Let there be light-to change the world we want to be!Over the past several decades,and ever since the birth of the first laser,mankind has witnessed the development of the science of light,as light-based technologies ...Let there be light-to change the world we want to be!Over the past several decades,and ever since the birth of the first laser,mankind has witnessed the development of the science of light,as light-based technologies have revolutionarily changed our lives.Needless to say,photonics has now penetrated into many aspects of science and technology,turning into an important and dynamically changing field of increasing interdisciplinary interest.In this inaugural issue of eLight,we highlight a few emerging trends in photonics that we think are likely to have major impact at least in the upcoming decade,spanning from integrated quantum photonics and quantum computing,through topological/non-Hermitian photonics and topological insulator lasers,to AI-empowered nanophotonics and photonic machine learning.This Perspective is by no means an attempt to summarize all the latest advances in photonics,yet we wish our subjective vision could fuel inspiration and foster excitement in scientific research especially for young researchers who love the science of light.展开更多
The use of optical tweezers to measure forces acting upon microscopic particles has revolutionised fields from material science to cell biology.However,despite optical control capabilities,this technology is highly co...The use of optical tweezers to measure forces acting upon microscopic particles has revolutionised fields from material science to cell biology.However,despite optical control capabilities,this technology is highly constrained by the material properties of the probe,and its use may be limited due to concerns about the effect on biological processes.Here we present a novel,optically controlled trapping method based on light-induced hydrodynamic flows.Specifically,we leverage optical control capabilities to convert a translationally invariant topological defect of a flow field into an attractor for colloids in an effectively one-dimensional harmonic,yet freely rotatable system.Circumventing the need to stabilise particle dynamics along an unstable axis,this novel trap closely resembles the isotropic dynamics of optical tweezers.Using magnetic beads,we explicitly show the existence of a linear force-extension relationship that can be used to detect femtoNewton-range forces with sensitivity close to the thermal limit.Our force measurements remove the need for laser-particle contact,while also lifting material constraints,which renders them a particu-larly interesting tool for the life sciences and engineering.展开更多
Although small EVs(sEVs)have been used widely as biomarkers in disease diagnosis,their heterogeneity at single EV level has rarely been revealed.This is because high-resolution characterization of sEV presents a major...Although small EVs(sEVs)have been used widely as biomarkers in disease diagnosis,their heterogeneity at single EV level has rarely been revealed.This is because high-resolution characterization of sEV presents a major challenge,as their sizes are below the optical diffraction limit.Here,we report that upconversion nanoparticles(UCNPs)can be used for super-resolution profiling the molecular heterogeneity of sEVs.We show that Er3+-doped UCNPs has better brightness and Tm3+-doped UCNPs resulting in better resolution beyond diffraction limit.Through an orthogonal experimental design,the specific targeting of UCNPs to the tumour epitope on single EV has been cross validated,resulting in the Pearson’s R-value of 0.83 for large EVs and~65%co-localization double-positive spots for sEVs.Furthermore,super-resolution nanoscopy can distinguish adjacent UCNPs on single sEV with a resolution of as high as 41.9 nm.When decreasing the size of UCNPs from 40 to 27 nm and 18 nm,we observed that the maximum UCNPs number on single sEV increased from 3 to 9 and 21,respectively.This work suggests the great potentials of UCNPs approach“digitally”quantify the surface antigens on single EVs,therefore providing a solution to monitor the EV heterogeneity changes along with the tumour progression progress.展开更多
Modern optical imaging techniques provide powerful tools for observing cortical structure and functions at high resolutions.Various skull windows have been established for different applications of cortical imaging,an...Modern optical imaging techniques provide powerful tools for observing cortical structure and functions at high resolutions.Various skull windows have been established for different applications of cortical imaging,and each has its advantages and limitations.Most critical of the limitations,none of the current skull windows is suitable for observing the responses to some acute craniocerebral injuries on a large scale and at high resolution.Here,we developed a“Through-Intact-Skull(TIS)window”that enables the observation of an immune response on a bilateral cortical scale and at single-cell resolution after traumatic brain injury without affecting the pathological environment of the brain.The TIS window also has the advantages of craniotomy-freeness,centimeter-field of view,synaptic resolution,large imaging depth,long-term observation capability,and suitability for awake mice.Therefore,the TIS window is a promising new approach for intravital cortical microscopy in basic research in neuroscience.展开更多
High-throughput computational imaging requires efficient processing algorithms to retrieve multi-dimensional and multi-scale information.In computational phase imaging,phase retrieval(PR)is required to reconstruct bot...High-throughput computational imaging requires efficient processing algorithms to retrieve multi-dimensional and multi-scale information.In computational phase imaging,phase retrieval(PR)is required to reconstruct both amplitude and phase in complex space from intensity-only measurements.The existing PR algorithms suffer from the tradeoff among low computational complexity,robustness to measurement noise and strong generalization on different modalities.In this work,we report an efficient large-scale phase retrieval technique termed as LPR.It extends the plug-and-play generalized-alternating-projection framework from real space to nonlinear complex space.The alternating projection solver and enhancing neural network are respectively derived to tackle the measurement formation and statistical prior regularization.This framework compensates the shortcomings of each operator,so as to realize high-fidelity phase retrieval with low computational complexity and strong generalization.We applied the technique for a series of computational phase imaging modalities including coherent diffraction imaging,coded diffraction pattern imaging,and Fourier ptychographic microscopy.Extensive simulations and experiments validate that the technique outperforms the existing PR algorithms with as much as 17dB enhancement on signal-to-noise ratio,and more than one order-of-magnitude increased running efficiency.Besides,we for the first time demonstrate ultralarge-scale phase retrieval at the 8K level(7680×4320 pixels)in minute-level time.展开更多
Water plays a vital role in biological metabolism and it would be essential to trace the water content non-invasively,such as leveraging the vibrational absorption peak of the O-H bond.However,due to the lack of an ef...Water plays a vital role in biological metabolism and it would be essential to trace the water content non-invasively,such as leveraging the vibrational absorption peak of the O-H bond.However,due to the lack of an efficient laser source,it was challenging to image the water content in the deep tissue with micron-level spatial resolution.To address this problem,we develop a high-power hybrid optical parametrically-oscillating emitter(HOPE)at 1930 nm,at which the vibrational absorption peak of the O-H bond locates.The maximum pulse energy is over 1.74μJ with a pulse repetition rate of 50 kHz and a pulse width of 15 ns.We employ this laser source in the optical-resolution photoacoustic microscopy(OR-PAM)system to image the water content in the phantom and the biological tissue in vitro.Our 1930-nm OR-PAM could map the water content in the complex tissue environment at high spatial resolution,deep penetration depth,improved sensitivity,and suppressed artifact signal of the lipid.展开更多
Whispering-gallery-mode(WGM)cavity is important for exploring physics of strong light-matter interaction.Yet it suffers from the notorious radiation loss universally due to the light tunneling effect through the curve...Whispering-gallery-mode(WGM)cavity is important for exploring physics of strong light-matter interaction.Yet it suffers from the notorious radiation loss universally due to the light tunneling effect through the curved boundary.In this work,we propose and demonstrate an optical black hole(OBH)cavity based on transformation optics.The radiation loss of all WGMs in the ideal OBH cavity is completely inhibited by an infinite wide potential barrier.Besides,the WGM field in the OBH cladding is revealed to follow 1/r decay rule based on conformal mapping,which is fundamentally different from the conventional Hankel-function distributions in a homogeneous cavity.Experimentally,a truncated OBH cavity is achieved based on the effective medium theory,and both the Q-factor enhancement and tightly confined WGM fields are measured in the microwave spectra which agree well with the theoretical results.The circular OBH cavity is further applied to the arbitrary-shaped cavities including single-core and multi-core structures with high-Q factor via the conformal mapping.The OBH cavity design strategy can be generalized to resonant modes of various wave systems,such as acoustic and elastic waves,and finds applications in energy harvesting and optoelectronics.展开更多
Planar and ultrathin liquid crystal(LC)polarization optical elements have found promising applications in augmented reality(AR),virtual reality(VR),and photonic devices.In this paper,we give a comprehensive review on ...Planar and ultrathin liquid crystal(LC)polarization optical elements have found promising applications in augmented reality(AR),virtual reality(VR),and photonic devices.In this paper,we give a comprehensive review on the operation principles,device fabrication,and performance of these optical elements.Optical simulations methods for optimizing the device performance are discussed in detail.Finally,some potential applications of these devices in AR and VR systems are illustrated and analyzed.展开更多
Neutron-transmutation doping(NTD)has been demonstrated for the first time in this work for substitutional introduction of tin(Sn)shallow donors into two-dimensional(2D)layered indium selenide(InSe)to manipulate electr...Neutron-transmutation doping(NTD)has been demonstrated for the first time in this work for substitutional introduction of tin(Sn)shallow donors into two-dimensional(2D)layered indium selenide(InSe)to manipulate electron transfer and charge carrier dynamics.Multidisciplinary study including density functional theory,transient optical absorption,and FET devices have been carried out to reveal that the field effect electron mobility of the fabricated phototransistor is increased 100-fold due to the smaller electron effective mass and longer electron life time in the Sn-doped InSe.The responsivity of the Sn-doped InSe based phototransistor is accordingly enhanced by about 50 times,being as high as 397 A/W.The results show that NTD is a highly effective and controllable doping method,possessing good compatibility with the semiconductor manufacturing process,even after device fabrication,and can be carried out without introducing any contamination,which is radically different from traditional doping methods.展开更多
Privacy protection is a growing concern in the digital era,with machine vision techniques widely used throughout public and private settings.Existing methods address this growing problem by,e.g.,encrypting camera imag...Privacy protection is a growing concern in the digital era,with machine vision techniques widely used throughout public and private settings.Existing methods address this growing problem by,e.g.,encrypting camera images or obscuring/blurring the imaged information through digital algorithms.Here,we demonstrate a camera design that performs class-specific imaging of target objects with instantaneous all-optical erasure of other classes of objects.This diffractive camera consists of transmissive surfaces structured using deep learning to perform selective imaging of target classes of objects positioned at its input field-of-view.After their fabrication,the thin diffractive layers collectively perform optical mode filtering to accurately form images of the objects that belong to a target data class or group of classes,while instantaneously erasing objects of the other data classes at the output field-of-view.Using the same framework,we also demonstrate the design of class-specific permutation and class-specific linear transformation cameras,where the objects of a target data class are pixel-wise permuted or linearly transformed following an arbitrarily selected transformation matrix for all-optical class-specific encryption,while the other classes of objects are irreversibly erased from the output image.The success of class-specific diffractive cameras was experimentally demonstrated using terahertz(THz)waves and 3D-printed diffractive layers that selectively imaged only one class of the MNIST handwritten digit dataset,all-optically erasing the other handwritten digits.This diffractive camera design can be scaled to different parts of the electromagnetic spectrum,including,e.g.,the visible and infrared wavelengths,to provide transformative opportunities for privacy-preserving digital cameras and task-specific data-efficient imaging.展开更多
The power of controlling objects with mind has captivated a popular fascination to human beings.One possible path is to employ brain signal collecting technologies together with emerging programmable metasurfaces(PM),...The power of controlling objects with mind has captivated a popular fascination to human beings.One possible path is to employ brain signal collecting technologies together with emerging programmable metasurfaces(PM),whose functions or operating modes can be switched or customized via on-site programming or pre-defined software.Nevertheless,most of existing PMs are wire-connected to users,manually-controlled and not real-time.Here,we propose the concept of remotely mind-controlled metasurface(RMCM)via brainwaves.Rather than DC voltage from power supply or AC voltages from signal generators,the metasurface is controlled by brainwaves collected in real time and transmitted wirelessly from the user.As an example,we demonstrated a RMCM whose scattering pattern can be altered dynamically according to the user’s brain waves via Bluetooth.The attention intensity information is extracted as the control signal and a mapping between attention intensity and scattering pattern of the metasurface is established.With such a framework,we experimentally demonstrated and verified a prototype of such metasurface system which can be remotely controlled by the user to modify its scattering pattern.This work paves a new way to intelligent metasurfaces and may find applications in health monitoring,5G/6G communications,smart sensors,etc.展开更多
Brain-computer interfaces(BCIs),invasive or non-invasive,have projected unparalleled vision and promise for assisting patients in need to better their interaction with the surroundings.Inspired by the BCI-based rehabi...Brain-computer interfaces(BCIs),invasive or non-invasive,have projected unparalleled vision and promise for assisting patients in need to better their interaction with the surroundings.Inspired by the BCI-based rehabilitation technologies for nerve-system impairments and amputation,we propose an electromagnetic brain-computer-metasurface(EBCM)paradigm,regulated by human’s cognition by brain signals directly and non-invasively.We experimentally show that our EBCM platform can translate human’s mind from evoked potentials of P300-based electroencephalography to digital coding information in the electromagnetic domain non-invasively,which can be further processed and transported by an information metasurface in automated and wireless fashions.Directly wireless communications of the human minds are performed between two EBCM operators with accurate text transmissions.Moreover,several other proof-of-concept mind-control schemes are presented using the same EBCM platform,exhibiting flexibly-customized capabilities of information processing and synthesis like visual-beam scanning,wave modulations,and pattern encoding.展开更多
Recent progress in nanophotonics and material science has inspired a strong interest in optically-induced material dynamics,opening new research directions in the distinct fields of Floquet matter and time metamateria...Recent progress in nanophotonics and material science has inspired a strong interest in optically-induced material dynamics,opening new research directions in the distinct fields of Floquet matter and time metamaterials.Floquet phenomena are historically rooted in the condensed matter community,as they exploit periodic temporal drives to unveil novel phases of matter,unavailable in systems at equilibrium.In parallel,the field of metamaterials has been offering a platform for exotic wave phenomena based on tailored materials at the nanoscale,recently enhanced by incorporating time variations and switching as new degrees of freedom.In this Perspective,we connect these research areas and describe the exciting opportunities emerging from their synergy,hinging on giant wave-matter interactions enabled by metamaterials and on the exotic wave dynamics enabled by Floquet and parametric phenomena.We envision Floquet metamaterials in which nontrivial modulation dynamics,and their interplay with tailored material dispersion and nontrivial material properties such as anisotropy,non-Hermiticity and nonreciprocity,introduce a plethora of novel opportunities for wave manipulation and control.展开更多
The topological features of optical vortices have been opening opportunities for free-space and on-chip photonic technologies,e.g.,for multiplexed optical communications and robust information transport.In a parallel ...The topological features of optical vortices have been opening opportunities for free-space and on-chip photonic technologies,e.g.,for multiplexed optical communications and robust information transport.In a parallel but disjoint effort,polar anisotropic van der Waals nanomaterials supporting hyperbolic phonon polaritons(HP2s)have been leveraged to drastically boost light-matter interactions.So far HP2 studies have been mainly focusing on the control of their amplitude and scale features.Here we report the generation and observation of mid-infrared hyperbolic polariton vortices(HP2Vs)associated with reconfigurable topological charges.Spiral-shaped gold disks coated with a flake of hexagonal boron nitride are exploited to tailor spin-orbit interactions and realise deeply subwavelength HP2Vs.The complex interplay between excitation spin,spiral geometry and HP2 dispersion enables robust reconfigurability of the associated topological charges.Our results reveal unique opportunities to extend the application of HP2s into topological photonics,quantum information processing by integrating these phenomena with single-photon emitters,robust on-chip optical applications,sensing and nanoparticle manipulation.展开更多
Optics and photonics-enabling the human kind to answer basic questions such as"how can people see things"-has now evolved to be a main-stream discipline rather than a sub-topic of physics.In the past decades...Optics and photonics-enabling the human kind to answer basic questions such as"how can people see things"-has now evolved to be a main-stream discipline rather than a sub-topic of physics.In the past decades,more than 40 Nobel Prizes are awarded to optics-related researches.With UNESCO designating 2015 and May 16th as the International Year of Light and International Day of Light,respectively,we have witnessed how optical sciences and engineering of light prospered into a game changer in the wellbeing of human society,reshaping and fusing various disciplines including physics,biology,chemistry,biomedical sci-ences and engineering.Optics and photonics research has fundamentally reformed our understanding of the nature,and all these transformative advances have moti-vated us to start a new journal to timely showcase some of the emerging groundbreaking research driven by optics and photonics.展开更多
Nowadays,viral infections are one of the greatest challenges for medical sciences and human society.While antiviral compounds and chemical inactivation remain inadequate,physical approaches based on irradiation provid...Nowadays,viral infections are one of the greatest challenges for medical sciences and human society.While antiviral compounds and chemical inactivation remain inadequate,physical approaches based on irradiation provide new potentials for prevention and treatment of viral infections,without the risk of drug resistance and other unwanted side effects.Light across the electromagnetic spectrum can inactivate the virions using ionizing and non-ionizing radiations.This review highlights the anti-viral utility of radiant methods from the aspects of ionizing radiation,including high energy ultraviolet,gamma ray,X-ray,and neutron,and non-ionizing photo-inactivation,including lasers and blue light.展开更多
Nanophotonic platforms such as metasurfaces,achieving arbitrary phase profiles within ultrathin thickness,emerge as miniaturized,ultracompact and kaleidoscopic optical vortex generators.However,it is often required to...Nanophotonic platforms such as metasurfaces,achieving arbitrary phase profiles within ultrathin thickness,emerge as miniaturized,ultracompact and kaleidoscopic optical vortex generators.However,it is often required to segment or interleave independent sub-array metasurfaces to multiplex optical vortices in a single nano-device,which in turn affects the device’s compactness and channel capacity.Here,inspired by phyllotaxis patterns in pine cones and sunflowers,we theoretically prove and experimentally report that multiple optical vortices can be produced in a single compact phyllotaxis nanosieve,both in free space and on a chip,where one meta-atom may contribute to many vortices simultaneously.The time-resolved dynamics of on-chip interference wavefronts between multiple plasmonic vortices was revealed by ultrafast time-resolved photoemission electron microscopy.Our nature-inspired optical vortex generator would facilitate various vortex-related optical applications,including structured wavefront shaping,free-space and plasmonic vortices,and high-capacity information metaphotonics.展开更多
Two dimensional excitonic devices are of great potential to overcome the dilemma of response time and integration in current generation of electron or/and photon based systems.The ultrashort diffusion length of excito...Two dimensional excitonic devices are of great potential to overcome the dilemma of response time and integration in current generation of electron or/and photon based systems.The ultrashort diffusion length of exciton arising from ultrafast relaxation and low carrier mobility greatly discounts the performance of excitonic devices.Phonon scattering and exciton localization are crucial to understand the modulation of exciton flux in two dimensional disorder energy landscape,which still remain elusive.Here,we report an optimized scheme for exciton diffusion and relaxation dominated by phonon scattering and disorder potentials in WSe2 monolayers.The effective diffusion coefficient is enhanced by>200%at 280 K.The excitons tend to be localized by disorder potentials accompanied by the steadily weakening of phonon scattering when temperature drops to 260 K,and the onset of exciton localization brings forward as decreasing temperature.These findings identify that phonon scattering and disorder potentials are of great importance for long-range exciton diffusion and thermal management in exciton based systems,and lay a firm foundation for the development of functional excitonic devices.展开更多
The interaction between cell surface receptors and extracellular ligands is highly related to many physiological processes in living systems.Many techniques have been developed to measure the ligand-receptor binding k...The interaction between cell surface receptors and extracellular ligands is highly related to many physiological processes in living systems.Many techniques have been developed to measure the ligand-receptor binding kinetics at the single-cell level.However,few techniques can measure the physiologically relevant shear binding affinity over a single cell in the clinical environment.Here,we develop a new optical technique,termed single-cell rotational adhesion frequency assay(scRAFA),that mimics in vivo cell adhesion to achieve label-free determination of both homogeneous and heterogeneous binding kinetics of targeted cells at the subcellular level.Moreover,the scRAFA is also applicable to analyze the binding affinities on a single cell in native human biofluids.With its superior performance and general applicability,scRAFA is expected to find applications in study of the spatial organization of cell surface receptors and diagnosis of infectious diseases.展开更多
Optical metamaterials have presented an innovative method of manipulating light.Hyperbolic metamaterials have an extremely high anisotropy with a hyperbolic dispersion relation.They are able to support high-k modes an...Optical metamaterials have presented an innovative method of manipulating light.Hyperbolic metamaterials have an extremely high anisotropy with a hyperbolic dispersion relation.They are able to support high-k modes and exhibit a high density of states which produce distinctive properties that have been exploited in various applications,such as super-resolution imaging,negative refraction,and enhanced emission control.Here,state-of-the-art hyperbolic metamaterials are reviewed,starting from the fundamental principles to applications of artificially structured hyperbolic media to suggest ways to fuse natural two-dimensional hyperbolic materials.The review concludes by indicating the current challenges and our vision for future applications of hyperbolic metamaterials.展开更多
基金support from the National Key R&D Program of China under Grant(No.2017YFA0303800).MS acknowledges support from the Israel Science Foundation.
文摘Let there be light-to change the world we want to be!Over the past several decades,and ever since the birth of the first laser,mankind has witnessed the development of the science of light,as light-based technologies have revolutionarily changed our lives.Needless to say,photonics has now penetrated into many aspects of science and technology,turning into an important and dynamically changing field of increasing interdisciplinary interest.In this inaugural issue of eLight,we highlight a few emerging trends in photonics that we think are likely to have major impact at least in the upcoming decade,spanning from integrated quantum photonics and quantum computing,through topological/non-Hermitian photonics and topological insulator lasers,to AI-empowered nanophotonics and photonic machine learning.This Perspective is by no means an attempt to summarize all the latest advances in photonics,yet we wish our subjective vision could fuel inspiration and foster excitement in scientific research especially for young researchers who love the science of light.
基金We thank Iain Patten for valuable discussions on the structure and layout of the manuscript.IDS kindly acknowledges funding from the Life grant by Volkswagen Foundation(Grant No.92772).
文摘The use of optical tweezers to measure forces acting upon microscopic particles has revolutionised fields from material science to cell biology.However,despite optical control capabilities,this technology is highly constrained by the material properties of the probe,and its use may be limited due to concerns about the effect on biological processes.Here we present a novel,optically controlled trapping method based on light-induced hydrodynamic flows.Specifically,we leverage optical control capabilities to convert a translationally invariant topological defect of a flow field into an attractor for colloids in an effectively one-dimensional harmonic,yet freely rotatable system.Circumventing the need to stabilise particle dynamics along an unstable axis,this novel trap closely resembles the isotropic dynamics of optical tweezers.Using magnetic beads,we explicitly show the existence of a linear force-extension relationship that can be used to detect femtoNewton-range forces with sensitivity close to the thermal limit.Our force measurements remove the need for laser-particle contact,while also lifting material constraints,which renders them a particu-larly interesting tool for the life sciences and engineering.
基金Science and Technology Innovation Commission of Shenzhen(KQTD20170810110913065,20200925174735005)Australia China Science and Research Fund Joint Research Centre for Point-of-Care Testing(ACSRF658277,SQ2017YFGH001190)ARC Laureate Fellowship Program(D.J.,FL210100180)。
文摘Although small EVs(sEVs)have been used widely as biomarkers in disease diagnosis,their heterogeneity at single EV level has rarely been revealed.This is because high-resolution characterization of sEV presents a major challenge,as their sizes are below the optical diffraction limit.Here,we report that upconversion nanoparticles(UCNPs)can be used for super-resolution profiling the molecular heterogeneity of sEVs.We show that Er3+-doped UCNPs has better brightness and Tm3+-doped UCNPs resulting in better resolution beyond diffraction limit.Through an orthogonal experimental design,the specific targeting of UCNPs to the tumour epitope on single EV has been cross validated,resulting in the Pearson’s R-value of 0.83 for large EVs and~65%co-localization double-positive spots for sEVs.Furthermore,super-resolution nanoscopy can distinguish adjacent UCNPs on single sEV with a resolution of as high as 41.9 nm.When decreasing the size of UCNPs from 40 to 27 nm and 18 nm,we observed that the maximum UCNPs number on single sEV increased from 3 to 9 and 21,respectively.This work suggests the great potentials of UCNPs approach“digitally”quantify the surface antigens on single EVs,therefore providing a solution to monitor the EV heterogeneity changes along with the tumour progression progress.
基金National Natural Science Foundation of China(NSFC)(Grant Nos.61860206009,81870934,82001877,61975172,61735016,91632105,81961128029,81961138015)National Key Research and Development Program of China(2017YFA0700501)+2 种基金China Postdoctoral Science Foundation-funded project(Nos.BX20190131,2019M662633)Innovation Project of Optics Valley Laboratory(Grant No.OVL2021BG011)Funding from the Innovation Fund of WNLO,and Fundamental Research Funds for the Central Universities(Nos.2020-KYY-511108-0007,2019QNA5001).
文摘Modern optical imaging techniques provide powerful tools for observing cortical structure and functions at high resolutions.Various skull windows have been established for different applications of cortical imaging,and each has its advantages and limitations.Most critical of the limitations,none of the current skull windows is suitable for observing the responses to some acute craniocerebral injuries on a large scale and at high resolution.Here,we developed a“Through-Intact-Skull(TIS)window”that enables the observation of an immune response on a bilateral cortical scale and at single-cell resolution after traumatic brain injury without affecting the pathological environment of the brain.The TIS window also has the advantages of craniotomy-freeness,centimeter-field of view,synaptic resolution,large imaging depth,long-term observation capability,and suitability for awake mice.Therefore,the TIS window is a promising new approach for intravital cortical microscopy in basic research in neuroscience.
基金supported by the National Natural Science Foundation of China(Nos.61971045,61827901,61991451)National Key R&D Program(Grant No.2020YFB0505601)Fundamental Research Funds for the Central Universities(Grant No.3052019024).
文摘High-throughput computational imaging requires efficient processing algorithms to retrieve multi-dimensional and multi-scale information.In computational phase imaging,phase retrieval(PR)is required to reconstruct both amplitude and phase in complex space from intensity-only measurements.The existing PR algorithms suffer from the tradeoff among low computational complexity,robustness to measurement noise and strong generalization on different modalities.In this work,we report an efficient large-scale phase retrieval technique termed as LPR.It extends the plug-and-play generalized-alternating-projection framework from real space to nonlinear complex space.The alternating projection solver and enhancing neural network are respectively derived to tackle the measurement formation and statistical prior regularization.This framework compensates the shortcomings of each operator,so as to realize high-fidelity phase retrieval with low computational complexity and strong generalization.We applied the technique for a series of computational phase imaging modalities including coherent diffraction imaging,coded diffraction pattern imaging,and Fourier ptychographic microscopy.Extensive simulations and experiments validate that the technique outperforms the existing PR algorithms with as much as 17dB enhancement on signal-to-noise ratio,and more than one order-of-magnitude increased running efficiency.Besides,we for the first time demonstrate ultralarge-scale phase retrieval at the 8K level(7680×4320 pixels)in minute-level time.
基金This project is funded by Research Grants Council of the Hong Kong Special Administrative Region,China(HKU 17200219,HKU 17209018,E-HKU701/17,CityU T42-103/16-N,and HKU C7047-16G)Natural Science Foundation of China(N_HKU712/16)。
文摘Water plays a vital role in biological metabolism and it would be essential to trace the water content non-invasively,such as leveraging the vibrational absorption peak of the O-H bond.However,due to the lack of an efficient laser source,it was challenging to image the water content in the deep tissue with micron-level spatial resolution.To address this problem,we develop a high-power hybrid optical parametrically-oscillating emitter(HOPE)at 1930 nm,at which the vibrational absorption peak of the O-H bond locates.The maximum pulse energy is over 1.74μJ with a pulse repetition rate of 50 kHz and a pulse width of 15 ns.We employ this laser source in the optical-resolution photoacoustic microscopy(OR-PAM)system to image the water content in the phantom and the biological tissue in vitro.Our 1930-nm OR-PAM could map the water content in the complex tissue environment at high spatial resolution,deep penetration depth,improved sensitivity,and suppressed artifact signal of the lipid.
基金National Key Research and Development Program of China(2020YFA0710100)National Natural Science Foundation of China(62005231,92050102)Fundamental Research Funds for the Central Universities(20720210045,20720200074,20720220033,and 20720220134)。
文摘Whispering-gallery-mode(WGM)cavity is important for exploring physics of strong light-matter interaction.Yet it suffers from the notorious radiation loss universally due to the light tunneling effect through the curved boundary.In this work,we propose and demonstrate an optical black hole(OBH)cavity based on transformation optics.The radiation loss of all WGMs in the ideal OBH cavity is completely inhibited by an infinite wide potential barrier.Besides,the WGM field in the OBH cladding is revealed to follow 1/r decay rule based on conformal mapping,which is fundamentally different from the conventional Hankel-function distributions in a homogeneous cavity.Experimentally,a truncated OBH cavity is achieved based on the effective medium theory,and both the Q-factor enhancement and tightly confined WGM fields are measured in the microwave spectra which agree well with the theoretical results.The circular OBH cavity is further applied to the arbitrary-shaped cavities including single-core and multi-core structures with high-Q factor via the conformal mapping.The OBH cavity design strategy can be generalized to resonant modes of various wave systems,such as acoustic and elastic waves,and finds applications in energy harvesting and optoelectronics.
文摘Planar and ultrathin liquid crystal(LC)polarization optical elements have found promising applications in augmented reality(AR),virtual reality(VR),and photonic devices.In this paper,we give a comprehensive review on the operation principles,device fabrication,and performance of these optical elements.Optical simulations methods for optimizing the device performance are discussed in detail.Finally,some potential applications of these devices in AR and VR systems are illustrated and analyzed.
基金State Key Research Development Program of China(Grant No.2019YFB2203503)National Natural Science Fund(Grant Nos.61875138,61961136001,62104153,62105211 and U1801254)+2 种基金Natural Science Foundation of Guangdong Province(2018B030306038 and 2020A1515110373)Science and Technology Innovation Commission of Shenzhen(JCYJ20180507182047316 and 20200805132016001)Postdoctoral Science Foundation of China(No.2021M702237)。
文摘Neutron-transmutation doping(NTD)has been demonstrated for the first time in this work for substitutional introduction of tin(Sn)shallow donors into two-dimensional(2D)layered indium selenide(InSe)to manipulate electron transfer and charge carrier dynamics.Multidisciplinary study including density functional theory,transient optical absorption,and FET devices have been carried out to reveal that the field effect electron mobility of the fabricated phototransistor is increased 100-fold due to the smaller electron effective mass and longer electron life time in the Sn-doped InSe.The responsivity of the Sn-doped InSe based phototransistor is accordingly enhanced by about 50 times,being as high as 397 A/W.The results show that NTD is a highly effective and controllable doping method,possessing good compatibility with the semiconductor manufacturing process,even after device fabrication,and can be carried out without introducing any contamination,which is radically different from traditional doping methods.
基金The Ozcan Research Group at UCLA acknowledges the support of ONR(Grant#N00014-22-1-2016)Jarrahi Research Group at UCLA acknowledges the support of the Department of Energy(Grant#DE-SC0016925).
文摘Privacy protection is a growing concern in the digital era,with machine vision techniques widely used throughout public and private settings.Existing methods address this growing problem by,e.g.,encrypting camera images or obscuring/blurring the imaged information through digital algorithms.Here,we demonstrate a camera design that performs class-specific imaging of target objects with instantaneous all-optical erasure of other classes of objects.This diffractive camera consists of transmissive surfaces structured using deep learning to perform selective imaging of target classes of objects positioned at its input field-of-view.After their fabrication,the thin diffractive layers collectively perform optical mode filtering to accurately form images of the objects that belong to a target data class or group of classes,while instantaneously erasing objects of the other data classes at the output field-of-view.Using the same framework,we also demonstrate the design of class-specific permutation and class-specific linear transformation cameras,where the objects of a target data class are pixel-wise permuted or linearly transformed following an arbitrarily selected transformation matrix for all-optical class-specific encryption,while the other classes of objects are irreversibly erased from the output image.The success of class-specific diffractive cameras was experimentally demonstrated using terahertz(THz)waves and 3D-printed diffractive layers that selectively imaged only one class of the MNIST handwritten digit dataset,all-optically erasing the other handwritten digits.This diffractive camera design can be scaled to different parts of the electromagnetic spectrum,including,e.g.,the visible and infrared wavelengths,to provide transformative opportunities for privacy-preserving digital cameras and task-specific data-efficient imaging.
基金National Natural Science Foundation of China under Grant Nos.61971435,62101588,62101589National Key Research and Development Program of China(Grant No.:SQ2017YFA0700201)+1 种基金C.-W.Q.is supported by a grant(R-261-518-004-720|A-0005947-16-00)from Advanced Research and Technology Innovation Centre(ARTIC)in National University of Singapore.
文摘The power of controlling objects with mind has captivated a popular fascination to human beings.One possible path is to employ brain signal collecting technologies together with emerging programmable metasurfaces(PM),whose functions or operating modes can be switched or customized via on-site programming or pre-defined software.Nevertheless,most of existing PMs are wire-connected to users,manually-controlled and not real-time.Here,we propose the concept of remotely mind-controlled metasurface(RMCM)via brainwaves.Rather than DC voltage from power supply or AC voltages from signal generators,the metasurface is controlled by brainwaves collected in real time and transmitted wirelessly from the user.As an example,we demonstrated a RMCM whose scattering pattern can be altered dynamically according to the user’s brain waves via Bluetooth.The attention intensity information is extracted as the control signal and a mapping between attention intensity and scattering pattern of the metasurface is established.With such a framework,we experimentally demonstrated and verified a prototype of such metasurface system which can be remotely controlled by the user to modify its scattering pattern.This work paves a new way to intelligent metasurfaces and may find applications in health monitoring,5G/6G communications,smart sensors,etc.
基金National Key Research and Development Program of China(2017YFA0700201,2017YFA0700202,and 2017YFA0700203)Major Project of Natural Science Foundation of Jiangsu Province(BK20212002)+9 种基金National Natural Science Foundation of China(61871127,61735010,61731010,61890544,61801117,61722106,61701107,61701108,61701246,61631007,61633010,61876064,62076099,61731010,and 11874142)State Key Laboratory of Millimeter Waves,Southeast University,China(K201924)Fundamental Research Funds for the Central Universities(2242018R30001)111 Project(111-2-05)Fund for International Cooperation and Exchange of National Natural Science Foundation of China(61761136007)Key R&D Program of Guangdong Province(2018B030339001)Key Realm R&D Program of Guangzhou(202007030007)Guangdong Basic and Applied Basic Research Foundation(2019A1515011773)Pearl River S&T Nova Program of Guangzhou(201906010043)C.-W.Q.acknowledges the financial support from the grant R-261-518-004-720 from Advanced Research and Technology Innovation Centre(ARTIC)。
文摘Brain-computer interfaces(BCIs),invasive or non-invasive,have projected unparalleled vision and promise for assisting patients in need to better their interaction with the surroundings.Inspired by the BCI-based rehabilitation technologies for nerve-system impairments and amputation,we propose an electromagnetic brain-computer-metasurface(EBCM)paradigm,regulated by human’s cognition by brain signals directly and non-invasively.We experimentally show that our EBCM platform can translate human’s mind from evoked potentials of P300-based electroencephalography to digital coding information in the electromagnetic domain non-invasively,which can be further processed and transported by an information metasurface in automated and wireless fashions.Directly wireless communications of the human minds are performed between two EBCM operators with accurate text transmissions.Moreover,several other proof-of-concept mind-control schemes are presented using the same EBCM platform,exhibiting flexibly-customized capabilities of information processing and synthesis like visual-beam scanning,wave modulations,and pattern encoding.
文摘Recent progress in nanophotonics and material science has inspired a strong interest in optically-induced material dynamics,opening new research directions in the distinct fields of Floquet matter and time metamaterials.Floquet phenomena are historically rooted in the condensed matter community,as they exploit periodic temporal drives to unveil novel phases of matter,unavailable in systems at equilibrium.In parallel,the field of metamaterials has been offering a platform for exotic wave phenomena based on tailored materials at the nanoscale,recently enhanced by incorporating time variations and switching as new degrees of freedom.In this Perspective,we connect these research areas and describe the exciting opportunities emerging from their synergy,hinging on giant wave-matter interactions enabled by metamaterials and on the exotic wave dynamics enabled by Floquet and parametric phenomena.We envision Floquet metamaterials in which nontrivial modulation dynamics,and their interplay with tailored material dispersion and nontrivial material properties such as anisotropy,non-Hermiticity and nonreciprocity,introduce a plethora of novel opportunities for wave manipulation and control.
基金Office of Naval Research(Grant No.N00014-19-1-2011)Vannevar Bush Faculty Fellowship,Air Force Office of Scientific Research MURI program,A*STAR AME Young Individual Research Grant(YIRG,No.A2084c0172)+4 种基金National Research Foundation Singapore(CRP22-2019-0006)Advanced Research and Technology Innovation Centre(No.R-261-518-004-720)National Science Foundation under Grant No.2044281Elemental Strategy Initiative conducted by MEXT,Japan,Grant Number JPMXP0112101001JSPS KAKENHI Grant Number JP20H00354。
文摘The topological features of optical vortices have been opening opportunities for free-space and on-chip photonic technologies,e.g.,for multiplexed optical communications and robust information transport.In a parallel but disjoint effort,polar anisotropic van der Waals nanomaterials supporting hyperbolic phonon polaritons(HP2s)have been leveraged to drastically boost light-matter interactions.So far HP2 studies have been mainly focusing on the control of their amplitude and scale features.Here we report the generation and observation of mid-infrared hyperbolic polariton vortices(HP2Vs)associated with reconfigurable topological charges.Spiral-shaped gold disks coated with a flake of hexagonal boron nitride are exploited to tailor spin-orbit interactions and realise deeply subwavelength HP2Vs.The complex interplay between excitation spin,spiral geometry and HP2 dispersion enables robust reconfigurability of the associated topological charges.Our results reveal unique opportunities to extend the application of HP2s into topological photonics,quantum information processing by integrating these phenomena with single-photon emitters,robust on-chip optical applications,sensing and nanoparticle manipulation.
文摘Optics and photonics-enabling the human kind to answer basic questions such as"how can people see things"-has now evolved to be a main-stream discipline rather than a sub-topic of physics.In the past decades,more than 40 Nobel Prizes are awarded to optics-related researches.With UNESCO designating 2015 and May 16th as the International Year of Light and International Day of Light,respectively,we have witnessed how optical sciences and engineering of light prospered into a game changer in the wellbeing of human society,reshaping and fusing various disciplines including physics,biology,chemistry,biomedical sci-ences and engineering.Optics and photonics research has fundamentally reformed our understanding of the nature,and all these transformative advances have moti-vated us to start a new journal to timely showcase some of the emerging groundbreaking research driven by optics and photonics.
基金Australia China Science and Research Fund Joint Research Centre for Point-of-Care Testing(ACSRF658277,SQ2017YFGH001190)Science and Technology Innovation Commission of Shenzhen(KQTD20170810110913065)Australian Research Council Laureate Fellowship Program(D.J.,FL210100180).
文摘Nowadays,viral infections are one of the greatest challenges for medical sciences and human society.While antiviral compounds and chemical inactivation remain inadequate,physical approaches based on irradiation provide new potentials for prevention and treatment of viral infections,without the risk of drug resistance and other unwanted side effects.Light across the electromagnetic spectrum can inactivate the virions using ionizing and non-ionizing radiations.This review highlights the anti-viral utility of radiant methods from the aspects of ionizing radiation,including high energy ultraviolet,gamma ray,X-ray,and neutron,and non-ionizing photo-inactivation,including lasers and blue light.
基金supported by the National Research Foundation,Prime Minister’s Office,Singapore under Competitive Research Program Award NRF-CRP22-2019-0006the grant(R-261-518-004-720)from Advanced Research and Technology Innovation Centre(ARTIC)+4 种基金the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)-Project-ID 278162697-SFB 1242ERC Advanced Grant Complex Plan,BMBF,DFG and BW-Stiftungthe Research Grants Council of Hong Kong(CRF Grant No.C6013-18G)the City University of Hong Kong(Project No.9610434)the support from A*STAR under its AME YIRG Grant(Award No.A2084c0172).
文摘Nanophotonic platforms such as metasurfaces,achieving arbitrary phase profiles within ultrathin thickness,emerge as miniaturized,ultracompact and kaleidoscopic optical vortex generators.However,it is often required to segment or interleave independent sub-array metasurfaces to multiplex optical vortices in a single nano-device,which in turn affects the device’s compactness and channel capacity.Here,inspired by phyllotaxis patterns in pine cones and sunflowers,we theoretically prove and experimentally report that multiple optical vortices can be produced in a single compact phyllotaxis nanosieve,both in free space and on a chip,where one meta-atom may contribute to many vortices simultaneously.The time-resolved dynamics of on-chip interference wavefronts between multiple plasmonic vortices was revealed by ultrafast time-resolved photoemission electron microscopy.Our nature-inspired optical vortex generator would facilitate various vortex-related optical applications,including structured wavefront shaping,free-space and plasmonic vortices,and high-capacity information metaphotonics.
基金National Key Research and Development Program of China(Grant No.2017YFA0206000)eijing Natural Science Foundation(Grant No.Z180011)+1 种基金National Science Foundation of China(Grant Nos.12027807,12104241 and 61521004)roject funded by China Postdoctoral Science Foundation(Grant No.2019M660283)。
文摘Two dimensional excitonic devices are of great potential to overcome the dilemma of response time and integration in current generation of electron or/and photon based systems.The ultrashort diffusion length of exciton arising from ultrafast relaxation and low carrier mobility greatly discounts the performance of excitonic devices.Phonon scattering and exciton localization are crucial to understand the modulation of exciton flux in two dimensional disorder energy landscape,which still remain elusive.Here,we report an optimized scheme for exciton diffusion and relaxation dominated by phonon scattering and disorder potentials in WSe2 monolayers.The effective diffusion coefficient is enhanced by>200%at 280 K.The excitons tend to be localized by disorder potentials accompanied by the steadily weakening of phonon scattering when temperature drops to 260 K,and the onset of exciton localization brings forward as decreasing temperature.These findings identify that phonon scattering and disorder potentials are of great importance for long-range exciton diffusion and thermal management in exciton based systems,and lay a firm foundation for the development of functional excitonic devices.
基金Y.L.,H.D.,J.L.and Y.Z.acknowledge the financial support of National Institute of General Medical Sciences of the National Institutes of Health.(DP2GM128446)National Science Foundation(ECCS-2001650)X.L.,M.Y.acknowledge the financial support of National Natural Science Foundation of China(No.11874397).
文摘The interaction between cell surface receptors and extracellular ligands is highly related to many physiological processes in living systems.Many techniques have been developed to measure the ligand-receptor binding kinetics at the single-cell level.However,few techniques can measure the physiologically relevant shear binding affinity over a single cell in the clinical environment.Here,we develop a new optical technique,termed single-cell rotational adhesion frequency assay(scRAFA),that mimics in vivo cell adhesion to achieve label-free determination of both homogeneous and heterogeneous binding kinetics of targeted cells at the subcellular level.Moreover,the scRAFA is also applicable to analyze the binding affinities on a single cell in native human biofluids.With its superior performance and general applicability,scRAFA is expected to find applications in study of the spatial organization of cell surface receptors and diagnosis of infectious diseases.
基金POSCO-POSTECH-RIST Convergence Research Center program funded by POSCOPOSTECH-Samsung Semiconductor Research Center(IO201215-08187-01)funded by Samsung ElectronicsNational Research Foundation(NRF)grant(NRF-2019R1A2C3003129)funded by the Ministry of Science and ICT,Republic of Korea.
文摘Optical metamaterials have presented an innovative method of manipulating light.Hyperbolic metamaterials have an extremely high anisotropy with a hyperbolic dispersion relation.They are able to support high-k modes and exhibit a high density of states which produce distinctive properties that have been exploited in various applications,such as super-resolution imaging,negative refraction,and enhanced emission control.Here,state-of-the-art hyperbolic metamaterials are reviewed,starting from the fundamental principles to applications of artificially structured hyperbolic media to suggest ways to fuse natural two-dimensional hyperbolic materials.The review concludes by indicating the current challenges and our vision for future applications of hyperbolic metamaterials.
