properties of polarization evolution, especially the conversions of different states of polarization (SoPs) in a twisted caustic vector beam, occur during propagation in free space because of the modulation of twisting and caustic phases. The orthogonal polarization components tend to appear on the beam centers of two foci, and the two focal distances are closely related to the caustic and twisting phases. The twisting and caustic phases can manipulate the conversions between linear and circular polarization components that occur during propagation. These results provide a new approach to more complex manipulations of a structured optical field, especially in tailoring the evolution of polarization states and two foci. They may find potential applications in the corresponding field.
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21
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Zhao T, Lv X, Wang Y, Wu Y. Design of a Metasurface with Long Depth of Focus Using Superoscillation. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2500. [PMID: 37764531 PMCID: PMC10537551 DOI: 10.3390/nano13182500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 08/31/2023] [Accepted: 09/01/2023] [Indexed: 09/29/2023]
Abstract
Longitudinal optical field modulation is very important for applications such as optical imaging, spectroscopy, and optical manipulation. It can achieve high-resolution imaging or manipulation of the target object, but it is also limited by its depth of focus. The depth of focus determines whether the target object can be clearly imaged or manipulated at different distances, so extending the depth of focus can improve the adaptability and flexibility of the system. However, how to extend the depth of focus is still a significant challenge. In this paper, we use a super-oscillation phase modulation optimization method to design a polarization-independent metalens with extended focal depth, taking the axial focal depth length as the optimization objective. The optimized metalens has a focal depth of 13.07 μm (about 22.3 λ), and in the whole focal depth range, the transverse full width at half maximum values are close to the Rayleigh diffraction limit, and the focusing efficiency is above 10%. The results of this paper provide a new idea for the design of a metalens with a long focal depth and may have application value in imaging, lithography, and detection.
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Affiliation(s)
- Tianyu Zhao
- Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences, Changchun 130033, China
| | - Xiao Lv
- Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences, Changchun 130033, China
| | - Yue Wang
- Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences, Changchun 130033, China
| | - Yihui Wu
- Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences, Changchun 130033, China
- GD Changguang Zhongke Bio Co., Ltd., Foshan 528200, China
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22
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Xu Y, Wang Y, Zhou Q, Gao L, Fu Y. Unidirectional manipulation of Smith-Purcell radiation by phase-gradient metasurfaces. OPTICS LETTERS 2023; 48:4133-4136. [PMID: 37527136 DOI: 10.1364/ol.495263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 07/10/2023] [Indexed: 08/03/2023]
Abstract
Here, we present a new, to the best of our knowledge, approach to control Smith-Purcell radiation (SPR) via phase-gradient metasurfaces (PGMs), i.e., periodic grating structures with gradient phase modulation. We show that the phase gradient and the parity design of the PGM can efficiently manipulate higher order diffraction to achieve perfect unidirectional SPR, which significantly alters the SPR in the spectrum and the spatial distribution beyond traditional understanding. Specifically, the even-parity PGM results in incidence-free unidirectional radiation, while the odd-parity PGM enables incidence-locking unidirectional radiation. This unidirectional SPR is very robust, ensured by the parity-dependent diffraction rule in PGMs. A modified formula is presented to reveal the relationship between the radiation wavelength and the radiation angle. Our findings offer a new way to control the electromagnetic radiation of moving charged particles (CPs) with structured materials, which may lead to novel applications in tunable, efficient light sources and particle detectors.
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23
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Yang W, Ang LK, Zhang W, Han J, Xu Y. High sensitivity gas sensor based on surface exciton polariton enhanced photonic spin Hall effect. OPTICS EXPRESS 2023; 31:27041-27053. [PMID: 37710551 DOI: 10.1364/oe.497262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 07/17/2023] [Indexed: 09/16/2023]
Abstract
In this paper, the sub-wavelength transverse displacement of photonic spin Hall effect (PSHE) is significantly enhanced by the surface exciton polariton (SEP) for application in gas sensing. The transverse displacement of 14.4 times the wavelength of incident light is achieved with the SEP enhanced PSHE, which is about 3 times that of surface plasmon resonance enhanced PSHE. A gas sensor based on SEP enhanced PSHE is proposed for the detection of SO2, and the refractive index sensitivity of 6320.4 µm/RIU is obtained in the refractive index range from 1.00027281 to 1.00095981. These results undoubtedly demonstrate SEP to be a promising mechanism for PSHE enhancement, and open up new opportunities for highly sensitive gas sensing, biosensing, and chemical sensing.
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24
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Song H, Hong B, Wang N, Ping Wang G. Kerker-type positional disorder immune metasurfaces. OPTICS EXPRESS 2023; 31:24243-24259. [PMID: 37475256 DOI: 10.1364/oe.492419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 06/24/2023] [Indexed: 07/22/2023]
Abstract
Metasurfaces that can operate without a strictly periodic arrangement of meta-atoms are highly desirable for practical optical micro-nano devices. In this paper, we propose two kinds of Kerker-type metasurfaces that exhibit immunity to positional disorder. These metasurfaces consist of two distinct core-shell cylinders that satisfy the first and second Kerker conditions, respectively. Despite significant positional disorder perturbations of the meta-atoms, the metasurfaces can maintain excellent performance comparable to periodic ones, including total transmission and magnetic mirror responses. This positional disorder immunity arises from the unidirectional forward or backward scattering of a single core-shell cylinder, which results in minimal lateral scattering coupling between neighboring cylinders, thereby having little impact on multiple scattering in either the forward or backward direction. In contrast, the response of positional disorder non-Kerker-type metasurfaces decreases significantly. Our findings present a new approach for designing robust metasurfaces and expanding the applications of metasurfaces in sensing and communications within complex practical scenarios.
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25
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Wang M, Lin Y, Wang M, Yi JM, Gao X, Li DY, Liu JP, Cao B, Wang CH, Wang JF, Xu K. Double-sided asymmetric metasurfaces achieving sub-microscale focusing from a GaN green laser diode. OPTICS EXPRESS 2023; 31:20740-20749. [PMID: 37381190 DOI: 10.1364/oe.493257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 05/28/2023] [Indexed: 06/30/2023]
Abstract
We proposed and demonstrated a highly efficient sub-microscale focusing from a GaN green laser diode (LD) integrated with double-sided asymmetric metasurfaces. The metasurfaces consist of two nanostructures in a GaN substrate: nanogratings on one side and a geometric phase based metalens on the other side. When it was integrated on the edge emission facet of a GaN green LD, linearly polarized emission was firstly converted to the circularly polarized state by the nanogratings functioning as a quarter-wave plate, the phase gradient was then controlled by the metalens on the exit side. In the end, the double-sided asymmetric metasurfaces achieve a sub micro-focusing from linearly polarized states. Experimental results show the full width at half maximum of the focused spot size is about 738 nm at the wavelength 520 nm and the focusing efficiency is about 72.8%. Our results lay a foundation for the multi-functional applications in optical tweezers, laser direct writing, visible light communication, and biological chip.
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26
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Zhao P, Ding X, Li C, Tang S. Achieving Photonic Spin Hall Effect, Spin-Selective Absorption, and Beam Deflection with a Vanadium Dioxide Metasurface. MATERIALS (BASEL, SWITZERLAND) 2023; 16:4259. [PMID: 37374442 DOI: 10.3390/ma16124259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 06/01/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023]
Abstract
Metasurface-based research with phase-change materials has been a prominent and rapidly developing research field that has drawn considerable attention in recent years. In this paper, we proposed a kind of tunable metasurface based on the simplest metal-insulator-metal structure, which can be realized by the mutual transformation of insulating and metallic states of vanadium dioxide (VO2) and can realize the functional switching of photonic spin Hall effect (PSHE), absorption and beam deflection at the same terahertz frequency. When VO2 is insulating, combined with the geometric phase, the metasurface can realize PSHE. A normal incident linear polarized wave will be split into two spin-polarized reflection beams traveling in two off-normal directions. When VO2 is in the metal state, the designed metasurface can be used as a wave absorber and a deflector, which will completely absorb LCP waves, while the reflected amplitude of RCP waves is 0.828 and deflects. Our design only consists of one layer of artificial structure with two materials and is easy to realize in the experiment compared with the metasurface of a multi-layer structure, which can provide new ideas for the research of tunable multifunctional metasurface.
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Affiliation(s)
- Pengfei Zhao
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
| | - Xinyi Ding
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
| | - Chuang Li
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
| | - Shiwei Tang
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
- State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai 200433, China
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27
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Ma Z, Lai Z, Lin S, Hong J, Chen Y, Zhou X. Generalized Brewster angle-enhanced photonic spin Hall effect in an all-dielectric metasurface. OPTICS LETTERS 2023; 48:3003-3006. [PMID: 37262266 DOI: 10.1364/ol.488359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 04/27/2023] [Indexed: 06/03/2023]
Abstract
The enhancement of the photonic spin Hall effect (PSHE) is usually limited at horizontally polarized incidence and around the nonadjustable Brewster angle. In this Letter, a flexible method for enhancing the reflective PSHE with tunable incident angle under both vertically (V) and horizontally (H) polarized light has been theoretically explored. By using the multipole decomposition method, the variable generalized Brewster angle (GBA) is proven to be obtained under both V- and H-polarized light at different wavelengths in the all-dielectric metasurface. Then, owing to the large ratio of Fresnel coefficients at the GBA, the enhancement of PSHE in this Letter can not only be available for both V- and H-polarization, but also achieved at widely tunable incident angle and different operating wavelengths in the same metasurface. This work provides a simple method to achieve the flexible enhancement of PSHE and offers a novel way for designing a functional spin-based photonic device.
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28
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Lu J, Ginis V, Qiu CW, Capasso F. Polarization-Dependent Forces and Torques at Resonance in a Microfiber-Microcavity System. PHYSICAL REVIEW LETTERS 2023; 130:183601. [PMID: 37204895 DOI: 10.1103/physrevlett.130.183601] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 03/20/2023] [Indexed: 05/21/2023]
Abstract
Spin-orbit interactions in evanescent fields have recently attracted significant interest. In particular, the transfer of the Belinfante spin momentum perpendicular to the propagation direction generates polarization-dependent lateral forces on particles. However, it is still elusive as to how the polarization-dependent resonances of large particles synergize with the incident light's helicity and resultant lateral forces. Here, we investigate these polarization-dependent phenomena in a microfiber-microcavity system where whispering-gallery-mode resonances exist. This system allows for an intuitive understanding and unification of the polarization-dependent forces. Contrary to previous studies, the induced lateral forces at resonance are not proportional to the helicity of incident light. Instead, polarization-dependent coupling phases and resonance phases generate extra helicity contributions. We propose a generalized law for optical lateral forces and find the existence of optical lateral forces even when the helicity of incident light is zero. Our work provides new insights into these polarization-dependent phenomena and an opportunity to engineer polarization-controlled resonant optomechanical systems.
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Affiliation(s)
- Jinsheng Lu
- Harvard John A. Paulson School of Engineering and Applied Sciences, 9 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - Vincent Ginis
- Harvard John A. Paulson School of Engineering and Applied Sciences, 9 Oxford Street, Cambridge, Massachusetts 02138, USA
- Data Lab and Applied Physics, Vrije Universiteit Brussel, 1050 Brussel, Belgium
| | - Cheng-Wei Qiu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore
| | - Federico Capasso
- Harvard John A. Paulson School of Engineering and Applied Sciences, 9 Oxford Street, Cambridge, Massachusetts 02138, USA
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29
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Liu H, Yuan L. Controlling the spin Hall effect of grafted vortex beams propagating in uniaxial crystal. OPTICS EXPRESS 2023; 31:10434-10448. [PMID: 37157590 DOI: 10.1364/oe.485247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Though numerous studies of spin-orbit interaction (SOI) of light beams propagating along the optic axis of uniaxial crystals have been carried out, in previous studies, the initial input beams have cylindrical symmetry. In this case, the total system preserves cylindrical symmetry so that the output light after passing through the uniaxial crystal doesn't exhibit spin dependent symmetry breaking. Therefore, no spin Hall effect (SHE) occurs. In this paper, we investigate the SOI of a kind of novel structured light beam, grafted vortex beam (GVB) in uniaxial crystal. The cylindrical symmetry of the system is broken by the spatial phase structure of the GVB. As a result, a SHE determined by the spatial phase structure emerges. It is found that the SHE and evolution of the local angular momentum are controllable both by changing the grafted topological charge of the GVB and by employing linear electro-optic effect of the uniaxial crystal. This can open a new perspective to investigate the SHE of light beams in uniaxial crystals via constructing and manipulating the spatial structure of the input beams artificially, hence offers novel regulation capabilities of spin photon.
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30
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Yang LP. Geometric phase for twisted light. OPTICS EXPRESS 2023; 31:10287-10296. [PMID: 37157579 DOI: 10.1364/oe.476989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Polarization vectors of light traveling in a coiled optical fiber rotate around its propagating axis even in the absence of birefringence. This rotation was usually explained due to the Pancharatnam-Berry phase of spin-1 photons. Here, we use a purely geometric method to understand this rotation. We show that similar geometric rotations also exist for twisted light carrying orbital angular momentum (OAM). The corresponding geometric phase can be applied in photonic OAM-state-based quantum computation and quantum sensing.
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31
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Shu Y, Song Y, Wen Z, Zhang Y, Liu S, Liu J, Luo Z. Theory of quantized photonic spin Hall effect in strained graphene under a sub-Tesla external magnetic field. OPTICS EXPRESS 2023; 31:8805-8819. [PMID: 36859988 DOI: 10.1364/oe.483506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 02/12/2023] [Indexed: 06/18/2023]
Abstract
The quantized photonic spin Hall effect (PSHE) in the strained graphene-substrate system is predicted under a sub-Tesla external magnetic field, which is two orders of magnitude smaller than required to produce the quantized effect in the conventional graphene-substrate system. It is found that in-plane and transverse spin-dependent splittings in the PSHE, exhibit different quantized behaviors and are closely related to the reflection coefficients. Unlike the quantized PSHE in the conventional graphene-substrate system formed by the splitting of real Landau levels, the quantized PSHE in the strained graphene-substrate system is attributed to the splitting of pseudo-Landau levels caused by the pseudo-magnetic field and the lifting of valley degeneracy of the n ≠ 0 pseudo-Landau levels induced by the sub-Tesla external magnetic field. At the same time, the pseudo-Brewster angles of the system are also quantized with the change of Fermi energy. The sub-Tesla external magnetic field and the PSHE appear as quantized peak values near these angles. The giant quantized PSHE is expected to be used for direct optical measurements of the quantized conductivities and pseudo-Landau levels in the monolayer strained graphene.
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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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Wang X, Sentz T, Bharadwaj S, Ray SK, Wang Y, Jiao D, Qi L, Jacob Z. Observation of nonvanishing optical helicity in thermal radiation from symmetry-broken metasurfaces. SCIENCE ADVANCES 2023; 9:eade4203. [PMID: 36706175 PMCID: PMC9882974 DOI: 10.1126/sciadv.ade4203] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 12/28/2022] [Indexed: 06/18/2023]
Abstract
Spinning thermal radiation is a unique phenomenon observed in condensed astronomical objects, including the Wolf-Rayet star EZ-CMa and the red degenerate star G99-47, due to the existence of strong magnetic fields. Here, by designing symmetry-broken metasurfaces, we demonstrate that spinning thermal radiation with a nonvanishing optical helicity can be realized even without applying a magnetic field. We design nonvanishing optical helicity by engineering a dispersionless band that emits omnidirectional spinning thermal radiation, where our design reaches 39% of the fundamental limit. Our results firmly suggest that metasurfaces can impart spin coherence in the incoherent radiation excited by thermal fluctuations. The symmetry-based design strategy also provides a general pathway for controlling thermal radiation in its temporal and spin coherence.
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Affiliation(s)
- Xueji Wang
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Tyler Sentz
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Sathwik Bharadwaj
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Subir Kumar Ray
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Yifan Wang
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Dan Jiao
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Limei Qi
- School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China
| | - Zubin Jacob
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA
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34
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Qin Z, Zhang L, Zhang R, Zhang P, Qi R, Zhang Q, Ren L, Jiang L. Effect of the incident polarization on in-plane and out-of-plane spin splitting near the critical angle. OPTICS EXPRESS 2023; 31:853-863. [PMID: 36785133 DOI: 10.1364/oe.475740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 11/13/2022] [Indexed: 06/18/2023]
Abstract
To reveal the effect of the incident polarization on the spin splitting of the photonic spin Hall effect (that is, the spatial and angular in-plane and out-of-plane spin splitting), we systematically study the phenomena and characteristics of these four spin splitting generated when the beam with arbitrary linear polarization is reflected from the non-absorbing medium interface and the absorbing medium interface. Several features of the relationship between the incident polarization and the four kinds of spin splitting are found. In addition, It is also found that the in-plane angular and spatial shifts are significantly enhanced near the critical angle, even reaching their theoretical upper limit. However, the out-of-plane shifts are not enhanced. The research in this paper will contribute to a deeper understanding of PSHE. These findings can also provide new ideas and methods for precision metrology, photonic manipulation, and photonic device fabrication.
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Li Z, Zhang Y, Yuan J, Hong Y, Liu H, Guo J, Dai Q, Wei Z. Three-Channel Metasurfaces for Multi-Wavelength Holography and Nanoprinting. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 13:183. [PMID: 36616093 PMCID: PMC9824896 DOI: 10.3390/nano13010183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 12/27/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
Metasurfaces, employed to simultaneously generate nanoprinting and holographic images, have been extensively explored recently. Among them, multi-wavelength multiplexing in a single metasurface is often accompanied by dispersion and crosstalk, which hinder the display of multicolor patterns. Here, we propose an efficient phase method to decouple the wavelength and realize a three-channel display operating at different wavelengths. Holographic images appear in the far field with the illumination of two different circularly polarized lights while a nanoprinting image is reconstructed by inserting an orthogonal optical path with the illumination of linear polarization light. The proposed metasurface is only composed of four types of unit cells, which significantly decreases the complexity of fabrication and improves the information capacity. Benefiting from its different decoding strategies and capability of multi-wavelength control, this approach may develop broad applications in information encryption, security, and color display.
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36
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Kim M, Lee D. Strengthened Spin Hall Effect of Circularly Polarized Light Enabled by a Single-Layered Dielectric Metasurface. MATERIALS (BASEL, SWITZERLAND) 2022; 16:283. [PMID: 36614622 PMCID: PMC9821799 DOI: 10.3390/ma16010283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 12/20/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
The spin Hall effect of light, referring to the spin-dependent and transverse splitting of light at an optical interface, is an interface-dependent phenomenon. In contrast to this commonly accepted statement, it has been recently reported that the spin Hall effect under circularly polarized light is interface-independent. Despite this interface-independence, however, the reflection of the spin Hall shifted beam is mostly suppressed under near-normal incidence, where the spin Hall shift is large because of the handedness reversal that occurs during the reflection. Here we present a single-layered dielectric metasurface to realize the interface-independent and strengthened spin Hall effect of light. Numerical simulation results confirmed that the anisotropic geometry of the metasurface induced phase-reversed reflection for one linear polarization and phase-preserved reflection for the other, thereby strongly strengthening the reflection of the spin-Hall-shifted beam. Our work will pave a route toward the precise displacement of the beam at the nanoscale without perturbing its polarization state.
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Affiliation(s)
- Minkyung Kim
- School of Mechanical Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Dasol Lee
- Department of Biomedical Engineering, Yonsei University, Wonju 26493, Republic of Korea
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37
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Da H, Song Q, Hu P, Ye H. Enhanced photonic spin Hall effect in Dirac semimetal metamaterial enabled by zero effective permittivity. NANOTECHNOLOGY 2022; 34:105201. [PMID: 36537746 DOI: 10.1088/1361-6528/aca80e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
With the recent discovery of three dimensional Dirac semimetals, their integrations with the optoelectronic devices allow the novel optical effects and functionalities. Here, we theoretically report the photonic spin Hall effect in a periodic structure, where three dimensional Dirac semimetals and the dielectric materials are assembled into the stack. The incident angle and frequency dependent spin shift spectrum reveals that the spin shifts of the transmitted wave in this structure emerge the obvious peaks and valleys for the horizontal polarized wave and their magnitudes and positions display a distinct dependence on the incident angle around the specific frequency. These observations originate from its zero value of the effective perpendicular permittivity and its greatly reduced transmission in the multilayered structure, whose mechanism is different from those in the previous works. Moreover, both the peaks and valleys of the transmitted spin shift are significantly sensitive to the Fermi energy of three dimensional Dirac semimetals, whose magnitudes and positions can be tuned by varying it. Our results highlight the vital role of three dimensional Dirac semimetals in their applications of the spin photonic devices and pave the way to explore the tunable photonic spin Hall effect by engineering their Fermi energies.
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Affiliation(s)
- Haixia Da
- College of Electronic and Optical Engineering & College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing, Jiangsu, 210046, China; Key Laboratory of Radio Frequency and Micro-Nano Electronics of Jiangsu Province, Nanjing 210023, People's Republic of China
| | - Qi Song
- College of Electronic and Optical Engineering & College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing, Jiangsu, 210046, China; Key Laboratory of Radio Frequency and Micro-Nano Electronics of Jiangsu Province, Nanjing 210023, People's Republic of China
| | - Pengya Hu
- College of Electronic and Optical Engineering & College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing, Jiangsu, 210046, China; Key Laboratory of Radio Frequency and Micro-Nano Electronics of Jiangsu Province, Nanjing 210023, People's Republic of China
| | - Huapeng Ye
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China, National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, People's Republic of China
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Wang J, Shi L, Zi J. Spin Hall Effect of Light via Momentum-Space Topological Vortices around Bound States in the Continuum. PHYSICAL REVIEW LETTERS 2022; 129:236101. [PMID: 36563232 DOI: 10.1103/physrevlett.129.236101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 11/02/2022] [Indexed: 06/17/2023]
Abstract
Optical bound states in the continuum (BICs) are exotic topological defects in photonic crystal slabs, carrying polarization topological vortices in momentum space. The topological vortex configurations not only topologically protect the infinite radiation lifetime of BICs, but also intrinsically contain many unexploited degrees of freedom for light manipulation originating from BICs. Here, we theoretically propose and experimentally demonstrate the spin Hall effect of light in photonic crystal slabs via momentum-space topological vortices around BICs. The strong spin-orbit interactions of light are induced by using the topological vortices around BICs, introducing both wave-vector-dependent Pancharatnam-Berry phase gradients and cross-polarized resonant phase gradients to the spinning light beam, which lead to spin-dependent in-plane-oblique lateral light beam shifts. Our work reveals intriguing spin-related topological effects around BICs, opening an avenue toward applications of BICs in integrated spin-optical devices and information processing.
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Affiliation(s)
- Jiajun Wang
- State Key Laboratory of Surface Physics, Key Laboratory of Micro- and Nano-Photonic Structures (Ministry of Education) and Department of Physics, Fudan University, Shanghai 200433, China
| | - Lei Shi
- State Key Laboratory of Surface Physics, Key Laboratory of Micro- and Nano-Photonic Structures (Ministry of Education) and Department of Physics, Fudan University, Shanghai 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200438, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Jian Zi
- State Key Laboratory of Surface Physics, Key Laboratory of Micro- and Nano-Photonic Structures (Ministry of Education) and Department of Physics, Fudan University, Shanghai 200433, China
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200438, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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Ni J, Liu S, Chen Y, Hu G, Hu Y, Chen W, Li J, Chu J, Qiu CW, Wu D. Direct Observation of Spin-Orbit Interaction of Light via Chiroptical Responses. NANO LETTERS 2022; 22:9013-9019. [PMID: 36326581 DOI: 10.1021/acs.nanolett.2c03266] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The spin-orbit interaction of light is a fundamental manifestation of controlling its angular momenta with numerous applications in photonic spin Hall effects and chiral quantum optics. However, observation of an optical spin Hall effect, which is normally very weak with subwavelength displacements, needs quantum weak measurements or sophisticated metasurfaces. Here, we theoretically and experimentally demonstrate the spin-orbit interaction of light in the form of strong chiroptical responses by breaking the in-plane inversion symmetry of a dielectric substrate. The chiroptical signal is observed at the boundary of a microdisk illuminated by circularly polarized vortex beams at normal incidence. The generated chiroptical spectra are tunable for different photonic orbital angular momenta and microdisk diameters. Our findings, correlating photonic spin-orbit interaction with chiroptical responses, may provide a route for exploiting optical information processing, enantioselective sensing, and chiral metrology.
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Affiliation(s)
- Jincheng Ni
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore117583, Singapore
| | - Shunli Liu
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui230027, People's Republic of China
| | - Yang Chen
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui230027, People's Republic of China
| | - Guangwei Hu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore117583, Singapore
| | - Yanlei Hu
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui230027, People's Republic of China
| | - Weijin Chen
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore117583, Singapore
| | - Jiawen Li
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui230027, People's Republic of China
| | - Jiaru Chu
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui230027, People's Republic of China
| | - Cheng-Wei Qiu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore117583, Singapore
| | - Dong Wu
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui230027, People's Republic of China
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40
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Zhi J, Hu B, Guo Y, Sun Z, Wang X, Qiu Z, Ying H, Xu B. Generation of non-diffractive Lommel beams based on all-dielectric metasurfaces. OPTICS EXPRESS 2022; 30:42214-42223. [PMID: 36366679 DOI: 10.1364/oe.474951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 10/23/2022] [Indexed: 06/16/2023]
Abstract
Lommel beam is a non-diffractive vortex beam of high concern recently, widely used in communication and turbulence studies. However, conventional methods of generating Lommel beams, such as using spatial light modulators (SLMs), are limited by their low resolution, poor phase manipulation, and small numerical aperture (NA). Here, non-diffractive Lommel beams based on all-dielectric metasurfaces are proposed. Using the Pancharatnam-Berry (PB) phase arrangement, the focal depth of the main lobe of the generated beam can reach 75 µm (∼119λ). Additionally, the broadband characteristics of the designed metasurface between 550 and 710 nm are observed. The resulting beam is demonstrated to show excellent self-healing properties by placing up obstacles. We also combine the phase of the Dammann grating with that of the Lommel beam to create a metasurface capable of producing a 1 × 4 Lommel beam array; the generated beams are still characterized by uniformity and non-diffraction. This study provides a new idea for Lommel beam generation with promising applications in optical communication, optical tweezers, and laser fabrication.
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41
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Jiang L, Kong KV, He S, Yong K. Plasmonic Biosensing with Nano‐Engineered Van der Waals Interfaces. Chempluschem 2022; 87:e202200221. [DOI: 10.1002/cplu.202200221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 09/27/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Li Jiang
- School of Electrical and Electronic Engineering Nanyang Technological University 639798 Singapore Singapore
- State Key Laboratory of Modern Optical Instrumentation Centre for Optical and Electromagnetics Research JORCEP (Sino-Swedish Joint Research Center of Photonics) Zhejiang University Hangzhou 310058 P. R. China
- CINTRA CNRS/NTU/THALES, UMI 3288 Research Techno Plaza 50 Nanyang Drive Border X Block 637553 Singapore Singapore
| | - Kien Voon Kong
- Department of Chemistry National Taiwan University Taipei City Taiwan 10617
| | - Sailing He
- State Key Laboratory of Modern Optical Instrumentation Centre for Optical and Electromagnetics Research JORCEP (Sino-Swedish Joint Research Center of Photonics) Zhejiang University Hangzhou 310058 P. R. China
| | - Ken‐Tye Yong
- School of Biomedical Engineering The University of Sydney Sydney New South Wales 2006 Australia
- The University of Sydney Nano Institute The University of Sydney Sydney New South Wales 2006 Australia
- The Biophotonics and MechanoBioengineering Lab The University of Sydney Sydney New South Wales 2006 Australia
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42
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Cheng M, Fu P, Chen S. Giant photonic spin Hall effect in bilayer borophene metasurfaces. OPTICS EXPRESS 2022; 30:40075-40086. [PMID: 36298946 DOI: 10.1364/oe.473351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
We investigate theoretically the photonic spin Hall effect (PSHE) in bilayer borophene metasurfaces. Based on the combined effect of the Fabry-Perot resonance of the bilayer system and the resonant interaction of individual meta-atoms in borophene metasurface which lead to the topological transition, it is found that there exist giant PSHE shifts of the transmitted beams which can be flexibly regulated by adjusting the twist angle of metasurface bilayers, incident angle, spacer refractive index and spacer thickness. Near the topological transition of borophene metasurface the magnitude of PHSE shifts in bilayer borophene metasurfaces is generally on the order of tens of wavelengths and even on the order of hundreds of wavelengths near the epsilon-near-zero (ENZ) regions. The manipulation frequency range of the large PSHE shifts can reach hundreds of terahertz or even picohertz through adjusting the ribbon width of borophene metasurface or the electron density for borophene. It is found that in bilayer borophene metasurfaces there exist the ultrahigh sensitivity of the PSHE shifts to spacer refractive index, which can be applied to design the refractive index sensors with high performance.
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43
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Sheng L, Zhou X, Chen Y, Zhang H, Zhang Z. Role of in-plane shift in reconstructing the photonic spin Hall effect. OPTICS LETTERS 2022; 47:4778-4781. [PMID: 36107088 DOI: 10.1364/ol.472711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
The photonic spin Hall effect (SHE) manifests itself as in-plane and transverse spin-dependent shifts of left- and right-handed circularly polarized (LCP, RCP) components and originates from the spin-orbit interaction (SOI) of light, where extrinsic orbital angular momentum (EOAM) can induce these shifts. However, previous studies mainly focus on the SOI corresponding to transverse shifts and generally consider the paraxial approximation case. In this Letter, we reconstruct a more general theory of the photonic SHE in the non-paraxial case and reveal that the induction of an in-plane shift mainly relies on the EOAM of the y direction, supplemented by the EOAM of the x and z directions under the laboratory coordinate system. In addition, the EOAM in the x and z directions completely determine the transverse shift. Moreover, the angular momentum conversion between the LCP and RCP components results in the angular momentum of the LCP (RCP) component of the incident Gaussian beam not being equal to the sum of the angular momentum of the LCP (RCP) component of the reflected and transmitted light. These findings explore the influence of in-plane shifts on the SOI of light and provide an in-depth understanding of the photonic SHE.
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44
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Wu Q, Fan W, Qin C. Generation and Superposition of Perfect Vortex Beams in Terahertz Region via Single-Layer All-Dielectric Metasurface. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:3010. [PMID: 36080049 PMCID: PMC9457957 DOI: 10.3390/nano12173010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 08/25/2022] [Accepted: 08/26/2022] [Indexed: 06/15/2023]
Abstract
Terahertz (THz) orbital angular momentum (OAM) technology provides promising applications in future wireless communication with large bandwidth and high capacity. However, the ring radius of the conventional THz vortex beam is related to the topological charge, limiting the co-propagation of multiple OAM modes in the THz communication systems. Although the perfect vortex beam (PVB) based on traditional methods can solve this problem, they are usually bulky and unstable. Here, we demonstrate two PVB generators based on a single all-dielectric metasurface to obtain polarization-independent PVB and spin multiplexed PVB, respectively. The former regulates the propagation phase by using isotropic unit cells; the latter simultaneously manipulates the propagation and geometric phase to achieve the spin-decoupled phase control by arranging anisotropic unit cells. In addition, we also demonstrate the stable generation of a perfect Poincaré beam with arbitrary polarization and phase distribution on a hybrid-order Poincaré Sphere via a spin-decoupled metasurface, which is achieved by the linear superposition of two PVBs with orthogonal circular polarizations. The proposed scheme provides a compact and efficient platform for the generation and superposition of PVBs in THz region, and will speed up the progress of THz communication systems, complex light field generation, and quantum information sciences.
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Affiliation(s)
- Qi Wu
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
- School of Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenhui Fan
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
- School of Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
| | - Chong Qin
- State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
- School of Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
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45
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Salehi M, Rahmatian P, Memarian M, Mehrany K. Frequency conversion in time-varying graphene microribbon arrays. OPTICS EXPRESS 2022; 30:32061-32073. [PMID: 36242275 DOI: 10.1364/oe.467479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 08/06/2022] [Indexed: 06/16/2023]
Abstract
We investigate the possibility of frequency conversion in time-varying metasurfaces, composed of graphene microribbon arrays (GMRAs) with time-periodic modulation of their conductivity. We present a quasi-static model for the interaction of light with a temporally modulated metasurface, as well as an accurate analytical treatment of the problem of time-varying GMRAs. Results coming from numerical simulations are also available. We provide corrections to a previous related proposal for frequency conversion and refute the possibility of attaining frequency shifts not equal to an integral multiple of modulation frequency. Contrary to the preceding results, our findings show that efficient frequency conversion demands more requisites than single-layer GMRAs can supply and that its requirements can be addressed successfully by a multi-layer design.
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46
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Peng L, Ren H, Liu YC, Lan TW, Xu KW, Ye DX, Sun HB, Xu S, Chen HS, Zhang S. Spin Hall effect of transversely spinning light. SCIENCE ADVANCES 2022; 8:eabo6033. [PMID: 36026456 PMCID: PMC9417169 DOI: 10.1126/sciadv.abo6033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
Light carries spin angular momentum, which, in the free space, is aligned to the direction of propagation and leads to intriguing spin Hall phenomena at an interface. Recently, it was shown that a transverse-spin (T-spin) state could exist for surface waves at an interface or for bulk waves inside a judiciously engineered metamaterial, with the spin oriented perpendicular to the propagation direction. Here, we demonstrate the spin Hall effect for transversely spinning light-a T-spin-induced beam shift at the interface of a metamaterial. It is found that the beam shift takes place in the plane of incidence, in contrast to the well-known Imbert-Fedorov shifts. The observed T-spin-induced beam shift is of geometrodynamical nature, which can be rendered positive or negative controlled by the orientation of T-spin of the photons. The unconventional spin Hall effect of light found here provides a previously unexplored mechanism for manipulating light-matter interactions at interfaces.
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Affiliation(s)
- Liang Peng
- School of Information and Electrical Engineering, Zhejiang University City College, Hangzhou, China
- School of electronics and information, Hangzhou Dianzi University, Hangzhou, China
| | - Hang Ren
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, China
| | - Ya-Chao Liu
- Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, China
| | - Tian-Wei Lan
- School of electronics and information, Hangzhou Dianzi University, Hangzhou, China
| | - Kui-Wen Xu
- School of electronics and information, Hangzhou Dianzi University, Hangzhou, China
| | - De-Xin Ye
- Laboratory of Applied Research on Electromagnetics (ARE), Zhejiang University, Hangzhou, China
| | - Hong-Bo Sun
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, China
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, China
| | - Su Xu
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, China
| | - Hong-Sheng Chen
- State Key Laboratory of Modern Optical Instrumentation, Interdisciplinary Center for Quantum Information, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, China
| | - Shuang Zhang
- Department of Physics, University of Hong Kong, Hong Kong, China
- Department of Electrical and Electronic Engineering, University of Hong Kong, Hong Kong, China
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47
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Yue Z, Xu J, Lu P, Teng S. Versatile Integrated Polarizers Based on Geometric Metasurfaces. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:2816. [PMID: 36014681 PMCID: PMC9416469 DOI: 10.3390/nano12162816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/08/2022] [Accepted: 08/10/2022] [Indexed: 06/15/2023]
Abstract
We propose versatile integrated polarizers based on geometric metasurfaces. Metasurface polarizer consists of an L-shaped hole array etched on a silver film, and it can simultaneously generate several polarization states, including linear polarization, circular polarization, elliptical polarization, or even hybrid polarization. Meanwhile, the combination of output polarization states changes with the illumination polarization type. The theoretical analysis provides a detailed explanation for the generation of the integrated polarization states. The well-designed metasurface polarizers may generate more complex polarization modes, including vector beams and vector vortex beams. The theoretical and simulated results confirm the polarization performance of the proposed integrated metasurface polarizers. The compact design of metasurface polarizers and the controllable generation of versatile polarization combinations are a benefit to the applications of polarization light in optical imaging, biomedical sensing, and material processing.
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Jen YJ, Lin PC, Lo XH. Silver split nano-tube array as a meta-atomic monolayer for high-reflection band. Sci Rep 2022; 12:13611. [PMID: 35948572 PMCID: PMC9365859 DOI: 10.1038/s41598-022-17703-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 07/29/2022] [Indexed: 12/02/2022] Open
Abstract
In this work, an ultra-thin silver film-coated grating as a split silver nanotube array exhibits not only high TE polarized reflectance as a conventional subwavelength grating but also high TM polarized reflectance that is close to or higher than TE reflectance at certain wavelength range. The TM reflectance peak shifts with the morphology of the silver covering. The near-field analysis reveals that the silver nanotube array is an ultra-thin optical double negative metamaterial. The negative permeability associated magnetic field reversal is induced within the grating that is surrounded by a split current loop at the TM reflectance peak wavelength. The near field simulation is used to retrieve the equivalent electromagnetic parameters and optical constants that cause the anomalous TM high reflection. It is demonstrated that the TM impedances have a low magnitude and high magnitude with respect to unity for light incident onto the top and bottom of the grating at the peak wavelength, respectively.
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Affiliation(s)
- Yi-Jun Jen
- Department of Electro-Optical Engineering, National Taipei University of Technology, Taipei, 106, Taiwan.
| | - Po-Chun Lin
- Department of Electro-Optical Engineering, National Taipei University of Technology, Taipei, 106, Taiwan
| | - Xing-Hao Lo
- Department of Electro-Optical Engineering, National Taipei University of Technology, Taipei, 106, Taiwan
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Liu S, Qi S, Li Y, Wei B, Li P, Zhao J. Controllable oscillated spin Hall effect of Bessel beam realized by liquid crystal Pancharatnam-Berry phase elements. LIGHT, SCIENCE & APPLICATIONS 2022; 11:219. [PMID: 35821002 PMCID: PMC9276670 DOI: 10.1038/s41377-022-00888-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/31/2022] [Accepted: 06/10/2022] [Indexed: 06/01/2023]
Abstract
Pancharatnam-Berry (PB) phase has become an effective tool to realize the photonic spin Hall effect (PSHE) in recent years, due to its capacity of enhancing the spin-orbit interaction. Various forms of PSHEs have been proposed by tailoring the PB phase of light, however, the propagation trajectory control of the separated spin states has not been reported. In this paper, we realize the oscillated spin-dependent separation by using the well-designed PB phase optical elements based on the transverse-to-longitudinal mapping of Bessel beams. Two typical oscillated PSHEs, i.e., the spin states are circulated and reversed periodically, are experimentally demonstrated with two PB phase elements fabricated with liquid crystal. The displacements and periods of these oscillations can be controlled by changing the transverse vector of the input Bessel beam. The proposed method offers a new degree of freedom to manipulate the spin-dependent separation, and provides technical supports for the application in spin photonics.
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Affiliation(s)
- Sheng Liu
- Key Laboratory of Light Field Manipulation and Information Acquisition, Ministry of Industry and Information Technology, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an, 710129, China
| | - Shuxia Qi
- Key Laboratory of Light Field Manipulation and Information Acquisition, Ministry of Industry and Information Technology, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an, 710129, China
| | - Yanke Li
- Key Laboratory of Light Field Manipulation and Information Acquisition, Ministry of Industry and Information Technology, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an, 710129, China
| | - Bingyan Wei
- Key Laboratory of Light Field Manipulation and Information Acquisition, Ministry of Industry and Information Technology, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an, 710129, China.
| | - Peng Li
- Key Laboratory of Light Field Manipulation and Information Acquisition, Ministry of Industry and Information Technology, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an, 710129, China.
| | - Jianlin Zhao
- Key Laboratory of Light Field Manipulation and Information Acquisition, Ministry of Industry and Information Technology, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an, 710129, China.
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Wang HP, Zhou YX, Li H, Liu GD, Yin SM, Li PJ, Dong SY, Gong CY, Wang SY, Li YB, Cui TJ. Noncontact Electromagnetic Wireless Recognition for Prosthesis Based on Intelligent Metasurface. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2105056. [PMID: 35524585 PMCID: PMC9284131 DOI: 10.1002/advs.202105056] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 03/29/2022] [Indexed: 05/31/2023]
Abstract
With the development of artificial intelligence and Internet of Things, hand gesture recognition techniques have attracted great attention owing to their excellent applications in developing human-machine interaction (HMI). Here, the authors propose a non-contact hand gesture recognition method based on intelligent metasurface. Owing to the advantage of dynamically controlling the electromagnetic (EM) focusing in the wavefront engineering, a transmissive programmable metasurface is presented to illuminate the forearm with more focusing spots and obtain comprehensive echo data, which can be processed under the machine learning technology to reach the non-contact gesture recognition with high accuracy. Compared with the traditional passive antennas, unique variations of echo coefficients resulted from near fields perturbed by finger and wrist agonist muscles can be aquired through the programmable metasurface by switching the positions of EM focusing. The authors realize the gesture recognition using support vector machine algorithm based on five individual focusing spots data and all-five-spot data. The influences of the focusing spots on the gesture recognition are analyzed through linear discriminant analysis algorithm and Fisher score. Experimental verifications prove that the proposed metasurface-based non-contact wireless design can realize the classification of hand gesture recognition with higher accuracy than traditional passive antennas, and give an HMI solution.
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Affiliation(s)
- Hai Peng Wang
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
- Research Center of Applied ElectromagneticsNanjing University of Information Science and TechnologyNanjing210044China
| | - Yu Xuan Zhou
- Department of Biomedical EngineeringSchool of Biomedical Engineering and InformaticsNanjing Medical UniversityNanjing211166China
| | - He Li
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
| | - Guo Dong Liu
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
| | - Si Meng Yin
- Department of Biomedical EngineeringSchool of Biomedical Engineering and InformaticsNanjing Medical UniversityNanjing211166China
| | - Peng Ju Li
- Department of Biomedical EngineeringSchool of Biomedical Engineering and InformaticsNanjing Medical UniversityNanjing211166China
| | - Shu Yue Dong
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
| | - Chao Yue Gong
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
| | - Shi Yu Wang
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
| | - Yun Bo Li
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
| | - Tie Jun Cui
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
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