Chlorotrifluoroethylene(CTFE)is a vital fluorinated olefinic monomer produced through the catalytic hydrodechlorination of trichlorotrifluoroethane(CFC-113),an eco-friendly process.However,hydrodechlorination catalyst...Chlorotrifluoroethylene(CTFE)is a vital fluorinated olefinic monomer produced through the catalytic hydrodechlorination of trichlorotrifluoroethane(CFC-113),an eco-friendly process.However,hydrodechlorination catalysts for olefin production often suffer from poor stability.The Pd/AC catalyst and Pd-Cu/AC catalyst prepared by co-impregnation method exhibited poor stability,Pd-Cu/AC catalyst with CFC-113 conversion dropping to around 37%after 50 h of hydrodechlorination reaction.Brunauer-Emmett-Teller,transmission electron microscopy,X-ray photoelectron spectroscopy,and X-ray diffraction of fresh and deactivated Pd/AC catalysts indicate that the deactivation of Pd/AC catalysts is due to high-temperature agglomeration of Pd.Comparative analysis of fresh and deactivated Pd-Cu/AC catalysts using Brunauer-Emmett-Teller,transmission electron microscopy,and thermogravimetric analysis techniques revealed decreased dispersion of active sites,reduced surface area,catalyst aggregation deactivation,and a significant decrease in Cu content.Furthermore,the results of NH3-TPD revealed that the acid sites of the catalyst increased significantly.X-ray diffraction spectra indicated the formation of new species,basic copper chloride(Cu_(2)(OH)_(3)Cl),during the reaction.As the reaction progressed,these new species agglomerated,leading to a gradual loss of catalyst activity.Moreover,the deactivated catalyst was successfully reactivated using a simple alkaline washing method.展开更多
Advancements in mode-division multiplexing(MDM)techniques,aimed at surpassing the Shannon limit and augmenting transmission capacity,have garnered significant attention in optical fiber communica-tion,propelling the d...Advancements in mode-division multiplexing(MDM)techniques,aimed at surpassing the Shannon limit and augmenting transmission capacity,have garnered significant attention in optical fiber communica-tion,propelling the demand for high-quality multiplexers and demultiplexers.However,the criteria for ideal-mode multiplexers/demultiplexers,such as performance,scalability,compatibility,and ultra-compactness,have only partially been achieved using conventional bulky devices(e.g.,waveguides,grat-ings,and free space optics)—an issue that will substantially restrict the application of MDM techniques.Here,we present a neuro-meta-router(NMR)optimized through deep learning that achieves spatial multi-mode division and supports multi-channel communication,potentially offering scalability,com-patibility,and ultra-compactness.An MDM communication system based on an NMR is theoretically designed and experimentally demonstrated to enable simultaneous and independent multi-dataset transmission,showcasing a capacity of up to 100 gigabits per second(Gbps)and a symbol error rate down to the order of 104,all achieved without any compensation technologies or correlation devices.Our work presents a paradigm that merges metasurfaces,fiber communications,and deep learning,with potential applications in intelligent metasurface-aided optical interconnection,as well as all-optical pat-tern recognition and classification.展开更多
Metasurface-based nanoprinting(meta-nanoprinting)has fully demonstrated its advantages in ultrahigh-density gray-scale/color image recording and display.A typical meta-nanoprinting device usually has image resolutions...Metasurface-based nanoprinting(meta-nanoprinting)has fully demonstrated its advantages in ultrahigh-density gray-scale/color image recording and display.A typical meta-nanoprinting device usually has image resolutions reaching 80 k dots per inch(dpi),far exceeding conventional technology such as gravure printing(typ.5 k dpi).Besides,by fully exploit-ing the design degrees of freedom of nanostructured metasurfaces,meta-nanoprinting has been developed from previ-ous single-channel to multiple-channels,to current multifunctional integration or even dynamic display.In this review,we overview the development of meta-nanoprinting,including the physics of nanoprinting to manipulate optical amplitude and spectrum,single-functional meta-nanoprinting,multichannel meta-nanoprinting,dynamic meta-nanoprinting and mul-tifunctional metasurface integrating nanoprinting with holography or metalens,etc.Applications of meta-nanoprinting such as image display,vortex beam generation,information decoding and hiding,information encryption,high-density optical storage and optical anti-counterfeiting have also been discussed.Finally,we conclude the opportunities and chal-lenges/perspectives in this rapidly developing research field of meta-nanoprinting.展开更多
With the escalating flow of information and digital communication,information security has become an increasingly important issue.Traditional cryptographic methods are being threatened by advancing progress in computi...With the escalating flow of information and digital communication,information security has become an increasingly important issue.Traditional cryptographic methods are being threatened by advancing progress in computing,while physical encryption methods are favored as a viable and compelling avenue.Metasurfaces,which are known for their extraordinary ability to manipulate optical parameters at the nanoscale,exhibit significant potential for the revolution of optical devices,making them a highly promising candidate for optical encryption applications.Here,a single-sized metasurface with four independent channels is proposed for conducting steganography and multi-key information encryption.More specifically,plaintext is transformed into a ciphertext image,which is encoded into a metasurface,while the decryption key is discretely integrated into another channel within the same metasurface.Two different keys for steganographic image unveiling are also encoded into the metasurface and can be retrieved with different channels and spatial positions.This distributed multi-key encryption approach can enhance security,while strategically distributing images across distinct spatial zones serves as an additional measure to reduce the risk of information leakage.This minimalist designed metasurface,with its advantages of high information density and robust security,holds promise across applications including portable encryption,high-camouflaged image display,and high-density optical storage.展开更多
Mode-division multiplexing technology leveraging diverse spatial modes has advanced to sustain capacity expansion in fiber-optic communications.The intelligent recognition of spatial modes using ultra-compact devices ...Mode-division multiplexing technology leveraging diverse spatial modes has advanced to sustain capacity expansion in fiber-optic communications.The intelligent recognition of spatial modes using ultra-compact devices and low-complexity designs is crucial for mode visualization and system miniaturization.In this work,we theoretically design and experimentally demonstrate a neural network-optimized metasurface capable of dual-mode pattern recognition through dual-channel image display.Our framework offers three key advantages:device compatibility,design flexibility,and function scalability by integrating neural networks and metasurfaces into mode-division multiplexing platforms.Our framework enhances research and applications of intelligent metasurface-driven pattern recognition and object classification,as well as information encoding and decoding.展开更多
With the rapid progress in computer science,including artificial intelligence,big data and cloud computing,full-space spot generation can be pivotal to many practical applications,such as facial recognition,motion det...With the rapid progress in computer science,including artificial intelligence,big data and cloud computing,full-space spot generation can be pivotal to many practical applications,such as facial recognition,motion detection,augmented reality,etc.These opportunities may be achieved by using diffractive optical elements(DOEs)or light detection and ranging(LIDAR).However,DOEs suffer from intrinsic limitations,such as demanding depth-controlled fabrication techniques,large thicknesses(more than the wavelength),Lambertian operation only in half space,etc.LIDAR nevertheless relies on complex and bulky scanning systems,which hinders the miniaturization of the spot generator.Here,inspired by a Lambertian scatterer,we report a Hermitian-conjugate metasurface scrambling the incident light to a cloud of random points in full space with compressed information density,functioning in both transmission and reflection spaces.Over 4044 random spots are experimentally observed in the entire space,covering angles at nearly 90°.Our scrambling metasurface is made of amorphous silicon with a uniform subwavelength height,a nearly continuous phase coverage,a lightweight,flexible design,and low-heat dissipation.Thus,it may be mass produced by and integrated into existing semiconductor foundry designs.Our work opens important directions for emerging 3D recognition sensors,such as motion sensing,facial recognition,and other applications.展开更多
Conventional hyperspectral cameras cascade lenses and spectrometers to acquire the spectral datacube,which forms the fundamental framework for hyperspectral imaging.However,this cascading framework involves tradeoffs ...Conventional hyperspectral cameras cascade lenses and spectrometers to acquire the spectral datacube,which forms the fundamental framework for hyperspectral imaging.However,this cascading framework involves tradeoffs among spectral and imaging performances when the system is driven toward miniaturization.Here,we propose a spectral singlet lens that unifies optical imaging and computational spectrometry functions,enabling the creation of minimalist,miniaturized and high-performance hyperspectral cameras.As a paradigm,we capitalize on planar liquid crystal optics to implement the proposed framework,with each liquid-crystal unit cell acting as both phase modulator and electrically tunable spectral filter.Experiments with various targets show that the resulting millimeter-scale hyperspectral camera exhibits both high spectral fidelity(>95%)and high spatial resolutions(~1.7 times the diffraction limit).The proposed“two-in-one”framework can resolve the conflicts between spectral and imaging resolutions,which paves a practical pathway for advancing hyperspectral imaging systems toward miniaturization and portable applications.展开更多
Classified as a non-Hermitian system,topological metasurface is one of the ideal platforms for exploring a striking property,that is,the exceptional point(EP).Recently,creating and encircling EP in metasurfaces has tr...Classified as a non-Hermitian system,topological metasurface is one of the ideal platforms for exploring a striking property,that is,the exceptional point(EP).Recently,creating and encircling EP in metasurfaces has triggered various progressive functionalities,including polarization control and optical holographic encoding.However,existing topological metasurfaces mostly rely on plasmonic materials,which introduce inevitable ohmic losses and limit their compatibility with mainstream all-dielectric meta-devices.Additionally,conventional free-space configurations also hinder the integration of multiple meta-devices in compact platforms.Here,an on-chip topological metasurface is experimentally demonstrated to create and engineer the topological phase encircling the EP in all-dielectric architecture.By massively screening the Si meta-atom geometry on the Si3N4 waveguide,a 2π-topological phase shift is obtained by encircling the EP.Through combining with the Pancharatnam-Berry(PB)phase,we decouple the orthogonal circular polarization channels and unfold the independent encoding freedom for different holographic generations.As a proof of concept,the proposed on-chip topological metasurface enables floating holographic visualizations in real-world scenarios,functioning as practical augmented reality(AR)functionalities.Such the all-dielectric on-chip scheme eliminates ohmic losses and enables compatible integration with other on-chip meta-devices,thus suggesting promising applications in next-generation AR devices,multiplexing information storage,and advanced optical displays.展开更多
Polarization optics plays a pivotal role in diffractive,refractive,and emerging flat optics,and has been widely employed in contemporary optical industries and daily life.Advanced polarization manipulation leads to ro...Polarization optics plays a pivotal role in diffractive,refractive,and emerging flat optics,and has been widely employed in contemporary optical industries and daily life.Advanced polarization manipulation leads to robust control of the polarization direction of light.Nevertheless,polarization control has been studied largely independent of the phase or intensity of light.Here,we propose and experimentally validate a Malus-metasurface-assisted paradigm to enable simultaneous and independent control of the intensity and phase properties of light simply by polarization modulation.The orientation degeneracy of the classical Malus’s law implies a new degree of freedom and enables us to establish a one-to-many mapping strategy for designing anisotropic plasmonic nanostructures to engineer the Pancharatnam–Berry phase profile,while keeping the continuous intensity modulation unchanged.The proposed Malus metadevice can thus generate a near-field greyscale pattern,and project an independent far-field holographic image using an ultrathin and single-sized metasurface.This concept opens up distinct dimensions for conventional polarization optics,which allows one to merge the functionality of phase manipulation into an amplitudemanipulation-assisted optical component to form a multifunctional nano-optical device without increasing the complexity of the nanostructures.It can empower advanced applications in information multiplexing and encryption,anti-counterfeiting,dual-channel display for virtual/augmented reality,and many other related fields.展开更多
The design of a conventional zoom lens is always challenging because it requires not only sophisticated optical design strategy, but also complex and precise mechanical structures for system adjustment. Here, we propo...The design of a conventional zoom lens is always challenging because it requires not only sophisticated optical design strategy, but also complex and precise mechanical structures for system adjustment. Here, we propose a continuous-zoom lens consisting of two chiral geometric metasurfaces with dielectric nanobrick arrays sitting on a transparent substrate. The metalens can continuously vary the focal length by rotating either of the two metasurfaces around its optical axis without changing any other conditions. Due to the polarization dependence of the geometric metasurface, the positive and negative polarities are interchangeable in one identical metalens only by changing the handedness of the incident circularly polarized light, which can generate varying focal lengths ranging from-∞ to +∞ in principle.展开更多
The unwanted zero-order light accompanied by the birth of diffractive optical elements and caused mainly by fabrication errors and wavelength variations is a key factor that deteriorates the performance of diffraction...The unwanted zero-order light accompanied by the birth of diffractive optical elements and caused mainly by fabrication errors and wavelength variations is a key factor that deteriorates the performance of diffraction-related optical devices such as holograms,gratings,beam shapers,beam splitters,optical diffusers,and diffractive microlenses.Here,inspired by the unique characteristic of nano-polarizer-based metasurfaces for both positive and negative amplitude modulation of incident light,we propose a general design paradigm to eliminate zero-order diffraction without burdening the metasurface design and fabrication.The experimentally demonstrated metahologram,which projects a holographic image with a wide angle of 70°×70°in the for field,presents a very low zero-order intensity(only 0.7%of the total energy of the reconstructed image).More importantly,the zero-orderfree meta-hologram has a large tolerance limit for wavelength variations(under a broadband illumination from520 to 660 nm),which brings important technical advances.The strategy proposed could significantly relieve the fabrication difficulty of metasurfaces and be viable for various diffractive-optics-related applications includingholography,laser beam shaping,optical data storage,vortex beam generation,and so on.展开更多
Highly efficient multi-dimensional data storage and extraction are two primary ends for the design and fabrication of emerging optical materials.Although metasurfaces show great potential in information storage due to...Highly efficient multi-dimensional data storage and extraction are two primary ends for the design and fabrication of emerging optical materials.Although metasurfaces show great potential in information storage due to their modulation for different degrees of freedom of light,a compact and efficient detector for relevant multi-dimensional data retrieval is still a challenge,especially in complex environments.Here,we demonstrate a multi-dimensional image storage and retrieval process by using a dual-color metasurface and a double-layer integrated perovskite single-pixel detector(DIP-SPD).Benefitting from the photoelectric response characteristics of the FAPbBr2.4l0.6 and FAPbl3 films and their stacked structure,our filter-free DIP-SPD can accurately reconstruct different colorful images stored in a metasurface within a single-round measurement,even in complex environments with scattering media or strong background noise.Our work not only provides a compact,filter-free,and noise-robust detector for colorful image extraction in a metasurface,but also paves the way for color imaging application of perovskite-like bandgap tunable materials.展开更多
For a conventional cascaded metasurface,the combination channel and each single channel are mutually dependent because the phase modulation of a cascaded metasurface is the sum of each single one.Here we propose a cas...For a conventional cascaded metasurface,the combination channel and each single channel are mutually dependent because the phase modulation of a cascaded metasurface is the sum of each single one.Here we propose a cascaded metasurface that can independently encode information into multiple channels.Based on the orientation degeneracy of anisotropic metasurfaces,each single metasurface can produce a quick-response(QR)image in the near field,governed by the Malus law,while the combined channel can produce a holographic image in the far field,governed by geometric phase.The independent and physically separated trichannel design makes information encryption safer.展开更多
Vortex light is a unique beam characterized by a spiral phase as it propagates. A fundamental parameter of vortex light is the topological charge, which determines the amount of angular momentum and plays a crucial ro...Vortex light is a unique beam characterized by a spiral phase as it propagates. A fundamental parameter of vortex light is the topological charge, which determines the amount of angular momentum and plays a crucial role in tailoring its behavior. However, conventional measurement methods for determining the topological charge, such as those based on interference and phase modulation, tend to be intricate and complex. In this regard, a labeled vortex beam generator is proposed, composed of a metasurface with a single-celled configuration. When the metasurface is illuminated by light of the designed wavelength, the outgoing light exhibits a vortex structure. Furthermore, the topological charge numbers can be directly observed with distinct labeled patterns when the metasurface is placed in an orthogonal-polarized optical path. With advantages such as ultra-compactness, high robustness, and exceptional precision, the proposed metasurface exhibits significant potential for applications in optical communication, light manipulation, optical sensing, etc.展开更多
基金supported by the National Natural Science Foundation of China(22008212,22078292,21902124)Natural Science Basic Research Planning Shaanxi Province of China(2017ZDJC-29)+2 种基金Key Research and Development Project of Shaanxi Province(2018ZDXM-GY-173)China Postdoctoral Science Foundation(2019 M663848)Open cooperative innovation fund of Xi'an Institute of modern chemistry(SYJJ48).
文摘Chlorotrifluoroethylene(CTFE)is a vital fluorinated olefinic monomer produced through the catalytic hydrodechlorination of trichlorotrifluoroethane(CFC-113),an eco-friendly process.However,hydrodechlorination catalysts for olefin production often suffer from poor stability.The Pd/AC catalyst and Pd-Cu/AC catalyst prepared by co-impregnation method exhibited poor stability,Pd-Cu/AC catalyst with CFC-113 conversion dropping to around 37%after 50 h of hydrodechlorination reaction.Brunauer-Emmett-Teller,transmission electron microscopy,X-ray photoelectron spectroscopy,and X-ray diffraction of fresh and deactivated Pd/AC catalysts indicate that the deactivation of Pd/AC catalysts is due to high-temperature agglomeration of Pd.Comparative analysis of fresh and deactivated Pd-Cu/AC catalysts using Brunauer-Emmett-Teller,transmission electron microscopy,and thermogravimetric analysis techniques revealed decreased dispersion of active sites,reduced surface area,catalyst aggregation deactivation,and a significant decrease in Cu content.Furthermore,the results of NH3-TPD revealed that the acid sites of the catalyst increased significantly.X-ray diffraction spectra indicated the formation of new species,basic copper chloride(Cu_(2)(OH)_(3)Cl),during the reaction.As the reaction progressed,these new species agglomerated,leading to a gradual loss of catalyst activity.Moreover,the deactivated catalyst was successfully reactivated using a simple alkaline washing method.
基金supported by the National Key Research and Development Program of China(2023YFB2804704)the National Natural Science Foundation of China(12174292,12374278,and 62105250).
文摘Advancements in mode-division multiplexing(MDM)techniques,aimed at surpassing the Shannon limit and augmenting transmission capacity,have garnered significant attention in optical fiber communica-tion,propelling the demand for high-quality multiplexers and demultiplexers.However,the criteria for ideal-mode multiplexers/demultiplexers,such as performance,scalability,compatibility,and ultra-compactness,have only partially been achieved using conventional bulky devices(e.g.,waveguides,grat-ings,and free space optics)—an issue that will substantially restrict the application of MDM techniques.Here,we present a neuro-meta-router(NMR)optimized through deep learning that achieves spatial multi-mode division and supports multi-channel communication,potentially offering scalability,com-patibility,and ultra-compactness.An MDM communication system based on an NMR is theoretically designed and experimentally demonstrated to enable simultaneous and independent multi-dataset transmission,showcasing a capacity of up to 100 gigabits per second(Gbps)and a symbol error rate down to the order of 104,all achieved without any compensation technologies or correlation devices.Our work presents a paradigm that merges metasurfaces,fiber communications,and deep learning,with potential applications in intelligent metasurface-aided optical interconnection,as well as all-optical pat-tern recognition and classification.
基金We are grateful for financial supports from the National Key Research and Development Program of China(Grant No.2021YFE0205800)National Natural Science Foundation of China(Grant Nos.12174292,62205252,11904267 and 91950110)the Fundamental Research Funds for the Central Universities(Grant Nos.2042022kf0024,2042022kf1013 and 2042022kf1011).
文摘Metasurface-based nanoprinting(meta-nanoprinting)has fully demonstrated its advantages in ultrahigh-density gray-scale/color image recording and display.A typical meta-nanoprinting device usually has image resolutions reaching 80 k dots per inch(dpi),far exceeding conventional technology such as gravure printing(typ.5 k dpi).Besides,by fully exploit-ing the design degrees of freedom of nanostructured metasurfaces,meta-nanoprinting has been developed from previ-ous single-channel to multiple-channels,to current multifunctional integration or even dynamic display.In this review,we overview the development of meta-nanoprinting,including the physics of nanoprinting to manipulate optical amplitude and spectrum,single-functional meta-nanoprinting,multichannel meta-nanoprinting,dynamic meta-nanoprinting and mul-tifunctional metasurface integrating nanoprinting with holography or metalens,etc.Applications of meta-nanoprinting such as image display,vortex beam generation,information decoding and hiding,information encryption,high-density optical storage and optical anti-counterfeiting have also been discussed.Finally,we conclude the opportunities and chal-lenges/perspectives in this rapidly developing research field of meta-nanoprinting.
基金supported by the National Natural Science Foundation of China(12204359 and 12174292)the China Postdoctoral Science Foundation(2022TQ0243 and 2022M722448)+1 种基金the Natural Science Foundation of Hubei Province(2022CFB641)the Natural Science Foundation of Jiangsu Province(BK20231210).
文摘With the escalating flow of information and digital communication,information security has become an increasingly important issue.Traditional cryptographic methods are being threatened by advancing progress in computing,while physical encryption methods are favored as a viable and compelling avenue.Metasurfaces,which are known for their extraordinary ability to manipulate optical parameters at the nanoscale,exhibit significant potential for the revolution of optical devices,making them a highly promising candidate for optical encryption applications.Here,a single-sized metasurface with four independent channels is proposed for conducting steganography and multi-key information encryption.More specifically,plaintext is transformed into a ciphertext image,which is encoded into a metasurface,while the decryption key is discretely integrated into another channel within the same metasurface.Two different keys for steganographic image unveiling are also encoded into the metasurface and can be retrieved with different channels and spatial positions.This distributed multi-key encryption approach can enhance security,while strategically distributing images across distinct spatial zones serves as an additional measure to reduce the risk of information leakage.This minimalist designed metasurface,with its advantages of high information density and robust security,holds promise across applications including portable encryption,high-camouflaged image display,and high-density optical storage.
基金supported by the National Key Research and Development Program of China(No.2023YFB2804704)the National Natural Science Foundation of China(Nos.12374278 and 12174292)the Outstanding Youth Funds of Hubei Province(No.2025AFA090)。
文摘Mode-division multiplexing technology leveraging diverse spatial modes has advanced to sustain capacity expansion in fiber-optic communications.The intelligent recognition of spatial modes using ultra-compact devices and low-complexity designs is crucial for mode visualization and system miniaturization.In this work,we theoretically design and experimentally demonstrate a neural network-optimized metasurface capable of dual-mode pattern recognition through dual-channel image display.Our framework offers three key advantages:device compatibility,design flexibility,and function scalability by integrating neural networks and metasurfaces into mode-division multiplexing platforms.Our framework enhances research and applications of intelligent metasurface-driven pattern recognition and object classification,as well as information encoding and decoding.
基金supports from the National Natural Science Foundation of China(Numbers 11574240 and 11774273)the Outstanding Youth Funds of Hubei Province(Number 2016CFA034)+4 种基金the Open Foundation of State Key Laboratory of Optical Communication Technologies and Networks,Wuhan Research Institute of Posts and Telecommunications(Number OCTN-201605)the financial supports from the Postdoctoral Innovation Talent Support Program of China(BX20180221)the Global Ph.D.fellowship from the Korean government(NRF-2016H1A2A1906519)the financial support from the National Research Foundation(NRF)grants(NRF-2017R1E1A1A03070501,NRF-2017R1E1A2A01076613,NRF-2018M3D1A1058998,NRF-2015R1A5A1037668,and CAMM-2014M3A6B3063708)funded by the Ministry of Science and ICT(MSIT)of the Korean governmentthe financial support from the National Research Foundation,Prime Minister’s Office,Singapore under its Competitive Research Program(CRP award NRF CRP15-2015-03).
文摘With the rapid progress in computer science,including artificial intelligence,big data and cloud computing,full-space spot generation can be pivotal to many practical applications,such as facial recognition,motion detection,augmented reality,etc.These opportunities may be achieved by using diffractive optical elements(DOEs)or light detection and ranging(LIDAR).However,DOEs suffer from intrinsic limitations,such as demanding depth-controlled fabrication techniques,large thicknesses(more than the wavelength),Lambertian operation only in half space,etc.LIDAR nevertheless relies on complex and bulky scanning systems,which hinders the miniaturization of the spot generator.Here,inspired by a Lambertian scatterer,we report a Hermitian-conjugate metasurface scrambling the incident light to a cloud of random points in full space with compressed information density,functioning in both transmission and reflection spaces.Over 4044 random spots are experimentally observed in the entire space,covering angles at nearly 90°.Our scrambling metasurface is made of amorphous silicon with a uniform subwavelength height,a nearly continuous phase coverage,a lightweight,flexible design,and low-heat dissipation.Thus,it may be mass produced by and integrated into existing semiconductor foundry designs.Our work opens important directions for emerging 3D recognition sensors,such as motion sensing,facial recognition,and other applications.
基金supported by the National Key Research and Development Program of China(Grant Nos.2023YFB2804700,2021YFA1202000 and 2021YFE0205800)National Natural Science Foundation of China(Grant Nos.12174292,62222507,and 62175101)+1 种基金Natural Science Foundation of Jiangsu Province(No.BK20212004)Fundamental Research Funds for the Central Universities(2042024kf1005).
文摘Conventional hyperspectral cameras cascade lenses and spectrometers to acquire the spectral datacube,which forms the fundamental framework for hyperspectral imaging.However,this cascading framework involves tradeoffs among spectral and imaging performances when the system is driven toward miniaturization.Here,we propose a spectral singlet lens that unifies optical imaging and computational spectrometry functions,enabling the creation of minimalist,miniaturized and high-performance hyperspectral cameras.As a paradigm,we capitalize on planar liquid crystal optics to implement the proposed framework,with each liquid-crystal unit cell acting as both phase modulator and electrically tunable spectral filter.Experiments with various targets show that the resulting millimeter-scale hyperspectral camera exhibits both high spectral fidelity(>95%)and high spatial resolutions(~1.7 times the diffraction limit).The proposed“two-in-one”framework can resolve the conflicts between spectral and imaging resolutions,which paves a practical pathway for advancing hyperspectral imaging systems toward miniaturization and portable applications.
基金the National Key Research and Development Program of China(No.2022YFB3808600)the National Natural Science Foundation of China(No.12474391)+3 种基金the Fundamental Research Funds for the Central Universities(2042025kf0024)support from the National Natural Science Foundation of China(12474388)Guangdong Basic and Applied Basic Research Foundation(2025A1515011483)supported by the Center for NanoScience and Nanotechnology at Wuhan University.
文摘Classified as a non-Hermitian system,topological metasurface is one of the ideal platforms for exploring a striking property,that is,the exceptional point(EP).Recently,creating and encircling EP in metasurfaces has triggered various progressive functionalities,including polarization control and optical holographic encoding.However,existing topological metasurfaces mostly rely on plasmonic materials,which introduce inevitable ohmic losses and limit their compatibility with mainstream all-dielectric meta-devices.Additionally,conventional free-space configurations also hinder the integration of multiple meta-devices in compact platforms.Here,an on-chip topological metasurface is experimentally demonstrated to create and engineer the topological phase encircling the EP in all-dielectric architecture.By massively screening the Si meta-atom geometry on the Si3N4 waveguide,a 2π-topological phase shift is obtained by encircling the EP.Through combining with the Pancharatnam-Berry(PB)phase,we decouple the orthogonal circular polarization channels and unfold the independent encoding freedom for different holographic generations.As a proof of concept,the proposed on-chip topological metasurface enables floating holographic visualizations in real-world scenarios,functioning as practical augmented reality(AR)functionalities.Such the all-dielectric on-chip scheme eliminates ohmic losses and enables compatible integration with other on-chip meta-devices,thus suggesting promising applications in next-generation AR devices,multiplexing information storage,and advanced optical displays.
基金the support from the MOST 2017YFA0205800the funding provided by the National Natural Science Foundation of China(Nos.91950110,11774273,11904267,61805184,and 11674256)+2 种基金the financial support from the Postdoctoral Innovation Talent Support Program of China(BX20180221)the China Postdoctoral Science Foundation(2019M652688)the financial support from the National Research Foundation,Prime Minister’s Office,Singapore under its Competitive Research Program(CRP award NRF CRP15-2015-03).
文摘Polarization optics plays a pivotal role in diffractive,refractive,and emerging flat optics,and has been widely employed in contemporary optical industries and daily life.Advanced polarization manipulation leads to robust control of the polarization direction of light.Nevertheless,polarization control has been studied largely independent of the phase or intensity of light.Here,we propose and experimentally validate a Malus-metasurface-assisted paradigm to enable simultaneous and independent control of the intensity and phase properties of light simply by polarization modulation.The orientation degeneracy of the classical Malus’s law implies a new degree of freedom and enables us to establish a one-to-many mapping strategy for designing anisotropic plasmonic nanostructures to engineer the Pancharatnam–Berry phase profile,while keeping the continuous intensity modulation unchanged.The proposed Malus metadevice can thus generate a near-field greyscale pattern,and project an independent far-field holographic image using an ultrathin and single-sized metasurface.This concept opens up distinct dimensions for conventional polarization optics,which allows one to merge the functionality of phase manipulation into an amplitudemanipulation-assisted optical component to form a multifunctional nano-optical device without increasing the complexity of the nanostructures.It can empower advanced applications in information multiplexing and encryption,anti-counterfeiting,dual-channel display for virtual/augmented reality,and many other related fields.
基金supported by the National Natural Science Foundation of China(Nos.11774273,11574240,61640409,and 61805184)the Outstanding Youth Funds of Hubei Province(No.2016CFA034)+2 种基金the Open Foundation of State Key Laboratory of Optical Communication Technologies and Networks,Wuhan Research Institute of Posts and Telecommunications(No.OCTN-201605)the Postdoctoral Innovation Talent Support Program of China(No.BX20180221)the Natural Science Foundation of Guangxi(No.2017GXNSFAA198048)
文摘The design of a conventional zoom lens is always challenging because it requires not only sophisticated optical design strategy, but also complex and precise mechanical structures for system adjustment. Here, we propose a continuous-zoom lens consisting of two chiral geometric metasurfaces with dielectric nanobrick arrays sitting on a transparent substrate. The metalens can continuously vary the focal length by rotating either of the two metasurfaces around its optical axis without changing any other conditions. Due to the polarization dependence of the geometric metasurface, the positive and negative polarities are interchangeable in one identical metalens only by changing the handedness of the incident circularly polarized light, which can generate varying focal lengths ranging from-∞ to +∞ in principle.
基金National Key Research and Development Program of China(2017YFA0205800)National Natural Science Foundation of China(91950110,11774273,11904267,61805184,11674256)+2 种基金Outstanding Youth Funds of Hubei Province(2016CFA034)Postdoctoral Innovation Talent Support Program of China(BX20180221)China Postdoctoral Science Foundation(2019M652688)。
文摘The unwanted zero-order light accompanied by the birth of diffractive optical elements and caused mainly by fabrication errors and wavelength variations is a key factor that deteriorates the performance of diffraction-related optical devices such as holograms,gratings,beam shapers,beam splitters,optical diffusers,and diffractive microlenses.Here,inspired by the unique characteristic of nano-polarizer-based metasurfaces for both positive and negative amplitude modulation of incident light,we propose a general design paradigm to eliminate zero-order diffraction without burdening the metasurface design and fabrication.The experimentally demonstrated metahologram,which projects a holographic image with a wide angle of 70°×70°in the for field,presents a very low zero-order intensity(only 0.7%of the total energy of the reconstructed image).More importantly,the zero-orderfree meta-hologram has a large tolerance limit for wavelength variations(under a broadband illumination from520 to 660 nm),which brings important technical advances.The strategy proposed could significantly relieve the fabrication difficulty of metasurfaces and be viable for various diffractive-optics-related applications includingholography,laser beam shaping,optical data storage,vortex beam generation,and so on.
基金support from the Science and Technology Development Fund,Macao SAR(file nos.0071/2019/AMJ,0125/2018/A3,0062/2020/AMJ,and 0038/2019/A1)the Multi-year Research Grants(MYRG2020-00082-IAPME,MYRG2020-00207-IAPME)from the University of Macao+1 种基金National Key Research and Development Program of China(No.2021YFE0205800)National Natural Science Foundation of China(Nos.12174292 and 12374278)。
文摘Highly efficient multi-dimensional data storage and extraction are two primary ends for the design and fabrication of emerging optical materials.Although metasurfaces show great potential in information storage due to their modulation for different degrees of freedom of light,a compact and efficient detector for relevant multi-dimensional data retrieval is still a challenge,especially in complex environments.Here,we demonstrate a multi-dimensional image storage and retrieval process by using a dual-color metasurface and a double-layer integrated perovskite single-pixel detector(DIP-SPD).Benefitting from the photoelectric response characteristics of the FAPbBr2.4l0.6 and FAPbl3 films and their stacked structure,our filter-free DIP-SPD can accurately reconstruct different colorful images stored in a metasurface within a single-round measurement,even in complex environments with scattering media or strong background noise.Our work not only provides a compact,filter-free,and noise-robust detector for colorful image extraction in a metasurface,but also paves the way for color imaging application of perovskite-like bandgap tunable materials.
基金supported by the National Key Research and Development Program of China(No.2021YFE0205800)the National Natural Science Foundation of China(Nos.12174292,11904267,and 91950110)the Fundamental Research Funds for the Central Universities(Nos.2042022kf1013,2042022kf0024,and 2042021kf0018)。
文摘For a conventional cascaded metasurface,the combination channel and each single channel are mutually dependent because the phase modulation of a cascaded metasurface is the sum of each single one.Here we propose a cascaded metasurface that can independently encode information into multiple channels.Based on the orientation degeneracy of anisotropic metasurfaces,each single metasurface can produce a quick-response(QR)image in the near field,governed by the Malus law,while the combined channel can produce a holographic image in the far field,governed by geometric phase.The independent and physically separated trichannel design makes information encryption safer.
基金This study is supported by National Key Research and Development Program of China(2021YFE0205800)National Natural Science Foundation of China(12204359,62205252)+2 种基金China Postdoctoral Science Foundation(2022TQ0243,2022M722448)the Fundamental Research Funds for the Central Universities(2042022kf1013)Natural Science Foundation of Hubei Province(2022CFB641).
文摘Vortex light is a unique beam characterized by a spiral phase as it propagates. A fundamental parameter of vortex light is the topological charge, which determines the amount of angular momentum and plays a crucial role in tailoring its behavior. However, conventional measurement methods for determining the topological charge, such as those based on interference and phase modulation, tend to be intricate and complex. In this regard, a labeled vortex beam generator is proposed, composed of a metasurface with a single-celled configuration. When the metasurface is illuminated by light of the designed wavelength, the outgoing light exhibits a vortex structure. Furthermore, the topological charge numbers can be directly observed with distinct labeled patterns when the metasurface is placed in an orthogonal-polarized optical path. With advantages such as ultra-compactness, high robustness, and exceptional precision, the proposed metasurface exhibits significant potential for applications in optical communication, light manipulation, optical sensing, etc.
