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Shahwar D, Kapulainen M, Haatainen T, Harjanne M, Cherchi M, Sun Z, Aalto T, Tappura K. On-Chip Polarization Rotators Using Metasurface. ACS OMEGA 2024; 9:33055-33063. [PMID: 39100281 PMCID: PMC11292811 DOI: 10.1021/acsomega.4c04158] [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: 04/30/2024] [Revised: 06/15/2024] [Accepted: 07/09/2024] [Indexed: 08/06/2024]
Abstract
Metasurfaces, with their ability to finely manipulate light properties (e.g., polarization), represent a frontier in optical technology. Here, we report innovative gold-based metasurfaces that are adept at changing the light polarization across a broad range of incident angles. Their expansive acceptance angle facilitates seamless integration with silicon waveguides, culminating in the realization of a novel, compact, broadband, and low-loss on-chip polarization rotator. The demonstrated metasurface devices show polarization conversion efficiencies as high as 98.5% at 1550 nm in the free space measurements. Unlike conventional plasmonic metasurfaces, which lack broadband capabilities, our metasurface-based waveplates show extinction ratios of >15 dB for a 120 nm bandwidth. These metasurfaces are positioned on top of up-reflecting mirrors fabricated in a micrometer-scale silicon-on-insulator platform to demonstrate on-chip polarization rotation. The demonstrated polarization rotator shows an extinction ratio of more than 10 dB for a 100 nm bandwidth. This study marks the first successful demonstration of on-chip polarization manipulation utilizing metasurface integration, heralding significant potential impacts for enhancing the functionality and miniaturization of photonic integrated circuits.
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Affiliation(s)
- Dura Shahwar
- VTT
Technical Research Centre of Finland Ltd, Tietotie 3, 02150 Espoo, Finland
- QTF
Centre of Excellence, Department of Electronics and Nanoengineering, Aalto University, 02150 Espoo, Finland
| | - Markku Kapulainen
- VTT
Technical Research Centre of Finland Ltd, Tietotie 3, 02150 Espoo, Finland
| | - Tomi Haatainen
- VTT
Technical Research Centre of Finland Ltd, Tietotie 3, 02150 Espoo, Finland
| | - Mikko Harjanne
- VTT
Technical Research Centre of Finland Ltd, Tietotie 3, 02150 Espoo, Finland
| | - Matteo Cherchi
- VTT
Technical Research Centre of Finland Ltd, Tietotie 3, 02150 Espoo, Finland
| | - Zhipei Sun
- QTF
Centre of Excellence, Department of Electronics and Nanoengineering, Aalto University, 02150 Espoo, Finland
| | - Timo Aalto
- VTT
Technical Research Centre of Finland Ltd, Tietotie 3, 02150 Espoo, Finland
| | - Kirsi Tappura
- VTT
Technical Research Centre of Finland Ltd, Tietotie 3, 02150 Espoo, Finland
- QTF
Centre of Excellence, VTT Technical Research
Centre of Finland Ltd, FI-02044 VTT Espoo, Finland
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2
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Hou M, Chen Y, Li J, Yi F. Single 5-centimeter-aperture metalens enabled intelligent lightweight mid-infrared thermographic camera. SCIENCE ADVANCES 2024; 10:eado4847. [PMID: 38968354 PMCID: PMC11225786 DOI: 10.1126/sciadv.ado4847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 06/04/2024] [Indexed: 07/07/2024]
Abstract
Existing mid-infrared thermographic cameras rely on a stack of refractive lenses, resulting in bulky and heavy imaging systems that restrict their broader utility. Here, we demonstrate a lightweight metalens-based thermographic camera (MTC) enabled by a single 0.5-mm-thick, 3.7-g-weight, flat, and mass-producible metalens. The large aperture size (5 cm) of our metalens, when combined with an uncooled focal plane array, enables thermal imaging at distances of tens of meters. By computationally removing the veiling glare, our MTC realizes the temperature mapping with an inaccuracy of less than ±0.7% within the range of 35° to 700°C and shows exceptional environmental adaptability. Furthermore, by using intelligent algorithms and spectral filtering, our uncooled MTC enables visualization and quantification of the SF6 gas leakage at a long distance of 5 m, with a remarkable minimum detectable leak rate of 0.2 sccm. Our work opens the door to the lightweight and multifunctional intelligent thermal imaging systems.
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Affiliation(s)
- Mingming Hou
- School of Optical and Electronic Information and Wuhan National Research Center for Optoelectronics (WNLO), Huazhong University of Science and Technology, Hubei, Wuhan 430074, China
| | - Yan Chen
- School of Optical and Electronic Information and Wuhan National Research Center for Optoelectronics (WNLO), Huazhong University of Science and Technology, Hubei, Wuhan 430074, China
| | - Junyu Li
- IRay Technology Co. Ltd., Yantai 264006, China
| | - Fei Yi
- School of Optical and Electronic Information and Wuhan National Research Center for Optoelectronics (WNLO), Huazhong University of Science and Technology, Hubei, Wuhan 430074, China
- Optics Valley Laboratory, Hubei 430074, China
- Shenzhen Huazhong University of Science and Technology Research Institute, Shenzhen 518000, China
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3
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Wu Y, Liu J, Yu W, Zhang T, Mu H, Si G, Cui Z, Lin S, Zheng B, Qiu CW, Chen H, Ou Q. Monolithically Structured van der Waals Materials for Volume-Polariton Refraction and Focusing. ACS NANO 2024; 18:17065-17074. [PMID: 38885193 DOI: 10.1021/acsnano.4c03630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2024]
Abstract
Polaritons, hybrid light and matter waves, offer a platform for subwavelength on-chip light manipulation. Recent works on planar refraction and focusing of polaritons all rely on heterogeneous components with different refractive indices. A fundamental question, thus, arises whether it is possible to configure two-dimensional monolithic polariton lenses based on a single medium. Here, we design and fabricate a type of monolithic polariton lens by directly sculpting an individual hyperbolic van der Waals crystal. The in-plane polariton focusing through sculptured step-terraces is triggered by geometry-induced symmetry breaking of momentum matching in polariton refractions. We show that the monolithic polariton lenses can be robustly tuned by the rise of van der Waals terraces and their curvatures, achieving a subwavelength focusing resolution down to 10% of the free-space light wavelength. Fusing with transformation optics, monolithic polariton lenses with gradient effective refractive indices, such as Luneburg lenses and Maxwell's fisheye lenses, are expected by sculpting polaritonic structures with gradually varied depths. Our results bear potential in planar subwavelength lenses, integrated optical circuits, and photonic chips.
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Affiliation(s)
- Yingjie Wu
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, China
- International Joint Innovation Centre, Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining 314400, China
- Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua 321099, China
| | - Jingying Liu
- Macao Institute of Materials Science and Engineering (MIMSE), Faculty of Innovation Engineering, Macau University of Science and Technology, Taipa, Macao 999078, China
- Department of Materials Science and Engineering, Monash University, VIC, Clayton 3800, Australia
| | - Wenzhi Yu
- Songshan Lake Materials Laboratory, Dongguan 523000, China
| | - Tan Zhang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore
| | - Haoran Mu
- Songshan Lake Materials Laboratory, Dongguan 523000, China
| | - Guangyuan Si
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton 3168, Australia
| | - Zhenyang Cui
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, China
- International Joint Innovation Centre, Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining 314400, China
- Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua 321099, China
| | - Shenghuang Lin
- Songshan Lake Materials Laboratory, Dongguan 523000, China
| | - Bin Zheng
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, China
- International Joint Innovation Centre, Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining 314400, China
- Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua 321099, China
| | - Cheng-Wei Qiu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore
| | - Hongsheng Chen
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 311215, China
- International Joint Innovation Centre, Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining 314400, China
- Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua 321099, China
| | - Qingdong Ou
- Macao Institute of Materials Science and Engineering (MIMSE), Faculty of Innovation Engineering, Macau University of Science and Technology, Taipa, Macao 999078, China
- Department of Materials Science and Engineering, Monash University, VIC, Clayton 3800, Australia
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton 3168, Australia
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4
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Liu M, Zhao W, Wang Y, Huo P, Zhang H, Lu YQ, Xu T. Achromatic and Coma-Corrected Hybrid Meta-Optics for High-Performance Thermal Imaging. NANO LETTERS 2024; 24:7609-7615. [PMID: 38861682 DOI: 10.1021/acs.nanolett.4c01218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2024]
Abstract
Long-wave infrared (LWIR) imaging, or thermal imaging, is widely applied in night vision and security monitoring. However, the widespread use of LWIR imagers is impeded by their bulky size, considerable weight, and high cost. While flat meta-optics present a potential solution to these limitations, existing pure LWIR meta-optics face constraints such as severe chromatic or coma aberrations. Here, we introduce an approach utilizing large-scale hybrid meta-optics to address these challenges and demonstrate the achromatic, coma-corrected, and polarization-insensitive thermal imaging. The hybrid metalens doublet is composed of a metasurface corrector and a refractive lens, featuring a full field-of-view angle surpassing 20° within the 8-12 μm wavelength range. Employing this hybrid metalens doublet, we showcase high-performance thermal imaging capabilities both indoors and outdoors, effectively capturing ambient thermal radiation. The proposed hybrid metalens doublet holds considerable promise for advancing miniaturized, lightweight, and cost-effective LWIR optical imaging systems.
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Affiliation(s)
- Mingze Liu
- National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Nanjing University, Nanjing 210093, China
| | - Weixing Zhao
- National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Nanjing University, Nanjing 210093, China
| | - Yilin Wang
- National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Nanjing University, Nanjing 210093, China
| | - Pengcheng Huo
- National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Nanjing University, Nanjing 210093, China
| | - Hui Zhang
- National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Nanjing University, Nanjing 210093, China
| | - Yan-Qing Lu
- National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Nanjing University, Nanjing 210093, China
| | - Ting Xu
- National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Nanjing University, Nanjing 210093, China
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5
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Hu J, Liang Z, Zhou P, Liu L, Hu G, Du P, Ye M. Integrated optical rotation detection scheme for chip-scale atomic magnetometer empowered by silicon-rich SiNx metalens. OPTICS LETTERS 2024; 49:3364-3367. [PMID: 38875621 DOI: 10.1364/ol.527932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 05/20/2024] [Indexed: 06/16/2024]
Abstract
High-performance atomic magnetometers (AMs) rely on the measurement of optical rotation, which requires a set of bulky polarization optics that limit their applications in scenarios where portability and compactness are necessary. In this study, a miniaturized AM is constructed based on a cubic 87Rb vapor cell and monolithic metalens, which provides an integrated scheme to achieve optical rotation detection induced by the circular birefringence of polarized atoms. The designed metalens achieves polarization splitting with deflection angles of ±10∘ and focusing with efficiencies of approximately 30% for orthogonal linear polarizations. The sensitivity of our compact device is ∼30 fT/Hz1/2 with a dynamic range of around ±1.45 nT. We envision that the presented approach paves the way for the chip integration of emerging atomic devices, which are in demand for applications such as biomagnetic imaging and portable atomic gyroscopes.
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Liu L, Liu W, Wang F, Peng X, Choi DY, Cheng H, Cai Y, Chen S. Ultra-robust informational metasurfaces based on spatial coherence structures engineering. LIGHT, SCIENCE & APPLICATIONS 2024; 13:131. [PMID: 38834550 DOI: 10.1038/s41377-024-01485-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 04/25/2024] [Accepted: 05/15/2024] [Indexed: 06/06/2024]
Abstract
Optical information transmission is vital in modern optics and photonics due to its concurrent and multi-dimensional nature, leading to tremendous applications such as optical microscopy, holography, and optical sensing. Conventional optical information transmission technologies suffer from bulky optical setup and information loss/crosstalk when meeting scatterers or obstacles in the light path. Here, we theoretically propose and experimentally realize the simultaneous manipulation of the coherence lengths and coherence structures of the light beams with the disordered metasurfaces. The ultra-robust optical information transmission and self-reconstruction can be realized by the generated partially coherent beam with modulated coherence structure even 93% of light is recklessly obstructed during light transmission, which brings new light to robust optical information transmission with a single metasurface. Our method provides a generic principle for the generalized coherence manipulation on the photonic platform and displays a variety of functionalities advancing capabilities in optical information transmission such as meta-holography and imaging in disordered and perturbative media.
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Affiliation(s)
- Leixin Liu
- Shandong Provincial Engineering and Technical Center of Light Manipulations, Collaborative Innovation Center of Light Manipulation and Applications, Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan, 250014, China
| | - Wenwei Liu
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics, School of Materials Science and Engineering, Smart Sensing Interdisciplinary Science Center, Nankai University, Tianjin, 300071, China.
| | - Fei Wang
- School of Physical Science and Technology, Soochow University, Suzhou, 215006, China
| | - Xiaofeng Peng
- Shandong Provincial Engineering and Technical Center of Light Manipulations, Collaborative Innovation Center of Light Manipulation and Applications, Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan, 250014, China
| | - Duk-Yong Choi
- Laser Physics Centre, Research School of Physics, Australian National University, Canberra, ACT, 2601, Australia
| | - Hua Cheng
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics, School of Materials Science and Engineering, Smart Sensing Interdisciplinary Science Center, Nankai University, Tianjin, 300071, China
| | - Yangjian Cai
- Shandong Provincial Engineering and Technical Center of Light Manipulations, Collaborative Innovation Center of Light Manipulation and Applications, Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan, 250014, China.
| | - Shuqi Chen
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics, School of Materials Science and Engineering, Smart Sensing Interdisciplinary Science Center, Nankai University, Tianjin, 300071, China.
- The Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, 030006, China.
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7
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Luo Y, Ye W, Zhou L, Xie J. Manipulating terahertz guided wave excitation with Fabry-Perot cavity-assisted metasurfaces. OPTICS EXPRESS 2024; 32:21216-21229. [PMID: 38859481 DOI: 10.1364/oe.525377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 05/13/2024] [Indexed: 06/12/2024]
Abstract
Metasurfaces are emerging as powerful tools for manipulating complex light fields, offering enhanced control in free space and on-chip waveguide applications. Their ability to customize refractive indices and dispersion properties opens up new possibilities in light guiding, yet their efficiency in exciting guided waves, particularly through metallic structures, is not fully explored. Here, we present a new method for exciting terahertz (THz) guided waves using Fabry-Perot (FP) cavity-assisted metasurfaces that enable spin-selective directional coupling and mode selection. Our design uses a substrate-free ridge silicon THz waveguide with air cladding and a supporting slab, incorporating placed metallic metasurfaces to exploit their unique interaction with the guided waves. With the silicon thin layer and air serving as an FP cavity, THz waves enter from the bottom of the device, thereby intensifying the impact of the metasurfaces. The inverse-structured complementary metasurface could enhance excitation performance. We demonstrate selective excitation of TE00 and TE10 modes with directional control, confirmed through simulations and experimental validations using a THz vector network analyzer (VNA) system. This work broadens the potential of metasurfaces for advanced THz waveguide technologies.
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8
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Henning AJ, Martin H, Jiang X. A method to efficiently and rapidly approximate the vectorial fields generated by large area metasurfaces. OPTICS EXPRESS 2024; 32:21345-21357. [PMID: 38859490 DOI: 10.1364/oe.520731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 04/22/2024] [Indexed: 06/12/2024]
Abstract
In order to calculate the electromagnetic fields that are produced after light passes through a metasurface, simulation methods such as the Finite-Difference Time-Domain method are often employed. While these provide a good approximation to the fields, the level of detail at which the volume of space that the light is propagating in needs to be modelled and the time for which simulations need to run, mean that as the area of the metasurface is increased these simulations rapidly become unwieldy. In this paper we show how the result of a FDTD simulation of a unit cell can be used to generate a good approximation of the vectorial field that large area metasurfaces will generate, but using a fraction of the computational resources. This approach can provide an intermediate design step, allowing potentially interesting designs to be rapidly identified or discarded.
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9
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Yang J, Hakala TK, Friberg AT. Dual perfect vectorial vortex beam generation with a single spin-multiplexed metasurface. OPTICS EXPRESS 2024; 32:20242-20255. [PMID: 38859139 DOI: 10.1364/oe.521179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 02/12/2024] [Indexed: 06/12/2024]
Abstract
Perfect optical vortex beams (POVBs) carrying orbital angular momentum (OAM) possess annular intensity profiles that are independent of the topological charge. Unlike POVBs, perfect vectorial vortex beams (PVVBs) not only carry orbital angular momentum but also exhibit spin angular momentum (SAM). By incorporating a Dammann vortex grating (DVG) on an all-dielectric metasurface, we demonstrate an approach to create a pair of PVVBs on a hybrid-order Poincaré sphere. Benefiting flexible phase modulation, by engineering the DVG and changing the input-beam state we are able to freely tailor the topological OAM and polarization eigenstates of the output PVVBs. This work demonstrates a versatile flat-optics platform for high-quality PVVB generation and may pave the way for applications in optical communication and quantum information processing.
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10
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Porfirev A, Khonina S, Porfirev D, Ivliev N. Structured polarized laser beams for controlled spiral-shaped mass transfer in azopolymer thin films. APPLIED OPTICS 2024; 63:3779-3784. [PMID: 38856340 DOI: 10.1364/ao.521196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 04/16/2024] [Indexed: 06/11/2024]
Abstract
We present an approach for the realization of controlled spiral-shaped mass transfer in azopolymer thin films and the fabrication of spiral microreliefs. For such laser processing, we propose to use light fields with structured polarization distributions generated by a transmissive spatial light modulator. The projection lithography approach is utilized, transferring the pattern directly to the surface of azopolymer thin films. The shaped polarization distributions with different dependencies of the polarization vector orientation on the azimuthal angle allow us to drive surface waves on the sample along a spiral trajectory. Additionally, the ability to control the concavity of the formed microreliefs is demonstrated. This approach can be effectively modified for the direct laser fabrication of more complex nano-/micro-elements as well as their arrays.
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11
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Carr Delgado H, Moradifar P, Chinn G, Levin CS, Dionne JA. Toward "super-scintillation" with nanomaterials and nanophotonics. NANOPHOTONICS 2024; 13:1953-1962. [PMID: 38745841 PMCID: PMC11090085 DOI: 10.1515/nanoph-2023-0946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Accepted: 03/18/2024] [Indexed: 05/16/2024]
Abstract
Following the discovery of X-rays, scintillators are commonly used as high-energy radiation sensors in diagnostic medical imaging, high-energy physics, astrophysics, environmental radiation monitoring, and security inspections. Conventional scintillators face intrinsic limitations including a low extraction efficiency of scintillated light and a low emission rate, leading to efficiencies that are less than 10 % for commercial scintillators. Overcoming these limitations will require new materials including scintillating nanomaterials ("nanoscintillators"), as well as new photonic approaches that increase the efficiency of the scintillation process, increase the emission rate of materials, and control the directivity of the scintillated light. In this perspective, we describe emerging nanoscintillating materials and three nanophotonic platforms: (i) plasmonic nanoresonators, (ii) photonic crystals, and (iii) high-Q metasurfaces that could enable high performance scintillators. We further discuss how a combination of nanoscintillators and photonic structures can yield a "super scintillator" enabling ultimate spatio-temporal resolution while enabling a significant boost in the extracted scintillation emission.
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Affiliation(s)
- Hamish Carr Delgado
- Department of Materials Science and Engineering, Stanford University, Stanford, CA94305, USA
| | - Parivash Moradifar
- Department of Materials Science and Engineering, Stanford University, Stanford, CA94305, USA
| | - Garry Chinn
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Craig S. Levin
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
| | - Jennifer A. Dionne
- Department of Materials Science and Engineering, Stanford University, Stanford, CA94305, USA
- Department of Radiology, Stanford University, Stanford, CA, 94305, USA
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12
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Hu S, Shi R, Wang B, Wei Y, Qi B, Zhou P. Full-Color Imaging System Based on the Joint Integration of a Metalens and Neural Network. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:715. [PMID: 38668209 PMCID: PMC11054357 DOI: 10.3390/nano14080715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 04/09/2024] [Accepted: 04/14/2024] [Indexed: 04/29/2024]
Abstract
Lenses have been a cornerstone of optical systems for centuries; however, they are inherently limited by the laws of physics, particularly in terms of size and weight. Because of their characteristic light weight, small size, and subwavelength modulation, metalenses have the potential to miniaturize and integrate imaging systems. However, metalenses still face the problem that chromatic aberration affects the clarity and accuracy of images. A high-quality image system based on the end-to-end joint optimization of a neural network and an achromatic metalens is demonstrated in this paper. In the multi-scale encoder-decoder network, both the phase characteristics of the metalens and the hyperparameters of the neural network are optimized to obtain high-resolution images. The average peak-signal-to-noise ratio (PSNR) and average structure similarity (SSIM) of the recovered images reach 28.53 and 0.83. This method enables full-color and high-performance imaging in the visible band. Our approach holds promise for a wide range of applications, including medical imaging, remote sensing, and consumer electronics.
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Affiliation(s)
- Shuling Hu
- School of Instrumentation and Optoelectronics Engineering, Beihang University, Beijing 100191, China; (S.H.); (B.Q.); (P.Z.)
| | - Ruixue Shi
- School of Instrumentation and Optoelectronics Engineering, Beihang University, Beijing 100191, China; (S.H.); (B.Q.); (P.Z.)
| | - Bin Wang
- Institute of Microelectronics of the Chinese Academy of Sciences, Beijing 100029, China
| | - Yuan Wei
- Photonic Institute of Microelectronics, Wenzhou 396 Xingping Road, Longwan District, Wenzhou 100029, China;
| | - Binzhi Qi
- School of Instrumentation and Optoelectronics Engineering, Beihang University, Beijing 100191, China; (S.H.); (B.Q.); (P.Z.)
| | - Peng Zhou
- School of Instrumentation and Optoelectronics Engineering, Beihang University, Beijing 100191, China; (S.H.); (B.Q.); (P.Z.)
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13
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Basilio-Ortiz JC, Moreno I. Unveiling Invariant Optical Properties of Dielectric Meta-Atoms. NANO LETTERS 2024. [PMID: 38604944 DOI: 10.1021/acs.nanolett.4c00742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
The phase-shift, transmittance, and polarization properties of meta-atoms are investigated, motivated by their use as building blocks of metasurfaces used in metalenses, holograms, and beam shaping. We studied dielectric nanorod meta-atoms of several geometries, which included cylinders, triangles, squares, hexagons, octagons, and truncated cones. By analyzing light propagation through these meta-atoms for three different wavelengths (632.8, 545, and 50 nm), we show that the phase-shift introduced is independent of their cross-section shape, contrary to the expected behavior. Additionally, we show that the polarization response is independent of the shape and that the transmittance is partially shape-independent. We identify a novel dependence of phase-shift on the effective cross-sectional area of meta-atoms. These meta-atom optical properties are independent of its shape if its geometry has a C3 or larger rotational symmetry. This optical invariance has significant implications for the topological optimization of flat optics.
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Affiliation(s)
- J Carlos Basilio-Ortiz
- Unidad Académica de Ciencia y Tecnología de la Luz y la Materia, UAZ, Zacatecas 98060, Mexico
| | - Ivan Moreno
- Unidad Académica de Ciencia y Tecnología de la Luz y la Materia, UAZ, Zacatecas 98060, Mexico
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14
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Vanmol K, Abdul Nazar AA, Thienpont H, Ferranti F, Van Erps J. Fabrication of multilevel metalenses using multiphoton lithography: from design to evaluation. OPTICS EXPRESS 2024; 32:10190-10203. [PMID: 38571236 DOI: 10.1364/oe.514237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 02/16/2024] [Indexed: 04/05/2024]
Abstract
We present a procedure for the design of multilevel metalenses and their fabrication with multiphoton-based direct laser writing. This work pushes this fast and versatile fabrication technique to its limits in terms of achievable feature size dimensions for the creation of compact high-numerical aperture metalenses on flat substrates and optical fiber tips. We demonstrate the design of metalenses with various numerical apertures up to 0.96, and optimize the fabrication process towards nanostructure shape reproducibility. We perform optical characterization of the metalenses towards spot size, focusing efficiency, and optical functionality with a fiber beam collimation design, and compare their performance with refractive and diffractive counterparts fabricated with the same technology.
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15
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Ding X, Zhao Z, Xie P, Cai D, Meng F, Wang C, Wu Q, Liu J, Burokur SN, Hu G. Metasurface-Based Optical Logic Operators Driven by Diffractive Neural Networks. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2308993. [PMID: 38032696 DOI: 10.1002/adma.202308993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 11/20/2023] [Indexed: 12/01/2023]
Abstract
In this paper, a novel optical logic operator based on the multifunctional metasurface driven by all-optical diffractive neural network is reported, which can perform four principal quantum logic operations (Pauli-X, Pauli-Y, Pauli-Z, and Hadamard gates). The two ground states| 0 ⟩ $|0 \rangle $ and| 1 ⟩ $|1 \rangle $ are characterized by two orthogonal linear polarization states. The proposed spatial- and polarization-multiplexed all-optical diffractive neural network only contains a hidden layer physically mapped as a metasurface with simple and compact unit cells, which dramatically reduces the volume and computing resources required for the system. The designed optical quantum operator is proven to achieve high fidelities for all four quantum logical gates, up to 99.96% numerically and 99.88% experimentally. The solution will facilitate the construction of large-scale optical quantum computing systems and scalable optical quantum devices.
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Affiliation(s)
- Xumin Ding
- Advanced Microscopy and Instrumentation Research Center, School of Instrumentation Science and Engineering, Harbin Institute of Technology, Harbin, 150080, China
| | - Zihan Zhao
- Advanced Microscopy and Instrumentation Research Center, School of Instrumentation Science and Engineering, Harbin Institute of Technology, Harbin, 150080, China
| | - Peng Xie
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Dayu Cai
- Department of Microwave Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Fanyi Meng
- Department of Microwave Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Cong Wang
- Department of Microwave Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Qun Wu
- Department of Microwave Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Jian Liu
- Advanced Microscopy and Instrumentation Research Center, School of Instrumentation Science and Engineering, Harbin Institute of Technology, Harbin, 150080, China
| | | | - Guangwei Hu
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
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16
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Mao X, Yu G, Zhao Y, Wei B, Li Z, Yang F, Wang X. Design and simulation of an extreme ultraviolet metalens based on the Pancharatnam-Berry phase. APPLIED OPTICS 2024; 63:1867-1874. [PMID: 38437291 DOI: 10.1364/ao.511899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Accepted: 02/06/2024] [Indexed: 03/06/2024]
Abstract
Extreme ultraviolet (EUV) radiation plays a key role in the fields of material science, attosecond metrology, and lithography. However, the reflective optical components typically used in EUV systems contribute to their bulky size, weight, and increased costs for fabrication. In this paper, we theoretically investigate transmissive metalens designs capable of focusing the EUV light based on the Pancharatnam-Berry phase. The designed metalens is composed of nanoscale elliptical holes, which can guide and manipulate EUV light due to the higher refractive index of the vacuum holes compared to that of the surrounding material. We designed an EUV metalens with a diameter of 10 µm, which supports a focal length of 24 µm and a numerical aperture of up to 0.2. It can focus 55-nm EUV incident light to a diffraction-limited spot, and the focusing efficiency is calculated to be as high as about 7% over a broad EUV frequency range (50-65 nm). This study reveals the possibility of applying a dielectric metalens in the EUV region without a transmissive optical material.
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17
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Zhou C, Martin OJF, Charbon E. Planar 16-band metasurface-enhanced spectral filter for integrated image sensing. OPTICS EXPRESS 2024; 32:7463-7472. [PMID: 38439425 DOI: 10.1364/oe.515675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 02/02/2024] [Indexed: 03/06/2024]
Abstract
We study theoretically and demonstrate experimentally a 16-band narrow band wavelength selective filter in the near-infrared range. The combination of a pair of distributed Bragg reflectors with a sub-wavelength grating metasurface embedded in the intra-cavity provides a narrow response which can be tuned by adjusting the geometry of the sub-wavelength grating metasurface. The key advantage of this approach is its ease of fabrication, where the spectral response is tuned by merely changing the grating period, resulting in a perfectly planar geometry that can be easily integrated with a broad variety of photodetectors, thus enabling attractive applications such as bio-imaging, time-of-flight sensors and LiDAR. The experimental results are supported by numerical simulations and effective medium theory that unveil the mechanisms that lead to the optical response of the device. It is also shown how the polarization dependence of the structure can be used to determine very accurately the polarization of incoming light.
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18
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Jang J, Park M, Park Y. Non-interleaved chiral metasurfaces and neural networks enhance the spatial resolution of polarimetry. LIGHT, SCIENCE & APPLICATIONS 2024; 13:53. [PMID: 38378579 PMCID: PMC10879079 DOI: 10.1038/s41377-024-01397-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Non-interleaved chiral metasurfaces for high-spatial-resolution polarimetry are proposed and demonstrated. Furthermore, a convolutional neural network is incorporated to analyze interferometric images with the polarization state of light, and it results in accurate Stokes parameters.
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Affiliation(s)
- Jaewon Jang
- Department of Physics, Chungnam National University, Daejeon, 34134, Korea
- Institute of Quantum Systems, Chungnam National University, Daejeon, 34134, Korea
| | - Minsu Park
- Department of Physics, Chungnam National University, Daejeon, 34134, Korea
- Institute of Quantum Systems, Chungnam National University, Daejeon, 34134, Korea
| | - Yeonsang Park
- Department of Physics, Chungnam National University, Daejeon, 34134, Korea.
- Institute of Quantum Systems, Chungnam National University, Daejeon, 34134, Korea.
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19
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Mascaretti L, Chen Y, Henrotte O, Yesilyurt O, Shalaev VM, Naldoni A, Boltasseva A. Designing Metasurfaces for Efficient Solar Energy Conversion. ACS PHOTONICS 2023; 10:4079-4103. [PMID: 38145171 PMCID: PMC10740004 DOI: 10.1021/acsphotonics.3c01013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 11/01/2023] [Accepted: 11/01/2023] [Indexed: 12/26/2023]
Abstract
Metasurfaces have recently emerged as a promising technological platform, offering unprecedented control over light by structuring materials at the nanoscale using two-dimensional arrays of subwavelength nanoresonators. These metasurfaces possess exceptional optical properties, enabling a wide variety of applications in imaging, sensing, telecommunication, and energy-related fields. One significant advantage of metasurfaces lies in their ability to manipulate the optical spectrum by precisely engineering the geometry and material composition of the nanoresonators' array. Consequently, they hold tremendous potential for efficient solar light harvesting and conversion. In this Review, we delve into the current state-of-the-art in solar energy conversion devices based on metasurfaces. First, we provide an overview of the fundamental processes involved in solar energy conversion, alongside an introduction to the primary classes of metasurfaces, namely, plasmonic and dielectric metasurfaces. Subsequently, we explore the numerical tools used that guide the design of metasurfaces, focusing particularly on inverse design methods that facilitate an optimized optical response. To showcase the practical applications of metasurfaces, we present selected examples across various domains such as photovoltaics, photoelectrochemistry, photocatalysis, solar-thermal and photothermal routes, and radiative cooling. These examples highlight the ways in which metasurfaces can be leveraged to harness solar energy effectively. By tailoring the optical properties of metasurfaces, significant advancements can be expected in solar energy harvesting technologies, offering new practical solutions to support an emerging sustainable society.
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Affiliation(s)
- Luca Mascaretti
- Czech
Advanced Technology and Research Institute, Regional Centre of Advanced
Technologies and Materials, Palacký
University Olomouc, Šlechtitelů 27, 77900 Olomouc, Czech Republic
- Department
of Physical Electronics, Faculty of Nuclear Sciences and Physical
Engineering, Czech Technical University
in Prague, Břehová
7, 11519 Prague, Czech Republic
| | - Yuheng Chen
- Elmore
Family School of Electrical and Computer Engineering, Birck Nanotechnology
Center, and Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, Indiana 47907, United States
- The
Quantum Science Center (QSC), a National Quantum Information Science
Research Center of the U.S. Department of Energy (DOE), Oak Ridge, Tennessee 37931, United States
| | - Olivier Henrotte
- Czech
Advanced Technology and Research Institute, Regional Centre of Advanced
Technologies and Materials, Palacký
University Olomouc, Šlechtitelů 27, 77900 Olomouc, Czech Republic
| | - Omer Yesilyurt
- Elmore
Family School of Electrical and Computer Engineering, Birck Nanotechnology
Center, and Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, Indiana 47907, United States
- The
Quantum Science Center (QSC), a National Quantum Information Science
Research Center of the U.S. Department of Energy (DOE), Oak Ridge, Tennessee 37931, United States
| | - Vladimir M. Shalaev
- Elmore
Family School of Electrical and Computer Engineering, Birck Nanotechnology
Center, and Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, Indiana 47907, United States
- The
Quantum Science Center (QSC), a National Quantum Information Science
Research Center of the U.S. Department of Energy (DOE), Oak Ridge, Tennessee 37931, United States
| | - Alberto Naldoni
- Department
of Chemistry and NIS Centre, University
of Turin, Turin 10125, Italy
| | - Alexandra Boltasseva
- Elmore
Family School of Electrical and Computer Engineering, Birck Nanotechnology
Center, and Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, Indiana 47907, United States
- The
Quantum Science Center (QSC), a National Quantum Information Science
Research Center of the U.S. Department of Energy (DOE), Oak Ridge, Tennessee 37931, United States
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20
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Huang PS, Chu CH, Huang SH, Su HP, Tanaka T, Wu PC. Varifocal Metalenses: Harnessing Polarization-Dependent Superposition for Continuous Focal Length Control. NANO LETTERS 2023; 23:10432-10440. [PMID: 37956251 DOI: 10.1021/acs.nanolett.3c03056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Traditional varifocal lenses are bulky and mechanically complex. Emerging active metalenses promise compactness and design flexibility but face issues like mechanical tuning reliability and nonlinear focal length tuning due to additional medium requirements. In this work, we propose a varifocal metalens design based on superimposing light intensity distributions from two orthogonal polarization states. This approach enables continuous and precise focal length control within the visible spectrum, while maintaining relatively high focusing efficiencies (∼41% in simulation and ∼28% in measurement) and quality. In experimental validation, the metalens exhibited flexible tunability, with the focal length continuously adjustable between two spatial positions upon variation of the incident polarization angle. The MTF results showed high contrast reproduction and sharp imaging, with a Strehl ratio of >0.7 for all polarization angles. With compactness, design flexibility, and high focusing quality, the proposed varifocal metalens holds potential for diverse applications, advancing adaptive and versatile optical devices.
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Affiliation(s)
- Po-Sheng Huang
- Department of Photonics, National Cheng Kung University, Tainan 70101, Taiwan
| | - Cheng Hung Chu
- YongLin Institute of Health, National Taiwan University, Taipei 10672, Taiwan
| | - Shih-Hsiu Huang
- Department of Photonics, National Cheng Kung University, Tainan 70101, Taiwan
| | - Hsiu-Ping Su
- Department of Photonics, National Cheng Kung University, Tainan 70101, Taiwan
| | - Takuo Tanaka
- Innovative Photon Manipulation Research Team, RIKEN Center for Advanced Photonics, Saitama 351-0198, Japan
- Metamaterials Laboratory, RIKEN Cluster for Pioneering Research, Saitama 351-0198, Japan
- Institute of Post-LED Photonics, Tokushima University, 2-1 Minamijosanjima-cho, Tokushima, Tokushima 770-8506, Japan
| | - Pin Chieh Wu
- Department of Photonics, National Cheng Kung University, Tainan 70101, Taiwan
- Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan 70101, Taiwan
- Meta-nanoPhotonics Center, National Cheng Kung University, Tainan 70101, Taiwan
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21
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Chen Q, Gao Y, Pian S, Ma Y. Theory and Fundamental Limit of Quasiachromatic Metalens by Phase Delay Extension. PHYSICAL REVIEW LETTERS 2023; 131:193801. [PMID: 38000403 DOI: 10.1103/physrevlett.131.193801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 10/03/2023] [Indexed: 11/26/2023]
Abstract
The periodic extension of phase difference is commonly applied in device design to obtain phase compensation beyond the system's original phase modulation capabilities. Based on this extension approach, we propose the application of quasiphase delay matching to extend the range of dispersion compensation for meta-atoms with limited height. Our theory expands the limit of frequency bandwidth coverage and relaxes the constraints of aperture, NA, and bandwidth for metalenses. By applying the uncertainty principle, we explain the fundamental limit of this achromatic bandwidth and obtain the achromatic spectrum using perturbation analysis. To demonstrate the effectiveness of this extended limit, we simulate a quasiachromatic metalens with a diameter of 2 mm and a NA of 0.55 in the range of 400-1500 nm. Our findings provide a novel theory for correcting chromatic aberration in large-diameter ultrawide bandwidth devices.
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Affiliation(s)
- Qikai Chen
- State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou, 311200, China
| | - Yubin Gao
- State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou, 311200, China
| | - Sijie Pian
- State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou, 311200, China
| | - Yaoguang Ma
- State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310058, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou, 311200, China
- Jiaxing Key Laboratory of Photonic Sensing and Intelligent Imaging, Intelligent Optics and Photonics Research Center, Jiaxing Research Institute, Zhejiang University, Jiaxing, 314000, China
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22
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Hou T, Li X, Luo H, Hao Y, Chu H, Lai Y. Optically-transparent meta-window for wireless communication. OPTICS EXPRESS 2023; 31:38949-38957. [PMID: 38017985 DOI: 10.1364/oe.504238] [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: 10/21/2023] [Indexed: 11/30/2023]
Abstract
Circumventing the attenuation of microwaves during the propagation is of prime importance to wireless communication towards higher carrier frequencies. Here, we propose a scheme of wireless communications via a functionalized meta-window constructed by an optically-transparent metasurface (OTM) consisting of indium tin oxide (ITO) patterns. When the signal is weak, the OTM can significantly strengthen the signal by focusing the incoming waves towards the windowsill, thus substantially enhancing the network speed. The intensity enhancement of microwaves at 5 GHz via an OTM is verified by both numerical simulations and experiments. Furthermore, the ability to increase the data transfer rate in a 5-GHz-WiFi environment is directly demonstrated. Our work demonstrates the feasibility of applying an optically-transparent meta-window for enhancing wireless communications.
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23
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So S, Mun J, Park J, Rho J. Revisiting the Design Strategies for Metasurfaces: Fundamental Physics, Optimization, and Beyond. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2206399. [PMID: 36153791 DOI: 10.1002/adma.202206399] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/13/2022] [Indexed: 06/16/2023]
Abstract
Over the last two decades, the capabilities of metasurfaces in light modulation with subwavelength thickness have been proven, and metasurfaces are expected to miniaturize conventional optical components and add various functionalities. Herein, various metasurface design strategies are reviewed thoroughly. First, the scalar diffraction theory is revisited to provide the basic principle of light propagation. Then, widely used design methods based on the unit-cell approach are discussed. The methods include a set of simplified steps, including the phase-map retrieval and meta-atom unit-cell design. Then, recently emerging metasurfaces that may not be accurately designed using unit-cell approach are introduced. Unconventional metasurfaces are examined where the conventional design methods fail and finally potential design methods for such metasurfaces are discussed.
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Affiliation(s)
- Sunae So
- Graduate School of Artificial Intelligence, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Jungho Mun
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Junghyun Park
- Samsung Advanced Institute of Technology, Samsung Electronics, Suwon, 16678, Republic of Korea
| | - Junsuk Rho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics, Pohang, 37673, Republic of Korea
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24
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Sosa-Sánchez CT, Téllez-Limón R. Plasmonic Metalens to Generate an Airy Beam. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2576. [PMID: 37764605 PMCID: PMC10537606 DOI: 10.3390/nano13182576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 09/07/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023]
Abstract
Airy beams represent an important type of non-diffracting beams-they are the only non-diffracting wave in one dimension, and thus they can be produced with a cylindrical geometry that modifies a wavefront in one dimension. In this paper, we show the design of a cylindrical plasmonic metalens consisting of an array of nanoslits in a gold thin layer that modulates the phase of a Gaussian beam to generate an airy beam propagating in free space. Based on the numerical results, we show that it is possible to generate an airy beam by only matching the phase of wavefronts coming out from the array of gold nanoslits to the airy beam phase at plane z=0. We numerically demonstrate that the airy beam exhibits bending over propagation and self-healing properties. The transmission efficiency is around 60%. The simplicity of the proposed structure open new perspectives in the design of flat metasurfaces for light-focusing applications.
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Affiliation(s)
- Citlalli T. Sosa-Sánchez
- Unidad Foránea Monterrey, Centro de Investigación Científica y de Educación Superior de Ensenada, Alianza Centro 504, PIIT, Apodaca 66629, Mexico;
| | - Ricardo Téllez-Limón
- CONAHCYT—Unidad Foránea Monterrey, Centro de Investigación Científica y de Educación Superior de Ensenada, Alianza Centro 504, PIIT, Apodaca 66629, Mexico
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25
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Wang Y, Yang Z, Hu P, Hossain S, Liu Z, Ou TH, Ye J, Wu W. End-to-End Diverse Metasurface Design and Evaluation Using an Invertible Neural Network. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2561. [PMID: 37764590 PMCID: PMC10534592 DOI: 10.3390/nano13182561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 09/11/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023]
Abstract
Employing deep learning models to design high-performance metasurfaces has garnered significant attention due to its potential benefits in terms of accuracy and efficiency. A deep learning-based metasurface design framework typically comprises a forward prediction path for predicting optical responses and a backward retrieval path for generating geometrical configurations. In the forward design path, a specific geometrical configuration corresponds to a unique optical response. However, in the inverse design path, a single performance metric can correspond to multiple potential designs. This one-to-many mapping poses a significant challenge for deep learning models and can potentially impede their performance. Although representing the inverse path as a probabilistic distribution is a widely adopted method for tackling this problem, accurately capturing the posterior distribution to encompass all potential solutions remains an ongoing challenge. Furthermore, in most pioneering works, the forward and backward paths are captured using separate models. However, the knowledge acquired from the forward path does not contribute to the training of the backward model. This separation of models adds complexity to the system and can hinder the overall efficiency and effectiveness of the design framework. Here, we utilized an invertible neural network (INN) to simultaneously model both the forward and inverse process. Unlike other frameworks, INN focuses on the forward process and implicitly captures a probabilistic model for the inverse process. Given a specific optical response, the INN enables the recovery of the complete posterior over the parameter space. This capability allows for the generation of novel designs that are not present in the training data. Through the integration of the INN with the angular spectrum method, we have developed an efficient and automated end-to-end metasurface design and evaluation framework. This novel approach eliminates the need for human intervention and significantly speeds up the design process. Utilizing this advanced framework, we have effectively designed high-efficiency metalenses and dual-polarization metasurface holograms. This approach extends beyond dielectric metasurface design, serving as a general method for modeling optical inverse design problems in diverse optical fields.
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Affiliation(s)
- Yunxiang Wang
- Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Ziyuan Yang
- The High School Affiliated to Renmin University of China, CUIWEI Campus, Beijing 100086, China
| | - Pan Hu
- Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Sushmit Hossain
- Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Zerui Liu
- Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Tse-Hsien Ou
- Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Jiacheng Ye
- Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Wei Wu
- Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA
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26
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Born B, Lee SH, Song JH, Lee JY, Ko W, Brongersma ML. Off-axis metasurfaces for folded flat optics. Nat Commun 2023; 14:5602. [PMID: 37699876 PMCID: PMC10497541 DOI: 10.1038/s41467-023-41123-x] [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: 02/09/2023] [Accepted: 08/15/2023] [Indexed: 09/14/2023] Open
Abstract
The overall size of an optical system is limited by the volume of the components and the internal optical path length. To reach the limits of miniaturization, it is possible to reduce both component volume and path length by combining the concepts of metasurface flat optics and folded optics. In addition to their subwavelength component thickness, metasurfaces enable bending conventional folded geometries off axis beyond the law of reflection. However, designing metasurfaces for highly off-axis illumination with visible light in combination with a high numerical aperture is non-trivial. In this case, traditional designs with gradient metasurfaces exhibit low diffraction efficiencies and require the use of deep-subwavelength, high-index, and high-aspect-ratio semiconductor nanostructures that preclude inexpensive, large-area nanofabrication. Here, we describe a design approach that enables the use of low-index (n ≈ 1.5), low-aspect ratio structures for off-axis metagratings that can redirect and focus visible light (λ = 532 nm) with near-unity efficiency. We show that fabricated optical elements offer a very large angle-of-view (110°) and lend themselves to scalable fabrication by nano-imprint lithography.
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Affiliation(s)
- Brandon Born
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA, USA
| | - Sung-Hoon Lee
- Samsung Advanced Institute of Technology, Samsung Electronics Co. Ltd., Samsung-ro 130, Yeongtong-gu, Suwon-si, Gyeonggi-do, 16678, South Korea
| | - Jung-Hwan Song
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA, USA
| | - Jeong Yub Lee
- Samsung Advanced Institute of Technology, Samsung Electronics Co. Ltd., Samsung-ro 130, Yeongtong-gu, Suwon-si, Gyeonggi-do, 16678, South Korea
| | - Woong Ko
- Samsung Advanced Institute of Technology, Samsung Electronics Co. Ltd., Samsung-ro 130, Yeongtong-gu, Suwon-si, Gyeonggi-do, 16678, South Korea
| | - Mark L Brongersma
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA, USA.
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27
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Du XJ, Tang XT, Xie B, Ma L, Hu ML, He J, Yang ZJ. Turning whispering-gallery-mode responses through Fano interferences in coupled all-dielectric block-disk cavities. OPTICS EXPRESS 2023; 31:29380-29391. [PMID: 37710739 DOI: 10.1364/oe.500562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 08/11/2023] [Indexed: 09/16/2023]
Abstract
Here, we theoretically demonstrate a strategy for efficiently turning whispering-gallery-mode (WGM) responses of a subwavelength dielectric disk through their near-field couplings with common low-order electromagnetic resonances of a dielectric block. Both simulations and an analytical coupled oscillator model show that the couplings are Fano interferences between dark high-quality WGMs and bright modes of the block. The responses of a WGM in the coupled system are highly dependent on the strengths and the relative phases of the block modes, the coupling strength, and the decay rate of the WGM. The WGM responses of coupled systems can exceed that of the individual disk. In addition, such a configuration will also facilitate the excitation of WGMs by a normal incident plane wave in experiments. These results could enable new applications for enhancing light-matter interactions.
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Yao D, Connolly PWR, Sykes AJ, Shah YD, Accarino C, Grant J, Cumming DRS, Buller GS, McLaughlin S, Altmann Y. Rapid single-photon color imaging of moving objects. OPTICS EXPRESS 2023; 31:26610-26625. [PMID: 37710518 DOI: 10.1364/oe.493172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 07/12/2023] [Indexed: 09/16/2023]
Abstract
This paper outlines an experimental demonstration of a Bayesian image reconstruction approach to achieve rapid single-photon color imaging of moving objects. The capacity to extract the color of objects is important in a variety of target identification and computer vision applications. Nonetheless, it remains challenging to achieve high-speed color imaging of moving objects in low-photon flux environments. The low-photon regime presents particular challenges for efficient spectral separation and identification, while unsupervised image reconstruction algorithms are often slow and computationally expensive. In this paper, we address both of these difficulties using a combination of hardware and computational solutions. We demonstrate color imaging using a Single-Photon Avalanche Diode (SPAD) detector array for rapid, low-light-level data acquisition, with an integrated color filter array (CFA) for efficient spectral unmixing. High-speed image reconstruction is achieved using a bespoke Bayesian algorithm to produce high-fidelity color videos. The analysis is conducted first on simulated data allowing different pixel formats and photon flux scenarios to be investigated. Experiments are then performed using a plasmonic metasurface-based CFA, integrated with a 64 × 64 pixel format SPAD array. Passive imaging is conducted using white-light illumination of multi-colored, moving targets. Intensity information is recorded in a series of 2D photon-counting SPAD frames, from which accurate color information is extracted using the fast Bayesian method introduced herein. The per-frame reconstruction rate proves to be hundreds of times faster than the previous computational method. Furthermore, this approach yields additional information in the form of uncertainty measures, which can be used to assist with imaging system optimization and decision-making in real-world applications. The techniques demonstrated point the way towards rapid video-rate single-photon color imaging. The developed Bayesian algorithm, along with more advanced SPAD technology and utilization of time-correlated single-photon counting (TCSPC) will permit live 3D, color videography in extremely low-photon flux environments.
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Xu P, Li X, Yang T, Xiao Y, Cheng X, Lou F, Zhang X, Huang H, Zhang X, Wang M, Xu H, Yuan X. Long-infrared dual-wavelength linear-polarization-multiplexed confocal metalens based on an all-silicon dielectric. OPTICS EXPRESS 2023; 31:26685-26696. [PMID: 37710523 DOI: 10.1364/oe.494599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 07/17/2023] [Indexed: 09/16/2023]
Abstract
The metalens has vast applications in biomedicine and industrial manufacturing due to their ultrathin structure and vital ability to manipulate the properties of light waves for long-infrared systems. However, it is difficult for metalens to achieve the confocal function with high focusing efficiency, wide wavelength bandwidth, and low structural complexity. Here, we propose and experimentally demonstrate an all-silicon dielectric metalens composed of arrays of minimalist meta-atoms with a single rectangular nanopillar arranged on a periodic square lattice substrate, which realizes the confocal function of the orthogonal-linear-polarized light with wavelengths of 10.6 µm and 9.3 µm, with focusing efficiencies of 64.94% and 60.03%, respectively. Also, it reveals nearly the diffraction-limited focusing performance. In addition, the metalens can realize precise long-infrared thermal imaging. Moreover, the proposed metalens is compatible with the standard complementary metal oxide semiconductor processes, which can effectively reduce the manufacturing cost and provide a feasible solution for developing planar integrated multifunctional micro-nanophotonic devices in the long-infrared field.
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30
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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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31
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Hua S, Wu JH. Tailored diffractions of asymmetric columns and symmetric rows in two-dimensional multi-element phase gratings. OPTICS EXPRESS 2023; 31:24363-24375. [PMID: 37475265 DOI: 10.1364/oe.495539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 06/27/2023] [Indexed: 07/22/2023]
Abstract
Two-dimensional multi-element phase gratings can be engineered to show an even symmetry along one direction while an odd symmetry along the other direction in terms of offset refractive indices in each unit cell. The interplay of such even and odd symmetries has been explored to tailor diffraction columns and rows on demand by making offset refractive indices to satisfy specific requirements and hence attain different types of destructive interference. The resultant tailoring effects include the directional column elimination, the grouped column elimination, and the directional column selection as well as the natural row absence, the grouped row elimination, and the central row selection.
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32
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Shi X, Kurman Y, Shentcis M, Wong LJ, García de Abajo FJ, Kaminer I. Free-electron interactions with van der Waals heterostructures: a source of focused X-ray radiation. LIGHT, SCIENCE & APPLICATIONS 2023; 12:148. [PMID: 37321995 DOI: 10.1038/s41377-023-01141-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 03/06/2023] [Accepted: 03/30/2023] [Indexed: 06/17/2023]
Abstract
The science and technology of X-ray optics have come far, enabling the focusing of X-rays for applications in high-resolution X-ray spectroscopy, imaging, and irradiation. In spite of this, many forms of tailoring waves that had substantial impact on applications in the optical regime have remained out of reach in the X-ray regime. This disparity fundamentally arises from the tendency of refractive indices of all materials to approach unity at high frequencies, making X-ray-optical components such as lenses and mirrors much harder to create and often less efficient. Here, we propose a new concept for X-ray focusing based on inducing a curved wavefront into the X-ray generation process, resulting in the intrinsic focusing of X-ray waves. This concept can be seen as effectively integrating the optics to be part of the emission mechanism, thus bypassing the efficiency limits imposed by X-ray optical components, enabling the creation of nanobeams with nanoscale focal spot sizes and micrometer-scale focal lengths. Specifically, we implement this concept by designing aperiodic vdW heterostructures that shape X-rays when driven by free electrons. The parameters of the focused hotspot, such as lateral size and focal depth, are tunable as a function of an interlayer spacing chirp and electron energy. Looking forward, ongoing advances in the creation of many-layer vdW heterostructures open unprecedented horizons of focusing and arbitrary shaping of X-ray nanobeams.
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Affiliation(s)
- Xihang Shi
- Solid State Institute and Faculty of Electrical and Computer Engineering, Technion - Israel Institute of Technology, Haifa, 32000, Israel
| | - Yaniv Kurman
- Solid State Institute and Faculty of Electrical and Computer Engineering, Technion - Israel Institute of Technology, Haifa, 32000, Israel
| | - Michael Shentcis
- Solid State Institute and Faculty of Electrical and Computer Engineering, Technion - Israel Institute of Technology, Haifa, 32000, Israel
| | - Liang Jie Wong
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - F Javier García de Abajo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, 08860, Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, Barcelona, 08010, Spain
| | - Ido Kaminer
- Solid State Institute and Faculty of Electrical and Computer Engineering, Technion - Israel Institute of Technology, Haifa, 32000, Israel.
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Abstract
Optical metasurfaces supporting localized resonances have become a versatile platform for shaping the wavefront of light, but their low quality (Q-) factor modes inevitably modify the wavefront over extended momentum and frequency space, resulting in limited spectral and angular control. In contrast, periodic nonlocal metasurfaces have been providing great flexibility for both spectral and angular selectivity but with limited spatial control. Here, we introduce multiresonant nonlocal metasurfaces capable of shaping the spatial properties of light using several resonances with widely disparate Q-factors. In contrast to previous designs, the narrowband resonant transmission punctuates a broadband resonant reflection window enabled by a highly symmetric array, achieving simultaneous spectral filtering and wavefront shaping in the transmission mode. Through rationally designed perturbations, we realize nonlocal flat lenses suitable as compact band-pass imaging devices, ideally suited for microscopy. We further employ modified topology optimization to demonstrate high-quality-factor metagratings for extreme wavefront transformations with large efficiency.
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Affiliation(s)
- You Zhou
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, New York 10031, United States
| | - Shuwei Guo
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, New York 10031, United States
| | - Adam Christopher Overvig
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, New York 10031, United States
| | - Andrea Alù
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York, New York 10031, United States
- Physics Program, Graduate Center, City University of New York, New York, New York 10016, United States
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34
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Chung H, Hwang I, Yu J, Boehm G, Belkin MA, Lee J. Electrical Phase Modulation Based on Mid-Infrared Intersubband Polaritonic Metasurfaces. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2207520. [PMID: 37029461 DOI: 10.1002/advs.202207520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/24/2023] [Indexed: 06/04/2023]
Abstract
Electrically reconfigurable metasurfaces that overcome the static limitations in controlling the fundamental properties of scattered light are opening new avenues for functional flat optics. This work proposes and experimentally demonstrates electrically phase-tunable mid-infrared metasurfaces based on the polaritonic coupling of Stark-tunable intersubband transitions in semiconductor heterostructures and electromagnetic modes in plasmonic nanoresonators. In the applied voltage range of -3 to +3 V, the local phase tuning of the light reflects from the metasurface, which enables the electrical control of the polarization state and wavefront of the reflected wave. Electrical beam polarization control, electrical beam diffraction control, and electrical beam steering are experimentally demonstrated as applications for local phase tunability. The proposed electrically tunable metasurfaces can easily tune the operating wavelength and function at relatively low voltages, which will enable various applications in the mid-infrared region.
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Affiliation(s)
- Hyeongju Chung
- Department of Electrical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Inyong Hwang
- Department of Electrical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Jaeyeon Yu
- Department of Electrical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Gerhard Boehm
- Walter Schottky Institute, Technical University of Munich, 85748, Garching, Germany
| | - Mikhail A Belkin
- Walter Schottky Institute, Technical University of Munich, 85748, Garching, Germany
| | - Jongwon Lee
- Department of Electrical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
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35
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Nabben D, Kuttruff J, Stolz L, Ryabov A, Baum P. Attosecond electron microscopy of sub-cycle optical dynamics. Nature 2023:10.1038/s41586-023-06074-9. [PMID: 37258681 DOI: 10.1038/s41586-023-06074-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 04/12/2023] [Indexed: 06/02/2023]
Abstract
The primary step of almost any interaction between light and materials is the electrodynamic response of the electrons to the optical cycles of the impinging light wave on sub-wavelength and sub-cycle dimensions1. Understanding and controlling the electromagnetic responses of a material2-11 is therefore essential for modern optics and nanophotonics12-19. Although the small de Broglie wavelength of electron beams should allow access to attosecond and ångström dimensions20, the time resolution of ultrafast electron microscopy21 and diffraction22 has so far been limited to the femtosecond domain16-18, which is insufficient for recording fundamental material responses on the scale of the cycles of light1,2,10. Here we advance transmission electron microscopy to attosecond time resolution of optical responses within one cycle of excitation light23. We apply a continuous-wave laser24 to modulate the electron wave function into a rapid sequence of electron pulses, and use an energy filter to resolve electromagnetic near-fields in and around a material as a movie in space and time. Experiments on nanostructured needle tips, dielectric resonators and metamaterial antennas reveal a directional launch of chiral surface waves, a delay between dipole and quadrupole dynamics, a subluminal buried waveguide field and a symmetry-broken multi-antenna response. These results signify the value of combining electron microscopy and attosecond laser science to understand light-matter interactions in terms of their fundamental dimensions in space and time.
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Affiliation(s)
- David Nabben
- Fachbereich Physik, Universität Konstanz, Konstanz, Germany
| | - Joel Kuttruff
- Fachbereich Physik, Universität Konstanz, Konstanz, Germany
| | - Levin Stolz
- Fachbereich Physik, Universität Konstanz, Konstanz, Germany
| | - Andrey Ryabov
- Fachbereich Physik, Universität Konstanz, Konstanz, Germany.
| | - Peter Baum
- Fachbereich Physik, Universität Konstanz, Konstanz, Germany.
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36
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Wang M, Chen L, Choi DY, Huang S, Wang Q, Tu C, Cheng H, Tian J, Li Y, Chen S, Wang HT. Characterization of Orbital Angular Momentum Quantum States Empowered by Metasurfaces. NANO LETTERS 2023; 23:3921-3928. [PMID: 37102437 DOI: 10.1021/acs.nanolett.3c00554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Twisted photons can in principle carry a discrete unbounded amount of orbital angular momentum (OAM), which are of great significance for quantum communication and fundamental tests of quantum theory. However, the methods for characterization of the OAM quantum states present a fundamental limit for miniaturization. Metasurfaces can exploit new degrees of freedom to manipulate optical fields beyond the capabilities of bulk optics, opening a broad range of novel and superior applications in quantum photonics. Here we present a scheme to reconstruct the density matrix of the OAM quantum states of single photons with all-dielectric metasurfaces composed of birefringent meta-atoms. We have also measured the Schmidt number of the OAM entanglement by the multiplexing of multiple degrees of freedom. Our work represents a step toward the practical application of quantum metadevices for the measurement of OAM quantum states in free-space quantum imaging and communications.
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Affiliation(s)
- Min Wang
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics, Nankai University, Tianjin 300071, People's Republic of China
| | - Lieyu Chen
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics, Nankai University, Tianjin 300071, People's Republic of China
| | - Duk-Yong Choi
- Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra, Australian Central Territory 2601, Australia
- College of Information Science and Technology, Jinan University, Guangzhou 510632, People's Republic of China
| | - Shuangyin Huang
- National Laboratory of Solid State Microstructures and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Qiang Wang
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics, Nankai University, Tianjin 300071, People's Republic of China
| | - Chenghou Tu
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics, Nankai University, Tianjin 300071, People's Republic of China
| | - Hua Cheng
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics, Nankai University, Tianjin 300071, People's Republic of China
| | - Jianguo Tian
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics, Nankai University, Tianjin 300071, People's Republic of China
| | - Yongnan Li
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics, Nankai University, Tianjin 300071, People's Republic of China
| | - Shuqi Chen
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics, Nankai University, Tianjin 300071, People's Republic of China
- School of TEDA Institute of Applied Physics, Nankai University, Tianjin 300071, People's Republic of China
- The Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, People's Republic of China
| | - Hui-Tian Wang
- National Laboratory of Solid State Microstructures and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
- The Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, People's Republic of China
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37
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Ghaffari V, Yousefi L. Integrated optical beam steering device using switchable nanoantennas and a reflective metalens. Sci Rep 2023; 13:7099. [PMID: 37130970 PMCID: PMC10154304 DOI: 10.1038/s41598-023-33939-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 04/21/2023] [Indexed: 05/04/2023] Open
Abstract
In this paper, an integrated optical device is proposed in which a reflective meta-lens and five switchable nano-antennas are combined to provide optical beam steering at the standard telecommunication wavelength of 1550 nm. For this purpose, a graphene-based switchable power divider is designed and integrated with nano-antennas to control the flow of the light entering the device. To achieve a higher angular accuracy in the radiated beams, a new algorithm is proposed and utilized to optimize the location of feeding nano-antennas in accordance with the reflective meta-lens. In order to achieve a minimum fluctuation in the light intensity when the beams are rotated in the space, an algorithm is developed to select optimum unit cells for the engineered meta-lens. The whole device is numerically analyzed using Electromagnetic full-wave simulations illustrating an optical beam steering with high accuracy (better than 1 degree) in the beam direction, and a low variation (less than 1 dB) in the radiated light intensity. The proposed integrated device can be used for many applications such as inter- and intra-chip optical interconnects, optical wireless communication systems, and advanced integrated LIDARs.
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Affiliation(s)
- Vahid Ghaffari
- School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, 1417614411, Iran
| | - Leila Yousefi
- School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, 1417614411, Iran.
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38
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Go GH, Park CH, Woo KY, Choi M, Cho YH. Scannable Dual-Focus Metalens with Hybrid Phase. NANO LETTERS 2023; 23:3152-3158. [PMID: 37015348 PMCID: PMC10141419 DOI: 10.1021/acs.nanolett.2c04696] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 03/22/2023] [Indexed: 06/19/2023]
Abstract
Metalenses with two foci in the longitudinal or transverse direction, called bifocal or dual-focus metalenses, are promising building blocks in tomography techniques, data storage, and optical tweezers. For practical applications, relative movement between the beam and specimen is required, and beam scanning is highly desirable for high-speed operation without vibration. However, dual-focus metalenses employ a hyperbolic phase that experiences off-axis aberrations, which is not suitable for beam scanning. Here, we demonstrated a scannable dual-focus metalens by employing a new phase called "hybrid phase". The hybrid phase consists of a hyperbolic phase inside and a quadratic phase outside to reduce off-axis aberrations while maintaining a high numerical aperture. We show that the two foci of the scannable dual-focus metalens move together without severe distortion for incident angles of up to 2.5°. Our design easily extends to the case of multifocusing, which is essential for various applications ranging from imaging to manipulation.
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39
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Fraser W, Ye WN. Silicon Fresnel Zone Plate Metalens with Subwavelength Gratings. SENSORS (BASEL, SWITZERLAND) 2023; 23:4137. [PMID: 37112476 PMCID: PMC10144506 DOI: 10.3390/s23084137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/13/2023] [Accepted: 04/18/2023] [Indexed: 06/19/2023]
Abstract
Metalenses are planar optical components that have demonstrated immense potential for integrated optics. In particular, they are capable of high-efficiency subwavelength focusing without the bulkiness of traditional lenses. Dielectric metalenses operating in the C-band typically employ relatively tall, amorphous silicon structures arranged in a periodic array. Phase control spanning from 0 to 2π is accessed by varying the geometry of these scattering structures. The full 2π phase range is necessary to impose a hyperbolic focusing phase profile, but this is difficult to achieve without custom fabrication practices. In this work, we propose a binary phase Fresnel zone plate metalens designed for the standard 500 nm silicon-on-insulator platform. Our design uses subwavelength gratings with trapezoidal segmentation to form concentric rings. The effective index of the grating is set with the duty cycle using a single full-etch step to form the binary phase profile of the zone plate. The metalens design can be easily tuned to achieve longer focal lengths at different wavelengths. It offers a simple platform for high-throughput wavelength-scale focusing elements in free-space optics, including for microscopy and medical imaging.
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40
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Afridi A, Gieseler J, Meyer N, Quidant R. Ultrathin Tunable Optomechanical Metalens. NANO LETTERS 2023; 23:2496-2501. [PMID: 36951636 PMCID: PMC10103287 DOI: 10.1021/acs.nanolett.2c04105] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 03/15/2023] [Indexed: 06/18/2023]
Abstract
Reconfigurable metasurfaces offer great promises to enhance photonics technology by combining integration with improved functionalities. Recently, reconfigurability in otherwise static metasurfaces has been achieved by modifying the electric permittivity of the meta-atoms themselves or their immediate surrounding. Yet, it remains challenging to achieve significant and fast tunability without increasing bulkiness. Here, we demonstrate an ultrathin tunable metalens whose focal distance can be changed through optomechanical control with moderate continuous wave intensities. We achieve fast focal length changes of more than 5% with response time of the order of 10 μs.
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Affiliation(s)
- Adeel Afridi
- ICFO
Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona, Spain
- Nanophotonic
Systems Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Jan Gieseler
- ICFO
Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona, Spain
| | - Nadine Meyer
- Nanophotonic
Systems Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Romain Quidant
- Nanophotonic
Systems Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
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41
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Liu Y, Liao Q, Wang Y, Li X, Huang L. Ultracompact metalens-based beam-focusing fiber-optic device with a large numerical aperture. OPTICS LETTERS 2023; 48:1742-1745. [PMID: 37221755 DOI: 10.1364/ol.481037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 02/23/2023] [Indexed: 05/25/2023]
Abstract
Conventional optical fibers have good light conduction and transmission properties, and have been widely used in the fields of long-distance fiber-optic communication and sensing. However, due to the dielectric properties of the fiber core and cladding materials, the spot size of the transmitted light is dispersive, which greatly limits the application areas of optical fiber. The emergence of metalenses based on artificial periodic micro-nanostructures is opening the door to a variety of fiber innovations. We demonstrate an ultracompact beam-focusing fiber-optic device based on a composite structure of a single-mode fiber (SMF), a multimode fiber (MMF), and a metalens consisting of periodic micro-nano silicon column structures. Convergent beams with numerical apertures (NAs) of up to 0.64@air and a focal length of 63.6 μm are produced by the metalens on the MMF end face. The metalens-based fiber-optic beam-focusing device could find new applications in optical imaging, particle capture and manipulation, sensing, and fiber lasers.
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42
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de Jong D, Karst J, Ludescher D, Floess M, Moell S, Dirnberger K, Hentschel M, Ludwigs S, Braun PV, Giessen H. Electrically switchable metallic polymer metasurface device with gel polymer electrolyte. NANOPHOTONICS 2023; 12:1397-1404. [PMID: 37114093 PMCID: PMC10125172 DOI: 10.1515/nanoph-2022-0654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 01/08/2023] [Indexed: 06/11/2023]
Abstract
We present an electrically switchable, compact metasurface device based on the metallic polymer PEDOT:PSS in combination with a gel polymer electrolyte. Applying square-wave voltages, we can reversibly switch the PEDOT:PSS from dielectric to metallic. Using this concept, we demonstrate a compact, standalone, and CMOS compatible metadevice. It allows for electrically controlled ON and OFF switching of plasmonic resonances in the 2-3 µm wavelength range, as well as electrically controlled beam switching at angles up to 10°. Furthermore, switching frequencies of up to 10 Hz, with oxidation times as fast as 42 ms and reduction times of 57 ms, are demonstrated. Our work provides the basis towards solid state switchable metasurfaces, ultimately leading to submicrometer-pixel spatial light modulators and hence switchable holographic devices.
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Affiliation(s)
- Derek de Jong
- 4th Physics Institute and Research Center ScoPE, University of Stuttgart, Pfaffenwaldring 57, 70569Stuttgart, Germany
- Department of Materials Science and Engineering, Materials Research Laboratory, and Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, IL61801, USA
| | - Julian Karst
- 4th Physics Institute and Research Center ScoPE, University of Stuttgart, Pfaffenwaldring 57, 70569Stuttgart, Germany
| | - Dominik Ludescher
- 4th Physics Institute and Research Center ScoPE, University of Stuttgart, Pfaffenwaldring 57, 70569Stuttgart, Germany
| | - Moritz Floess
- 4th Physics Institute and Research Center ScoPE, University of Stuttgart, Pfaffenwaldring 57, 70569Stuttgart, Germany
| | - Sophia Moell
- 4th Physics Institute and Research Center ScoPE, University of Stuttgart, Pfaffenwaldring 57, 70569Stuttgart, Germany
| | - Klaus Dirnberger
- IPOC-Functional Polymers, Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569Stuttgart, Germany
| | - Mario Hentschel
- 4th Physics Institute and Research Center ScoPE, University of Stuttgart, Pfaffenwaldring 57, 70569Stuttgart, Germany
| | - Sabine Ludwigs
- IPOC-Functional Polymers, Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569Stuttgart, Germany
| | - Paul V. Braun
- Department of Materials Science and Engineering, Materials Research Laboratory, and Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, IL61801, USA
| | - Harald Giessen
- 4th Physics Institute and Research Center ScoPE, University of Stuttgart, Pfaffenwaldring 57, 70569Stuttgart, Germany
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Chang X, Pivnenko M, Shrestha P, Wu W, Chu D. Increasing steering angle of LCoS in a WSS system through integration with a metasurface. APPLIED OPTICS 2023; 62:D17-D22. [PMID: 37132765 DOI: 10.1364/ao.477902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Liquid crystal on silicon (LCoS) has been the dominant choice for wavelength selective switches (WSSs) in telecommunication industry due to its high spatial resolution and compatibility with software defined flexible grid feature. Current LCoS devices generally have a limited steering angle, which also limits the minimum footprint of the WSS system. The steering angle of LCoS devices is fundamentally determined by the pixel pitch, which is highly challenging to be optimized without resorting to other techniques. In this paper, we present an approach to increase the steering angle of LCoS devices through the integration with dielectric metasurfaces. Here a dielectric Huygens-type metasurface is integrated with an LCoS device to increase its steering angle by 10°. This approach can effectively minimize the overall size of the WSS system while maintaining a small form factor of the LCoS device.
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Fagiani L, Gandolfi M, Carletti L, de Angelis C, Osmond J, Bollani M. Modelling and nanofabrication of chiral dielectric metasurfaces. MICRO AND NANO ENGINEERING 2023. [DOI: 10.1016/j.mne.2023.100187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
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45
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Xia C, Ren Y, Lin P, Wang Y, Xu T. Silicon metasurface-based infrared polarizing beam splitter with on-demand deflection angles. OPTICS LETTERS 2023; 48:1722-1725. [PMID: 37221750 DOI: 10.1364/ol.485709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 02/17/2023] [Indexed: 05/25/2023]
Abstract
Polarizing beam splitters (PBSs) play an important role in applications requiring polarization multiplexing or high polarization purity. Traditional prism-based PBSs usually have large volumes, which hampers their further applications in ultracompact integrated optical systems. Here, we demonstrate a single-layer silicon metasurface-based PBS with the ability to deflect two orthogonally linearly polarized infrared light beams to on-demand angles. The metasurface consists of silicon anisotropic microstructures, which can provide different phase profiles for the two orthogonal polarization states. In experiments, two metasurfaces designed with arbitrary deflection angles for x- and y-polarized light exhibit good splitting performance at an infrared wavelength of 10 μm. We envision that this type of planar and thin PBS can be used in a series of compact thermal infrared systems.
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Jin Z, Lin Y, Wang C, Han Y, Li B, Zhang J, Zhang X, Jia P, Hu Y, Liu Q, Duan H, Korvink JG, Li Y, Jiang H, Deng Y. Topologically optimized concentric-nanoring metalens with 1 mm diameter, 0.8 NA and 600 nm imaging resolution in the visible. OPTICS EXPRESS 2023; 31:10489-10499. [PMID: 37157594 DOI: 10.1364/oe.478680] [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
Metalenses can achieve diffraction-limited focusing via localized phase modification of the incoming light beam. However, the current metalenses face to the restrictions on simultaneously achieving large diameter, large numerical aperture, broad working bandwidth and the structure manufacturability. Herein, we present a kind of metalenses composed of concentric nanorings that can address these restrictions using topology optimization approach. Compared to existing inverse design approaches, the computational cost of our optimization method is greatly reduced for large-size metalenses. With its design flexibility, the achieved metalens can work in the whole visible range with millimeter size and a numerical aperture of 0.8 without involving high-aspect ratio structures and large refractive index materials. Electron-beam resist PMMA with a low refractive index is directly used as the material of the metalens, enabling a much more simplified manufacturing process. Experimental results show that the imaging performance of the fabricated metalens has a resolution better than 600 nm corresponding to the measured FWHM of 745 nm.
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Wang T, Liu D, Xue Z, Wan X. Spectral missing color correction based on an adaptive parameter fitting model. OPTICS EXPRESS 2023; 31:8561-8574. [PMID: 36859968 DOI: 10.1364/oe.480916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 02/03/2023] [Indexed: 06/18/2023]
Abstract
With the development of remote sensing technology, true-color visualization of hyperspectral LiDAR echo signals has become a hotspot for both academic research and commercial applications. The limitation of the emission power of hyperspectral LiDAR causes the loss of spectral-reflectance information in some channels of the hyperspectral LiDAR echo signal. The color reconstructed based on the hyperspectral LiDAR echo signal is bound to have serious color cast problem. To solve the existing problem, a spectral missing color correction approach based on adaptive parameter fitting model is proposed in this study. Given the known missing spectral-reflectance band intervals, the colors in incomplete spectral integration are corrected to accurately restore target colors. Based on the experimental results, the color difference between color blocks and the hyperspectral image corrected by the proposed color correction model is smaller than that of the ground truth, and the image quality is higher, realizing the accurate reproduction of the target color.
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Gong J, Xiong L, Pu M, Guo Y, Wen Y, He Q, Li X, Ma X, Luo X. Simple route for high-throughput fabrication of metasurfaces using one-step UV-curable resin printing. OPTICS EXPRESS 2023; 31:8068-8080. [PMID: 36859924 DOI: 10.1364/oe.481384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 01/20/2023] [Indexed: 06/18/2023]
Abstract
Phase-gradient metasurfaces are two-dimensional (2D) optical elements that can manipulate light by imposing local, space-variant phase changes on an incident electromagnetic wave. These metasurfaces hold the potential and the promise to revolutionize photonics by providing ultrathin alternatives for a wide range of common optical elements such as bulky refractive optics, waveplates, polarizers, and axicons. However, the fabrication of state-of-the-art metasurfaces typically requires some time-consuming, expensive, and possibly hazardous processing steps. To overcome these limitations on conventional metasurface fabrication, a facile methodology to produce phase-gradient metasurfaces through one-step UV-curable resin printing is developed by our research group. The method dramatically reduces the required processing time and cost, as well as eliminates safety hazards. As a proof-of-concept, the advantages of the method are clearly demonstrated via a rapid reproduction of high-performance metalenses based on the Pancharatnam-Berry phase gradient concept in the visible spectrum.
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Dai Y, He T, Wei Z, Wang Z, Cheng X. Anomalous reflection with customized high-efficiency bandwidth. OPTICS LETTERS 2023; 48:956-959. [PMID: 36790984 DOI: 10.1364/ol.480735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 01/09/2023] [Indexed: 06/18/2023]
Abstract
Anomalous reflection from metasurfaces with 100% efficiency at optical frequencies was not achieved until an all-dielectric quasi-three-dimensional subwavelength structure was proposed. The desired nonlocal control of light waves is realized by designing phase responses of multilayer films at a single wavelength. However, a high-efficiency bandwidth is not controllable by designing only the phase response at a single wavelength. Here, we propose the use of a multilayer metasurface to achieve anomalous reflection with a customized high-efficiency bandwidth. The interference of the successive light waves scattered from the structure at multiple wavelengths is controlled by phase dispersion regulation of multilayer films. As a proof of concept, two sets of multilayer films with different phase dispersions were designed to realize broadband (∼110 nm) and narrowband (∼15 nm) anomalous reflections, both with an efficiency of over 80%. The results offer a general strategy to design high-efficiency anomalous reflection with arbitrary bandwidth and might stimulate various potential applications for metadevices.
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Verma S, Rahman B. Computational Investigation of Advanced Refractive Index Sensor Using 3-Dimensional Metamaterial Based Nanoantenna Array. SENSORS (BASEL, SWITZERLAND) 2023; 23:1290. [PMID: 36772328 PMCID: PMC9921925 DOI: 10.3390/s23031290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 01/18/2023] [Accepted: 01/21/2023] [Indexed: 06/18/2023]
Abstract
Photonic researchers are increasingly exploiting nanotechnology due to the development of numerous prevalent nanosized manufacturing technologies, which has enabled novel shape-optimized nanostructures to be manufactured and investigated. Hybrid nanostructures that integrate dielectric resonators with plasmonic nanostructures are also offering new opportunities. In this work, we have explored a hybrid coupled nano-structured antenna with stacked multilayer lithium tantalate (LiTaO3) and Aluminum oxide (Al2O3), operating at wavelength ranging from 400 nm to 2000 nm. Here, the sensitivity response has been explored of these nano-structured hybrid arrays. It shows a strong electromagnetic confinement in the separation gap (g) of the dimers due to strong surface plasmon resonance (SPR). The influences of the structural dimensions have been investigated to optimize the sensitivity. The designed hybrid coupled nanostructure with the combination of 10 layers of gold (Au) and Lithium tantalate (LiTaO3) or Aluminum oxide (Al2O3) (five layers each) having height, h1 = h2 = 10 nm exhibits 730 and 660 nm/RIU sensitivity, respectively. The sensitivity of the proposed hybrid nanostructure has been compared with a single metallic (only gold) elliptical paired nanostructure. Depending on these findings, we demonstrated that a roughly two-fold increase in the sensitivity (S) can be obtained by utilizing a hybrid coupled nanostructure compared to an identical nanostructure, which competes with traditional sensors of the same height, (h). Our innovative novel plasmonic hybrid nanostructures provide a framework for developing plasmonic nanostructures for use in various sensing applications.
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