Metal halide perovskites(MHPs),emerging as innovative and promising semiconductor materials with prominent optoelectronic properties,has been pioneering a new era of light management(ranging from emission,absorption,m...Metal halide perovskites(MHPs),emerging as innovative and promising semiconductor materials with prominent optoelectronic properties,has been pioneering a new era of light management(ranging from emission,absorption,modulation,to transmission)for next-generation optoelectronic technology.Notably,the exploration of fundamental characteristics of MHPs and their devices is the main research theme during the past decade,while in the next decade,it will be primarily critical to promote their implantation in the next-generation optoelectronics.In this review,we first retrospect the historical research milestones of MHPs and their optoelectronic devices.Thereafter,we introduce the origin of the unique optoelectronic features of MHPs,based on which we highlight the tunability of these features via regulating the phase,dimensionality,composition,and geometry of MHPs.Then,we show that owing to the convenient property control of MHPs,various optoelectronic devices with target performance can be designed.At last,we emphasize on the revolutionary applications of MHPs-based devices on the existing optoelectronic systems.This review demonstrates the key role of MHPs played in the development of modern optoelectronics,which is expected to inspire the novel research directions of MHPs and promote the widespread applications of MHPs in the next-generation optoelectronics.展开更多
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
Quasicrystal has attracted lots of attention since its discovery because of the mathematically non-periodic arrangement and physically unique diffraction patterns.By combining the quasi-periodic features of quasicryst...Quasicrystal has attracted lots of attention since its discovery because of the mathematically non-periodic arrangement and physically unique diffraction patterns.By combining the quasi-periodic features of quasicrystal and the special rotational symmetry with metasurface,many novel phenomena and applications are proposed such as optical spin-Hall effect,non-linear far-field radiation control,and broadband polarization conversion.However,the additional functions and effects brought by phase and amplitude modulation on quasicrystal arrangement still lack research.Here,we design and fabricate a dielectric quasicrystal metasurface which can simultaneously reconstruct holographic images and exhibit diffraction patterns by assembling the nanostructures in a quasi-periodic array.Most importantly,we combine the global arrangement of metasurfaces with the local responses(phase and amplitude)of meta-atoms for achieving the dual functionality.Furthermore,we also suppress the zero diffraction order in the far-field based on the quasi-momentum matching rule.The proposed method has great mathematical importance and explores new possibilities for multifunctional meta-devices for holographic display,optical switching and anti-counterfeiting.展开更多
Light absorption near a surface of conductive materials and nanostructures leads to the excitation of nonequilibrium,high-energy charge carriers:electrons above the Fermi level or holes below it.When remaining inside ...Light absorption near a surface of conductive materials and nanostructures leads to the excitation of nonequilibrium,high-energy charge carriers:electrons above the Fermi level or holes below it.When remaining inside a material,these so-called hot carriers result in nonlinear,Kerr-type,optical effects important for controlling light with light.They can also transfer into the surroundings of the nanostructures,resulting in photocurrent,or they can interact with adjacent molecules and media,inducing photochemical transformations.Understanding the dynamics of hot carriers and related effects in plasmonic nanostructures is important for the development of ultrafast detectors and nonlinear optical components,broadband photocatalysis,enhanced nanoscale optoelectronic devices,nanoscale and ultrafast temperature control,and other technologies of tomorrow.In this review,we will discuss the fundamentals of plasmonically-engendered hot electrons,focusing on the overlooked aspects,theoretical descriptions and experimental methods to study them,and describe prototypical processes and examples of most promising applications of hotelectron processes at the metal interfaces.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
Ultracompact entangled photon sources are pivotal to miniaturized quantum photonic devices.Van der Waals(vdW)nonlinear crystals promise efficient photon-pair generation and on-chip monolithic integration with nanophot...Ultracompact entangled photon sources are pivotal to miniaturized quantum photonic devices.Van der Waals(vdW)nonlinear crystals promise efficient photon-pair generation and on-chip monolithic integration with nanophotonic circuitry.However,it remains challenging to generate maximally entangled Bell states of photon pairs with high purity,generation rate,and fidelity required for practical applications.Here,we realize a polarization-entangled photon-pair source based on spontaneous parametric down conversion in an ultrathin rhombohedral tungsten disulfide(3R-WS2)crystal.This vdW entangled photonic source exhibits a high photon-pair purity with a coincidenceto-accidental ratio of above 800,a generation rate of 31 Hz,and two maximally polarization-entangled Bell states with fidelities exceeding 0.93 and entanglement degree over 0.97.These results stem from scalable optical nonlinearity,enhanced second-order susceptibility by electronic transitions,and a well-defined symmetry-enabled selection rule inherent in 3R-WS2.Our polarization entangled photon source can be integrated with photonic structures for generating more complex entangled states,thus paving an avenue for advanced quantum photonic systems toward computation and metrology.展开更多
The rapid development of optical frequency combs from their table-top origins towards chip-scale platforms has opened up exciting possibilities for comb functionalities outside laboratories.Enhanced nonlinear processe...The rapid development of optical frequency combs from their table-top origins towards chip-scale platforms has opened up exciting possibilities for comb functionalities outside laboratories.Enhanced nonlinear processes in microresonators have emerged as a mainstream comb-generating mechanism with compelling advantages in size,weight,and power consumption.The established understanding of gain and loss in nonlinear microresonators,along with recently developed ultralow-loss nonlinear photonic circuitry,has boosted the optical energy conversion efficiency of microresonator frequency comb(microcomb)devices from below a few percent to above 50%.This review summarizes the latest advances in novel photonic devices and pumping strategies that contribute to these milestones of microcomb efficiency.The resulting benefits for high-performance integration of comb applications are also discussed before summarizing the remaining challenges.展开更多
Coherent Raman scattering(CRS)microscopy is a chemical imaging modality that provides contrast based on intrinsic biomolecular vibrations.To date,endeavors on instrumentation have advanced CRS into a powerful analytic...Coherent Raman scattering(CRS)microscopy is a chemical imaging modality that provides contrast based on intrinsic biomolecular vibrations.To date,endeavors on instrumentation have advanced CRS into a powerful analytical tool for studies of cell functions and in situ clinical diagnosis.Nevertheless,the small cross-section of Raman scattering sets up a physical boundary for the design space of a CRS system,which trades off speed,signal fidelity and spectral bandwidth.The synergistic combination of instrumentation and computational approaches offers a way to break the trade-off.In this review,we first introduce coherent Raman scattering and recent instrumentation developments,then discuss current computational CRS imaging methods,including compressive micro-spectroscopy,computational volumetric imaging,as well as machine learning algorithms that improve system performance and decipher chemical information.We foresee a constant permeation of computational concepts and algorithms to push the capability boundary of CRS microscopy.展开更多
The wide application of optical spectroscopy makes miniaturized spectrometers with fundamental importance.The scalability,high-performance,low-cost,and small footprint are still contradicting each other and limiting t...The wide application of optical spectroscopy makes miniaturized spectrometers with fundamental importance.The scalability,high-performance,low-cost,and small footprint are still contradicting each other and limiting the applicability of miniaturized spectrometer for practical application.Here we propose a compact spectrometer that satisfies the four advantages.The device uses a fiber taper tip to generate complex leaky mode patterns within 1 mm length.The unique correspondence between the pattern and wavelength operates effectively for hundreds of nanometers spectral range while providing a spectral resolution around~1 pm.The integration of multiple taper tips enables hyperspectral imaging applications.The working range of our device can be further extended using different materials and detectors while keeping the similar architecture.展开更多
After publication of this article[1],it was brought to our attention that the first author’s name Yuqian Ding is incorrect,the correct name is Yuqiang Ding.
Structured light,particularly in the terahertz frequency range,holds considerable potential for a diverse range of applications.However,the generation and control of structured terahertz radiation pose major challenge...Structured light,particularly in the terahertz frequency range,holds considerable potential for a diverse range of applications.However,the generation and control of structured terahertz radiation pose major challenges.In this work,we demonstrate a novel programmable spintronic emitter that can flexibly generate a variety of structured terahertz waves.This is achieved through the precise and high-resolution programming of the magnetization pattern on the emitter’s surface,utilizing laser-assisted local field cooling of an exchange-biased ferromagnetic heterostructure.Moreover,we outline a generic design strategy for realizing specific complex structured terahertz fields in the far field.Our device successfully demonstrates the generation of terahertz waves with diverse structured polarization states,including spatially separated circular polarizations,azimuthal or radial polarization states,and a full Poincare beam.This innovation opens a new avenue for designing and generating structured terahertz radiations,with potential applications in terahertz microscopy,communication,quantum information,and light-matter interactions.展开更多
Recently,it has been demonstrated that thermoviscous flows can be used for a range of fine micromanipulations,such as moving the cytoplasm of cells and developing embryos,intracellular rheology,and femtonewton-range f...Recently,it has been demonstrated that thermoviscous flows can be used for a range of fine micromanipulations,such as moving the cytoplasm of cells and developing embryos,intracellular rheology,and femtonewton-range force measurements.These flows,also known as focused-light-induced cytoplasmic streaming(FLUCS),are induced by mid-infrared laser scanning of a temperature spot through the sample.However,localized laser scanning can inflict temperature perturbations of several Kelvins on the sample,potentially eliciting unspecific biological responses.In this study,we demonstrate how exploiting symmetry relations during laser scanning effectively disentangles laser heating and flow induction.We introduce flow-neutral scan sequences that use dynamic photothermal stimuli and spatiotemporal symmetry relations of scanning bridging up to three distinct time scales.We leverage further insights from a recently published analytical model of flow fields to present quasi-homogenous temperature distributions that leave flow lines and their local and directed character largely invariant.We present practical,intuitive solutions through predesigned sets of scan lines with near isothermal distributions and demonstrate that they are sufficient to generate and control flows in Caenorhabditis elegans embryos on a magnitude well in excess of endogenous flow velocities.Our results enable the separation of two previously tightly linked classes of physical stimuli,introduce a new,even less invasive standard for performing FLUCS perturbations,and pave the way for new unexplored avenues in the fields of soft matter and biomedicine.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
In vivo imaging of large-scale neuronal activity plays a pivotal role in unraveling the function of the brain’s circuitry.Multiphoton microscopy,a powerful tool for deep-tissue imaging,has received sustained interest...In vivo imaging of large-scale neuronal activity plays a pivotal role in unraveling the function of the brain’s circuitry.Multiphoton microscopy,a powerful tool for deep-tissue imaging,has received sustained interest in advancing its speed,field of view and imaging depth.However,to avoid thermal damage in scattering biological tissue,field of view decreases exponentially as imaging depth increases.We present a suite of innovations to optimize three-photon microscopy for large field-of-view imaging at depths unreachable by two-photon microscopy.These techniques enable us to image neuronal activities of transgenic animals expressing protein calcium sensors in a~3.5-mm diameter field-of-view with single-cell resolution in the deepest cortical layer of mouse brains.We further demonstrate simultaneous large field-of-view two-photon and three-photon imaging,subcortical imaging in the mouse brain,and whole-brain imaging in adult zebrafish.The demonstrated techniques can be integrated into typical multiphoton microscopes to enlarge field of view for system-level neural circuit research.展开更多
Chirality,defined by Lord Kelvin,refers to the geometric symmetry property of an object that cannot be superposed onto its mirror image using rotations and translations.The material’s chirality can be probed with lig...Chirality,defined by Lord Kelvin,refers to the geometric symmetry property of an object that cannot be superposed onto its mirror image using rotations and translations.The material’s chirality can be probed with light as the optical activity:optical rotary dispersion(ORD)and circular dichroism(CD).It is still challenging to yield extremely sensitive ORD and CD for very weak chirality and measure both simultaneously.Cavity ringdown polarimetry has been reported to improve ORD detection sensitivity with the absence of equally important CD signature,at the price of high cavity finesse near 400,frequency-locking sophistication,and large magnetic field.Here,we report a unique recipe to demonstrate the simultaneous measurement of ORD and the CD by separately observing the chiral eigenmode spectra from a bowtie optical cavity with a finesse about 30,without resorting to frequency locking or magnetic field.We obtain a sensitivity of2.7×10^(−3)deg/√Hz for ORD,8.1×10^(−6)/√Hz for CD,and a spectral resolution of 0.04 pm within a millisecond-scale measurement.We present a cost-effective yet ultrasensitive account for chiral chromatography,the conformational dynamics and chiroptical analysis of biological samples which particularly exhibit weak and narrow spectral signals.展开更多
X-ray ptychographic tomography is a nondestructive method for three dimensional(3D)imaging with nanometer-sized resolvable features.The size of the volume that can be imaged is almost arbitrary,limited only by the pen...X-ray ptychographic tomography is a nondestructive method for three dimensional(3D)imaging with nanometer-sized resolvable features.The size of the volume that can be imaged is almost arbitrary,limited only by the penetration depth and the available scanning time.Here we present a method that rapidly accelerates the imaging operation over a given volume through acquiring a limited set of data via large angular reduction and compensating for the resulting ill-posedness through deeply learned priors.The proposed 3D reconstruction method“RAPID”relies initially on a subset of the object measured with the nominal number of required illumination angles and treats the reconstructions from the conventional two-step approach as ground truth.It is then trained to reproduce equal fidelity from much fewer angles.After training,it performs with similar fidelity on the hitherto unexamined portions of the object,previously not shown during training,with a limited set of acquisitions.In our experimental demonstration,the nominal number of angles was 349 and the reduced number of angles was 21,resulting in a×140 aggregate speedup over a volume of 4.48×93.18×3.92μm^(3) and with(14 nm)^(3) feature size,i.e.-10^(8) voxels.RAPID’s key distinguishing feature over earlier attempts is the incorporation of atrous spatial pyramid pooling modules into the deep neural network framework in an anisotropic way.We found that adjusting the atrous rate improves reconstruction fidelity because it expands the convolutional kernels’range to match the physics of multi-slice ptychography without significantly increasing the number of parameters.展开更多
Water is an essential component of the Earth’s climate,but monitoring its properties using autonomous underwater sampling robots remains a significant challenge due to lack of underwater geolocalization capabilities....Water is an essential component of the Earth’s climate,but monitoring its properties using autonomous underwater sampling robots remains a significant challenge due to lack of underwater geolocalization capabilities.Current methods for underwater geolocalization rely on tethered systems with limited coverage or daytime imagery data in clear waters,leaving much of the underwater environment unexplored.Geolocalization in turbid waters or at night has been considered unfeasible due to absence of identifiable landmarks.In this paper,we present a novel method for underwater geolocalization using deep neural networks trained on-10 million polarization-sensitive images acquired globally,along with camera position sensor data.Our approach achieves longitudinal accuracy of-55 km(-1000 km)during daytime(nighttime)at depths up to-8 m,regardless of water turbidity.In clear waters,the transfer learning longitudinal accuracy is-255 km at 50 m depth.By leveraging optical data in conjunction with camera position information,our novel method facilitates underwater geolocalization and offers a valuable tool for untethered underwater navigation.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
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
基金financially supported by the Natural Science Foundation of China(Grants 51972172,61705102,and 51802253)the China Postdoctoral Science Foundation(Grants 2021M692630)+6 种基金Natural Science Basic Research Plan in Shaanxi Province of China(2022JQ-629,2021JLM-43)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z-007 and 2020GXLH-Z-014)Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars,China(Grant BK20200034)the Innovation Project of Optics Valley Laboratory(OVL2021BG006)the Open Project Program of Wuhan National Laboratory for Optoelectronics(2021WNLOKF003)the Young 1000 Talents Global Recruitment Program of Chinathe Fundamental Research Funds for the Central Universities.
文摘Metal halide perovskites(MHPs),emerging as innovative and promising semiconductor materials with prominent optoelectronic properties,has been pioneering a new era of light management(ranging from emission,absorption,modulation,to transmission)for next-generation optoelectronic technology.Notably,the exploration of fundamental characteristics of MHPs and their devices is the main research theme during the past decade,while in the next decade,it will be primarily critical to promote their implantation in the next-generation optoelectronics.In this review,we first retrospect the historical research milestones of MHPs and their optoelectronic devices.Thereafter,we introduce the origin of the unique optoelectronic features of MHPs,based on which we highlight the tunability of these features via regulating the phase,dimensionality,composition,and geometry of MHPs.Then,we show that owing to the convenient property control of MHPs,various optoelectronic devices with target performance can be designed.At last,we emphasize on the revolutionary applications of MHPs-based devices on the existing optoelectronic systems.This review demonstrates the key role of MHPs played in the development of modern optoelectronics,which is expected to inspire the novel research directions of MHPs and promote the widespread applications of MHPs in the next-generation optoelectronics.
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the funding provided by the National Key R&D Program of China(2021YFB2802200)Beijing Outstanding Young Scientist Program(BJJWZYJH01201910007022)+3 种基金National Natural Science Foundation of China(No.U21A20140,No.92050117)program,Fok Ying-Tong Education Foundation of China(No.161009)Beijing Municipal Science&Technology Commission,Administrative Commission of Zhongguancun Science Park(No.Z211100004821009)Science and Technology Innovation Program of Beijing Institute of Technology(2021CX01008)supported by the Synergetic Extreme Condition User Facility(SECUF).We also acknowledge the fabrication and measurement service in the Analysis&Testing Center,Beijing Institute of Technology.
文摘Quasicrystal has attracted lots of attention since its discovery because of the mathematically non-periodic arrangement and physically unique diffraction patterns.By combining the quasi-periodic features of quasicrystal and the special rotational symmetry with metasurface,many novel phenomena and applications are proposed such as optical spin-Hall effect,non-linear far-field radiation control,and broadband polarization conversion.However,the additional functions and effects brought by phase and amplitude modulation on quasicrystal arrangement still lack research.Here,we design and fabricate a dielectric quasicrystal metasurface which can simultaneously reconstruct holographic images and exhibit diffraction patterns by assembling the nanostructures in a quasi-periodic array.Most importantly,we combine the global arrangement of metasurfaces with the local responses(phase and amplitude)of meta-atoms for achieving the dual functionality.Furthermore,we also suppress the zero diffraction order in the far-field based on the quasi-momentum matching rule.The proposed method has great mathematical importance and explores new possibilities for multifunctional meta-devices for holographic display,optical switching and anti-counterfeiting.
基金UKRI EPSRC projects EP/W017075/1 and EP/Y015673/1.
文摘Light absorption near a surface of conductive materials and nanostructures leads to the excitation of nonequilibrium,high-energy charge carriers:electrons above the Fermi level or holes below it.When remaining inside a material,these so-called hot carriers result in nonlinear,Kerr-type,optical effects important for controlling light with light.They can also transfer into the surroundings of the nanostructures,resulting in photocurrent,or they can interact with adjacent molecules and media,inducing photochemical transformations.Understanding the dynamics of hot carriers and related effects in plasmonic nanostructures is important for the development of ultrafast detectors and nonlinear optical components,broadband photocatalysis,enhanced nanoscale optoelectronic devices,nanoscale and ultrafast temperature control,and other technologies of tomorrow.In this review,we will discuss the fundamentals of plasmonically-engendered hot electrons,focusing on the overlooked aspects,theoretical descriptions and experimental methods to study them,and describe prototypical processes and examples of most promising applications of hotelectron processes at the metal interfaces.
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support from National Key Research and Development Program of China(2022YFA1204704)the Innovation Program for Quantum Science and Technology(2021ZD0303200,2021ZD0301500)+5 种基金the National Natural Science Foundation of China(NSFC)(62061160487,T2325022,U23A2074,62205325)the CAS Project for Young Scientists in Basic Research(No.YSBR-049)Key Research and Development Program of Anhui Province(2022b1302007)the Fundamental Research Funds for the Central Universitiessupport from the NRF,Prime Minister’s Office,Singapore under the Competitive Research Program Award(Grant No.NRF-CRP26-2021-0004)A*STAR SERC MTC Programmatic Funds under grant number M23M2b0056.C.-W.Q.acknowledges financial support from the NRF,Prime Minister’s Office,Singapore under the Competitive Research Program Award(NRF-CRP22-2019-0006 and NRF-CRP30-2023-0003).
文摘Ultracompact entangled photon sources are pivotal to miniaturized quantum photonic devices.Van der Waals(vdW)nonlinear crystals promise efficient photon-pair generation and on-chip monolithic integration with nanophotonic circuitry.However,it remains challenging to generate maximally entangled Bell states of photon pairs with high purity,generation rate,and fidelity required for practical applications.Here,we realize a polarization-entangled photon-pair source based on spontaneous parametric down conversion in an ultrathin rhombohedral tungsten disulfide(3R-WS2)crystal.This vdW entangled photonic source exhibits a high photon-pair purity with a coincidenceto-accidental ratio of above 800,a generation rate of 31 Hz,and two maximally polarization-entangled Bell states with fidelities exceeding 0.93 and entanglement degree over 0.97.These results stem from scalable optical nonlinearity,enhanced second-order susceptibility by electronic transitions,and a well-defined symmetry-enabled selection rule inherent in 3R-WS2.Our polarization entangled photon source can be integrated with photonic structures for generating more complex entangled states,thus paving an avenue for advanced quantum photonic systems toward computation and metrology.
基金supported by Beijing Natural Science Foundation(Z210004)National Natural Science Foundation of China(92150108)+2 种基金supported by European Research Council(CoG GA 771410)Swedish Research Council(project 2020-00453)Knut and Alice Wallenberg Foundation(KAW 2018.0090).
文摘The rapid development of optical frequency combs from their table-top origins towards chip-scale platforms has opened up exciting possibilities for comb functionalities outside laboratories.Enhanced nonlinear processes in microresonators have emerged as a mainstream comb-generating mechanism with compelling advantages in size,weight,and power consumption.The established understanding of gain and loss in nonlinear microresonators,along with recently developed ultralow-loss nonlinear photonic circuitry,has boosted the optical energy conversion efficiency of microresonator frequency comb(microcomb)devices from below a few percent to above 50%.This review summarizes the latest advances in novel photonic devices and pumping strategies that contribute to these milestones of microcomb efficiency.The resulting benefits for high-performance integration of comb applications are also discussed before summarizing the remaining challenges.
文摘Coherent Raman scattering(CRS)microscopy is a chemical imaging modality that provides contrast based on intrinsic biomolecular vibrations.To date,endeavors on instrumentation have advanced CRS into a powerful analytical tool for studies of cell functions and in situ clinical diagnosis.Nevertheless,the small cross-section of Raman scattering sets up a physical boundary for the design space of a CRS system,which trades off speed,signal fidelity and spectral bandwidth.The synergistic combination of instrumentation and computational approaches offers a way to break the trade-off.In this review,we first introduce coherent Raman scattering and recent instrumentation developments,then discuss current computational CRS imaging methods,including compressive micro-spectroscopy,computational volumetric imaging,as well as machine learning algorithms that improve system performance and decipher chemical information.We foresee a constant permeation of computational concepts and algorithms to push the capability boundary of CRS microscopy.
基金National Natural Science Foundation of China(NSFC)(62222511,61905213)Natural Science Foundation of Zhejiang Province China(LR22F050006).
文摘The wide application of optical spectroscopy makes miniaturized spectrometers with fundamental importance.The scalability,high-performance,low-cost,and small footprint are still contradicting each other and limiting the applicability of miniaturized spectrometer for practical application.Here we propose a compact spectrometer that satisfies the four advantages.The device uses a fiber taper tip to generate complex leaky mode patterns within 1 mm length.The unique correspondence between the pattern and wavelength operates effectively for hundreds of nanometers spectral range while providing a spectral resolution around~1 pm.The integration of multiple taper tips enables hyperspectral imaging applications.The working range of our device can be further extended using different materials and detectors while keeping the similar architecture.
文摘After publication of this article[1],it was brought to our attention that the first author’s name Yuqian Ding is incorrect,the correct name is Yuqiang Ding.
基金support from the National Key Research and Development Program of China(Grant No.2022YFA1404700)Z.T.also acknowledges the support from the National Key Research and Development Program of China(Grant No.2021YFA1400200)+8 种基金the National Natural Science Foundation of China(No.12274091)L.Z.,Y.W.and Z.T.acknowledge the support from the National Natural Science Foundation of China(Grant No.12221004)Y.W.and Z.T.acknowledge the support from the Shanghai Municipal Science and Technology Basic Research Project(Grant No.22JC1400200)Y.Z.acknowledges the support from the National Natural Science Foundation of China(Grant No.121774271)L.Z.acknowledges the support from the National Natural Science Foundation of China(Grant No.62192771)Y.W.acknowledges the support from the National Key Research Program of China(Grant No.2022YFA1403300)the National Natural Science Foundation of China(Grants No.11974079,No.12274083)the Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)L.Z.,Y.W.and Z.T.acknowledge the support from the Shanghai Municipal Science and Technology(Grant No.23dz2260100).
文摘Structured light,particularly in the terahertz frequency range,holds considerable potential for a diverse range of applications.However,the generation and control of structured terahertz radiation pose major challenges.In this work,we demonstrate a novel programmable spintronic emitter that can flexibly generate a variety of structured terahertz waves.This is achieved through the precise and high-resolution programming of the magnetization pattern on the emitter’s surface,utilizing laser-assisted local field cooling of an exchange-biased ferromagnetic heterostructure.Moreover,we outline a generic design strategy for realizing specific complex structured terahertz fields in the far field.Our device successfully demonstrates the generation of terahertz waves with diverse structured polarization states,including spatially separated circular polarizations,azimuthal or radial polarization states,and a full Poincare beam.This innovation opens a new avenue for designing and generating structured terahertz radiations,with potential applications in terahertz microscopy,communication,quantum information,and light-matter interactions.
基金funding by the Max Planck Society,the Karlsruhe Institute of Technologysupport by the European Research Council,in particular the ERC Starting Grant GHOSTs(Grant No.853619)+4 种基金support by the Volkswagen Foundation(Life!Grant No.92772)the Max Planck Society,Karlsruhe Institute of Technologythe Hector Foundationfunding by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Germany’s Excellence Strategy-2082/1-390761711funding from the Engineering and Physical Sciences Research Council(EPSRC studentship).
文摘Recently,it has been demonstrated that thermoviscous flows can be used for a range of fine micromanipulations,such as moving the cytoplasm of cells and developing embryos,intracellular rheology,and femtonewton-range force measurements.These flows,also known as focused-light-induced cytoplasmic streaming(FLUCS),are induced by mid-infrared laser scanning of a temperature spot through the sample.However,localized laser scanning can inflict temperature perturbations of several Kelvins on the sample,potentially eliciting unspecific biological responses.In this study,we demonstrate how exploiting symmetry relations during laser scanning effectively disentangles laser heating and flow induction.We introduce flow-neutral scan sequences that use dynamic photothermal stimuli and spatiotemporal symmetry relations of scanning bridging up to three distinct time scales.We leverage further insights from a recently published analytical model of flow fields to present quasi-homogenous temperature distributions that leave flow lines and their local and directed character largely invariant.We present practical,intuitive solutions through predesigned sets of scan lines with near isothermal distributions and demonstrate that they are sufficient to generate and control flows in Caenorhabditis elegans embryos on a magnitude well in excess of endogenous flow velocities.Our results enable the separation of two previously tightly linked classes of physical stimuli,introduce a new,even less invasive standard for performing FLUCS perturbations,and pave the way for new unexplored avenues in the fields of soft matter and biomedicine.
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National Science Foundation NeuroNex(Grant No.DBI-1707312 to C.X.).NIH/NINDS(Grant No.U01NS103516 to C.X.).Cornell Neurotech Mong Fellowship to A.M.
文摘In vivo imaging of large-scale neuronal activity plays a pivotal role in unraveling the function of the brain’s circuitry.Multiphoton microscopy,a powerful tool for deep-tissue imaging,has received sustained interest in advancing its speed,field of view and imaging depth.However,to avoid thermal damage in scattering biological tissue,field of view decreases exponentially as imaging depth increases.We present a suite of innovations to optimize three-photon microscopy for large field-of-view imaging at depths unreachable by two-photon microscopy.These techniques enable us to image neuronal activities of transgenic animals expressing protein calcium sensors in a~3.5-mm diameter field-of-view with single-cell resolution in the deepest cortical layer of mouse brains.We further demonstrate simultaneous large field-of-view two-photon and three-photon imaging,subcortical imaging in the mouse brain,and whole-brain imaging in adult zebrafish.The demonstrated techniques can be integrated into typical multiphoton microscopes to enlarge field of view for system-level neural circuit research.
基金supported by the National Key R&D Program of China(Grants No.2022YFA1405000,No.2019YFA0308700)the National Natural Science Foundation of China(Grants No.92365107,No.12305020,and No.11890704)+5 种基金the Program for Innovative Talents and Teams in Jiangsu(Grant No.JSSCTD202138)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301400)China Postdoctoral Science Foundation(Grant No.2023M731613)Jiangsu Funding Program for Excellent Postdoctoral Talent(Grant No.2023ZB708)C.-W.Q.is supported by the Competitive Research Program Award(NRF-CRP22-2019-0006&NRF-CRP26-2021-0004)from the NRF,Prime Minister’s Office,Singaporeby a grant(A-0005947-16-00)from A*STAR MTC IRG(M22K2c0088 with A-8001322-00-00).
文摘Chirality,defined by Lord Kelvin,refers to the geometric symmetry property of an object that cannot be superposed onto its mirror image using rotations and translations.The material’s chirality can be probed with light as the optical activity:optical rotary dispersion(ORD)and circular dichroism(CD).It is still challenging to yield extremely sensitive ORD and CD for very weak chirality and measure both simultaneously.Cavity ringdown polarimetry has been reported to improve ORD detection sensitivity with the absence of equally important CD signature,at the price of high cavity finesse near 400,frequency-locking sophistication,and large magnetic field.Here,we report a unique recipe to demonstrate the simultaneous measurement of ORD and the CD by separately observing the chiral eigenmode spectra from a bowtie optical cavity with a finesse about 30,without resorting to frequency locking or magnetic field.We obtain a sensitivity of2.7×10^(−3)deg/√Hz for ORD,8.1×10^(−6)/√Hz for CD,and a spectral resolution of 0.04 pm within a millisecond-scale measurement.We present a cost-effective yet ultrasensitive account for chiral chromatography,the conformational dynamics and chiroptical analysis of biological samples which particularly exhibit weak and narrow spectral signals.
基金funded by the Intelligence Advanced Research Projects Activity,Office of the Director of National Intelligence(IARPA-ODNI)under contract FA8650-17-C-9113.
文摘X-ray ptychographic tomography is a nondestructive method for three dimensional(3D)imaging with nanometer-sized resolvable features.The size of the volume that can be imaged is almost arbitrary,limited only by the penetration depth and the available scanning time.Here we present a method that rapidly accelerates the imaging operation over a given volume through acquiring a limited set of data via large angular reduction and compensating for the resulting ill-posedness through deeply learned priors.The proposed 3D reconstruction method“RAPID”relies initially on a subset of the object measured with the nominal number of required illumination angles and treats the reconstructions from the conventional two-step approach as ground truth.It is then trained to reproduce equal fidelity from much fewer angles.After training,it performs with similar fidelity on the hitherto unexamined portions of the object,previously not shown during training,with a limited set of acquisitions.In our experimental demonstration,the nominal number of angles was 349 and the reduced number of angles was 21,resulting in a×140 aggregate speedup over a volume of 4.48×93.18×3.92μm^(3) and with(14 nm)^(3) feature size,i.e.-10^(8) voxels.RAPID’s key distinguishing feature over earlier attempts is the incorporation of atrous spatial pyramid pooling modules into the deep neural network framework in an anisotropic way.We found that adjusting the atrous rate improves reconstruction fidelity because it expands the convolutional kernels’range to match the physics of multi-slice ptychography without significantly increasing the number of parameters.
基金funded by grants from the Office of Naval Research(N00014-19-1-2400 and N00014-21-1-2177)U.S.Air Force Office of Scientific Research(FA9550-18-1-0278).
文摘Water is an essential component of the Earth’s climate,but monitoring its properties using autonomous underwater sampling robots remains a significant challenge due to lack of underwater geolocalization capabilities.Current methods for underwater geolocalization rely on tethered systems with limited coverage or daytime imagery data in clear waters,leaving much of the underwater environment unexplored.Geolocalization in turbid waters or at night has been considered unfeasible due to absence of identifiable landmarks.In this paper,we present a novel method for underwater geolocalization using deep neural networks trained on-10 million polarization-sensitive images acquired globally,along with camera position sensor data.Our approach achieves longitudinal accuracy of-55 km(-1000 km)during daytime(nighttime)at depths up to-8 m,regardless of water turbidity.In clear waters,the transfer learning longitudinal accuracy is-255 km at 50 m depth.By leveraging optical data in conjunction with camera position information,our novel method facilitates underwater geolocalization and offers a valuable tool for untethered underwater navigation.
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.
