Modeling soil salinity in an arid salt-affected ecosystem is a difficult task when using remote sensing data because of the complicated soil context （vegetation cover, moisture, surface roughness, and organic matter...Modeling soil salinity in an arid salt-affected ecosystem is a difficult task when using remote sensing data because of the complicated soil context （vegetation cover, moisture, surface roughness, and organic matter） and the weak spectral features of salinized soil. Therefore, an index such as the salinity index （SI） that only uses soil spectra may not detect soil salinity effectively and quantitatively. The use of vegetation reflectance as an indirect indicator can avoid limitations associated with the direct use of soil reflectance. The normalized difference vegetation index （NDVI）, as the most common vegetation index, was found to be responsive to salinity but may not be available for retrieving sparse vegetation due to its sensitivity to background soil in arid areas. Therefore, the arid fraction integrated index （AFⅡ） was created as supported by the spectral mixture analysis （SMA）, which is more appropriate for analyzing variations in vegetation cover （particularly halophytes） than NDVI in the study area. Using soil and vegetation separately for detecting salinity perhaps is not feasible. Then, we developed a new and operational model, the soil salinity detecting model （SDM） that combines AFⅡ and SI to quantitatively estimate the salt content in the surface soil. SDMs, including SDM1 and SDM2, were constructed through analyzing the spatial characteristics of soils with different salinization degree by integrating AFⅡ and SI using a scatterplot. The SDMs were then compared to the combined spectral response index （COSRI） from field measurements with respect to the soil salt content. The results indicate that the SDM values are highly correlated with soil salinity, in contrast to the performance of COSRI. Strong exponential relationships were observed between soil salinity and SDMs （R2〉0.86, RMSE〈6.86） compared to COSRI （R2=0.71, RMSE=16.21）. These results suggest that the feature space related to biophysical properties combined with AFII and SI can effectively provide information on soil salinity.展开更多
The use of low-coherence light is expected to be one of the effective ways to suppress or even eliminate the laser–plasma instabilities that arise in attempts to achieve inertial confinement fusion.In this paper,a re...The use of low-coherence light is expected to be one of the effective ways to suppress or even eliminate the laser–plasma instabilities that arise in attempts to achieve inertial confinement fusion.In this paper,a review of low-coherence high-power laser drivers and related key techniques is first presented.Work at typical low-coherence laser facilities,including Gekko XII,PHEBUS,Pharos III,and Kanal-2 is described.The many key techniques that are used in the research and development of low-coherence laser drivers are described and analyzed,including low-coherence source generation,amplification,harmonic conversion,and beam smoothing of low-coherence light.Then,recent progress achieved by our group in research on a broadband low-coherence laser driver is presented.During the development of our low-coherence high-power laser facility,we have proposed and implemented many key techniques for working with low-coherence light,including source generation,efficient amplification and propagation,harmonic conversion,beam smoothing,and precise beam control.Based on a series of technological breakthroughs,a kilojoule low-coherence laser driver named Kunwu with a coherence time of only 300 fs has been built,and the first round of physical experiments has been completed.This high-power laser facility provides not only a demonstration and verification platform for key techniques and system integration of a low-coherence laser driver,but also a new type of experimental platform for research into,for example,high-energy-density physics and,in particular,laser–plasma interactions.展开更多
A simple,convenient,and highly sensitive bio-interface for graphene field-effect transistors(GFETs) based on multifunctional nano-denatured bovine serum albumin(nano-dBSA) functionalization was developed to target can...A simple,convenient,and highly sensitive bio-interface for graphene field-effect transistors(GFETs) based on multifunctional nano-denatured bovine serum albumin(nano-dBSA) functionalization was developed to target cancer bio-markers.The novel graphene–protein bioelectronic interface was constructed by heating to denature native BSA on the graphene substrate surface.The formed nano-d BSA film served as the cross-linker to immobilize monoclonal antibody against car-cinoembryonic antigen(anti-CEA mAb) on the graphene channel activated by EDC and Sulfo-NHS.The nano-dBSA film worked as a self-protecting layer of graphene to prevent surface contamination by lithographic processing.The improved GFETbiosensor exhibited good specificity and high sensitivity toward the target at an ultralow concentration of 337.58 fg mL-1.The electrical detection of the binding of CEA followed the Hill model for ligand–receptor interaction,indicating the negative binding cooperativity between CEA and anti-CEA mAb with a dissociation constant of 6.82×10-10M.The multifunctional nano-dBSA functionalization can confer a new function to graphene-like 2D nanomaterials and provide a promising bio-functionalization method for clinical application in biosensing,nanomedicine,and drug delivery.展开更多
Perfect vector beams are a class of special vector beams with invariant radius and intensity profiles under changing topological charges.However,with the limitation of current devices,the generation of these vector be...Perfect vector beams are a class of special vector beams with invariant radius and intensity profiles under changing topological charges.However,with the limitation of current devices,the generation of these vector beams is limited in the visible and infrared wavebands.Herein,we generate perfect vector beams in the ultraviolet region assisted by nonlinear frequency conversion.Experimental and simulation results show that the radius of the generated ultraviolet perfect vector beams remains invariant and is thus independent of the topological charge.Furthermore,we measure the power of the generated ultraviolet perfect vector beams with the change of their topological charges.This study provides an alternative approach to generating perfect vector beams for ultraviolet wavebands and may promote their application to optical trapping and optical communication.展开更多
Stirred reactors are key equipment in production,and unpredictable failures will result in significant economic losses and safety issues.Therefore,it is necessary to monitor its health state.To achieve this goal,in th...Stirred reactors are key equipment in production,and unpredictable failures will result in significant economic losses and safety issues.Therefore,it is necessary to monitor its health state.To achieve this goal,in this study,five states of the stirred reactor were firstly preset:normal,shaft bending,blade eccentricity,bearing wear,and bolt looseness.Vibration signals along x,y and z axes were collected and analyzed in both the time domain and frequency domain.Secondly,93 statistical features were extracted and evaluated by ReliefF,Maximal Information Coefficient(MIC)and XGBoost.The above evaluation results were then fused by D-S evidence theory to extract the final 16 features that are most relevant to the state of the stirred reactor.Finally,the CatBoost algorithm was introduced to establish the stirred reactor health monitoring model.The validation results showed that the model achieves 100%accuracy in detecting the fault/normal state of the stirred reactor and 98%accuracy in diagnosing the type of fault.展开更多
The mode sorter is the crucial component of the communication systems based on orbital angular momentum(OAM).However,schemes proposed so far can only effectively sort integer OAM(IOAM)modes.Here,we demonstrate the eff...The mode sorter is the crucial component of the communication systems based on orbital angular momentum(OAM).However,schemes proposed so far can only effectively sort integer OAM(IOAM)modes.Here,we demonstrate the effective sorting of fractional OAM(FOAM)modes by utilizing the coordinate transformation method,which can convert FOAM modes to IOAM modes.The transformed IOAM modes are subsequently sorted using a mode conversion method called topological charge matching.The validation of our scheme is verified by implementing two FOAM sorting processes and corresponding mode purity analyses,both theoretically and experimentally.This new sorting method exhibits great potential for implementing a highly confidential and high-capacity FOAM-based communication and data storage system,which may inspire further applications in both classical and quantum regimes.展开更多
Hydrogen has been recently utilized in many fields due to its recyclability and non-pollution characteristics.Hydrogen fuel cell vehicles and hydrogen refueling stations have become the main carrier of hydrogen energy...Hydrogen has been recently utilized in many fields due to its recyclability and non-pollution characteristics.Hydrogen fuel cell vehicles and hydrogen refueling stations have become the main carrier of hydrogen energy application.However,due to the inflammable and explosive characteristics,the safety problems of hydrogen became indispensable.This paper introduces the safety problems and countermeasures of hydrogen fuel cell vehicles and hydrogen refueling stations.The research progress and achievements of hydrogen energy standards are then comprehensively discussed.Finally,the development status,existing problems and future development direction of five kinds of optical fiber sensors are pointed out.展开更多
The concept of synthetic dimensions has emerged as a powerful framework in photonics and atomic physics,enabling the exploration of high-dimensional physics beyond conventional spatial constraints.Originally developed...The concept of synthetic dimensions has emerged as a powerful framework in photonics and atomic physics,enabling the exploration of high-dimensional physics beyond conventional spatial constraints.Originally developed for quantum simulations in high dimensions,synthetic dimensions have since demonstrated advantages in designing novel Hamiltonians and manipulating quantum or optical states for exploring topological physics,and for applications in computing and information processing.Here,we provide a comprehensive overview of progress in synthetic dimensions across photonic,atomic,and other physical platforms over the past decade.We showcase different approaches used to construct synthetic dimensions and highlight key physical phenomena enabled by the advantage of such a framework.By offering a unified perspective on developments in this field,we aim to provide insights into how synthetic dimensions can bridge fundamental physics and applied technologies,fostering interdisciplinary engagement in quantum simulation,atomic and photonic engineering,and information processing.展开更多
Non-Hermitian topological photonics plays a key role in bridging topological matter with gain and loss engineering in optics.Here we report the experimental observation of the break of chiral currents in a Hall ladder...Non-Hermitian topological photonics plays a key role in bridging topological matter with gain and loss engineering in optics.Here we report the experimental observation of the break of chiral currents in a Hall ladder from the non-Hermiticity by constructing synthetic frequency dimension in two rings,where currents on both legs of the ladder co-propagate in the same direction.The origin of such phenomena is resulted from the interplay between the effective magnetic flux and the on-site gain and loss.Such non-Hermitian co-propagating currents exhibit characteristics of unidirectional frequency conversion in both rings,and moreover,different from the counterpart in Hermitian systems,can provide a method to probe the signatures of the non-Hermitian skin effect from steady-state bulk dynamics.Our model is further extended to models including next-nearest-neighbor couplings,pointing to a way for observing the non-Hermitian signature with higher winding number,and provides a new control knob for light manipulation with the topological dissipation engineering.展开更多
Traditional technologies for manufacturing microfluidic devices often involve the use of molds for polydimethylsiloxane(PDMS)casting generated from photolithography techniques,which are time-consuming,costly,and diffi...Traditional technologies for manufacturing microfluidic devices often involve the use of molds for polydimethylsiloxane(PDMS)casting generated from photolithography techniques,which are time-consuming,costly,and difficult to use in generating multilayered structure.As an alternative,3D printing allows rapid and cost-effective prototyping and customization of complex microfluidic structures.However,3Dprinted devices are typically opaque and are challenging to create small channels.Herein,we introduce a novel“programmable optical window bonding”3D printing method that incorporates the bonding of an optical window during the printing process,facilitating the fabrication of transparent microfluidic devices with high printing fidelity.Our approach allows direct and rapid manufacturing of complex microfluidic structure without the use of molds for PDMS casting.We successfully demonstrated the applications of this method by fabricating a variety of microfluidic devices,including perfusable chips for cell culture,droplet generators for spheroid formation,and high-resolution droplet microfluidic devices involving different channel width and height for rapid antibiotic susceptibility testing.Overall,our 3D printing method demonstrates a rapid and cost-effective approach for manufacturing microfluidic devices,particularly in the biomedical field,where rapid prototyping and high-quality optical analysis are crucial.展开更多
Spatial photonic Ising machines(SPIMs)are promising computation devices that can be used to find the ground states of different spin Hamiltonians and solve large-scale optimization problems.The photonic architecture l...Spatial photonic Ising machines(SPIMs)are promising computation devices that can be used to find the ground states of different spin Hamiltonians and solve large-scale optimization problems.The photonic architecture leverages the matrix multiplexing ability of light to accelerate the computing of spin Hamiltonian via free space light transform.However,the intrinsic long-range nature of spatial light only allows for uncontrolled all-to-all spin interaction.We explore the ability to establish arbitrary spin Hamiltonian by modulating the momentum of light.Arbitrary displacement-dependent spin interactions can be computed from different momenta of light,formulating as a generalized Plancherel theorem,which allows us to implement a SPIM with a minimal optical operation(that is,a single Fourier transform)to obtain the Hamiltonian of customized spin interaction.Experimentally,we unveil the exotic magnetic phase diagram of the generalized J_(1)-J_(2)-J_(3)model,shedding light on the ab initio magnetic states of iron chalcogenides.Moreover,we observe Berezinskii-Kosterlitz-Thouless dynamics by implementing an XY model.We open an avenue to controlling arbitrary spin interaction from the momentum space of light,offering a promising method for on-demand spin model simulation with a simple spatial light platform.展开更多
Transmission distance and number of users limit the realization of large-scale scalable quantum communication networks,as existing quantum network construction techniques struggle to address these two important factor...Transmission distance and number of users limit the realization of large-scale scalable quantum communication networks,as existing quantum network construction techniques struggle to address these two important factors simultaneously.In this paper,we propose a long-distance large-scale and scalable fully-connected quantum secure direct communication(QSDC)network,which employs a double-pumped structure and the introduction of extra noise to successfully realize QSDC over 300 km between four users in the network in pairs.The results demonstrate that the fidelity of the entangled state shared between users following communication remains above 85%.The results of our research demonstrate the viability of this quantum communication network,offering a novel foundation for the future realization of long-distance large-scale quantum communication.展开更多
In quantum information processing,unitary transformations are oftentimes used to implement computing tasks.However,unitary transformations are not enough for all situations.Therefore,it is important to explore non-uni...In quantum information processing,unitary transformations are oftentimes used to implement computing tasks.However,unitary transformations are not enough for all situations.Therefore,it is important to explore non-unitary transformations in quantum computing and simulation.Here,we introduce non-unitary transformations by performing singular value decomposition(SVD)on two-photon interference.Through simulation,we show that losses modeled by non-unitary transformation can be perceived as variables to control two-photon interference continuously,and the coincidence statistics can be changed by an appropriate choice of observation basis.The results are promising in the design of integrated optical circuits,providing a way toward fabricating large-scale programmable circuits.展开更多
The commercialization of lithium niobate on insulator(LNOI) wafer has resulted in significant on-chip photonic integration application owing to its remarkable photonic,acousto-optic,electro-optic,and piezoelectric nat...The commercialization of lithium niobate on insulator(LNOI) wafer has resulted in significant on-chip photonic integration application owing to its remarkable photonic,acousto-optic,electro-optic,and piezoelectric nature.In recent years,a variety of high-performance on-chip LNOI-based photonic devices have been realized.In this study,we developed a 1-mol% erbium-doped lithium niobate crystal and its LNOI on a silicon substrate and fabricated an erbium-doped LNOI microdisk with high quality factor(~1.05×105).C-band laser emission at ~1530 and ~1560 nm(linewidth 0.12 nm) from the high-Q erbium-doped LNOI microdisk was demonstrated with 974-and 1460-nm pumping,with the latter having better thermal stability.This microlaser would play an important role in the photonic integrated circuits of the lithium niobate platform.展开更多
Quantum secure direct communication(QSDC)based on entanglement can directly transmit confidential information.However,the inability to simultaneously distinguish the four sets of encoded entangled states limits its pr...Quantum secure direct communication(QSDC)based on entanglement can directly transmit confidential information.However,the inability to simultaneously distinguish the four sets of encoded entangled states limits its practical application.Here,we explore a QSDC network based on time–energy entanglement and sum-frequency generation.In total,15 users are in a fully connected QSDC network,and the fidelity of the entangled state shared by any two users is>97%.The results show that when any two users are performing QSDC over 40 km of optical fiber,the fidelity of the entangled state shared by them is still>95%,and the rate of information transmission can be maintained above 1 Kbp/s.Our result demonstrates the feasibility of a proposed QSDC network and hence lays the foundation for the realization of satellite-based long-distance and global QSDC in the future.展开更多
Scattering of waves, e.g., light, due to medium inhomogeneity is ubiquitous in physics and isconsidered detrimental for many applications. Wavefront shaping technology is a powerful tool to defeatscattering and focus ...Scattering of waves, e.g., light, due to medium inhomogeneity is ubiquitous in physics and isconsidered detrimental for many applications. Wavefront shaping technology is a powerful tool to defeatscattering and focus light through inhomogeneous media, which is vital for optical imaging, communication,therapy, etc. Wavefront shaping based on the scattering matrix (SM) is extremely useful in handling dynamicprocesses in the linear regime. However, the implementation of such a method for controlling light in nonlinearmedia is still a challenge and has been unexplored until now. We report a method to determine the SM ofnonlinear scattering media with second-order nonlinearity. We experimentally demonstrate its feasibility inwavefront control and realize focusing of nonlinear signals through strongly scattering quadratic media.Moreover, we show that statistical properties of this SM still follow the random matrix theory. The scattering-matrix approach of nonlinear scattering medium opens a path toward nonlinear signal recovery, nonlinearimaging, microscopic object tracking, and complex environment quantum information processing.展开更多
All-optical logic gates including AND, XOR, and NOT gates, as well as a half-adder, are realized based on twodimensional lithium niobate photonic crystal(PhC) circuits with Ph C micro-cavities.The proposed all-optical...All-optical logic gates including AND, XOR, and NOT gates, as well as a half-adder, are realized based on twodimensional lithium niobate photonic crystal(PhC) circuits with Ph C micro-cavities.The proposed all-optical devices have an extinction ratio as high as 23 dB due to the effective all-optical switch function induced by twomissing-hole micro-cavities.These proposed devices can have potential implementation of complex integrated optical functionalities including all-optical computing in a lithium niobate slab or thin film.展开更多
Future quantum information networks operated on telecom channels require qubit transfer between different wavelengths while preserving quantum coherence and entanglement. Qubit transfer is a nonlinear optical process,...Future quantum information networks operated on telecom channels require qubit transfer between different wavelengths while preserving quantum coherence and entanglement. Qubit transfer is a nonlinear optical process,but currently the types of atoms used for quantum information processing and storage are limited by the narrow bandwidth of upconversion available. Here we present the first experimental demonstration of broadband and high-efficiency quasi-phase matching second-harmonic generation(SHG) in a chip-scale periodically poled lithium niobate thin film. We achieve a large bandwidth of up to 2 THz for SHG by satisfying quasi-phase matching and group-velocity matching simultaneously. Furthermore, by changing the film thickness, the central wavelength of the quasi-phase matching SHG bandwidth can be modulated from 2.70 μm to 1.44 μm. The reconfigurable quasi-phase matching lithium niobate thin film provides a significant on-chip integrated platform for photonics and quantum optics.展开更多
Quantum coherence in quantum optics is an essential part of optical information processing and light manipulation.Alkali metal vapors,despite the numerous shortcomings,are traditionally used in quantum optics as a wor...Quantum coherence in quantum optics is an essential part of optical information processing and light manipulation.Alkali metal vapors,despite the numerous shortcomings,are traditionally used in quantum optics as a working medium due to convenient near-infrared excitation,strong dipole transitions and long-lived coherence.Here,we proposed and experimentally demonstrated photon retention and subsequent re-emittance with the quantum coherence in a system of coherently excited molecular nitrogen ions(N_(2)^(+))which are produced using a strong 800 nm femtosecond laser pulse.Such photon retention,facilitated by quantum coherence,keeps releasing directly-unmeasurable coherent photons for tens of picoseconds,but is able to be read out by a time-delayed femtosecond pulse centered at 1580 nm via two-photon resonant absorption,resulting in a strong radiation at 329.3 nm.We reveal a pivotal role of the excited-state population to transmit such extremely weak re-emitted photons in this system.This new finding unveils the nature of the coherent quantum control in N_(2)^(+)for the potential platform for optical information storage in the remote atmosphere,and facilitates further exploration of fundamental interactions in the quantum optical platform with strong-field ionized molecules.展开更多
基金financially supported by the National Basic Research Program of China (2009CB825105)the National Natural Science Foundation of China (41261090)
文摘Modeling soil salinity in an arid salt-affected ecosystem is a difficult task when using remote sensing data because of the complicated soil context （vegetation cover, moisture, surface roughness, and organic matter） and the weak spectral features of salinized soil. Therefore, an index such as the salinity index （SI） that only uses soil spectra may not detect soil salinity effectively and quantitatively. The use of vegetation reflectance as an indirect indicator can avoid limitations associated with the direct use of soil reflectance. The normalized difference vegetation index （NDVI）, as the most common vegetation index, was found to be responsive to salinity but may not be available for retrieving sparse vegetation due to its sensitivity to background soil in arid areas. Therefore, the arid fraction integrated index （AFⅡ） was created as supported by the spectral mixture analysis （SMA）, which is more appropriate for analyzing variations in vegetation cover （particularly halophytes） than NDVI in the study area. Using soil and vegetation separately for detecting salinity perhaps is not feasible. Then, we developed a new and operational model, the soil salinity detecting model （SDM） that combines AFⅡ and SI to quantitatively estimate the salt content in the surface soil. SDMs, including SDM1 and SDM2, were constructed through analyzing the spatial characteristics of soils with different salinization degree by integrating AFⅡ and SI using a scatterplot. The SDMs were then compared to the combined spectral response index （COSRI） from field measurements with respect to the soil salt content. The results indicate that the SDM values are highly correlated with soil salinity, in contrast to the performance of COSRI. Strong exponential relationships were observed between soil salinity and SDMs （R2〉0.86, RMSE〈6.86） compared to COSRI （R2=0.71, RMSE=16.21）. These results suggest that the feature space related to biophysical properties combined with AFII and SI can effectively provide information on soil salinity.
文摘The use of low-coherence light is expected to be one of the effective ways to suppress or even eliminate the laser–plasma instabilities that arise in attempts to achieve inertial confinement fusion.In this paper,a review of low-coherence high-power laser drivers and related key techniques is first presented.Work at typical low-coherence laser facilities,including Gekko XII,PHEBUS,Pharos III,and Kanal-2 is described.The many key techniques that are used in the research and development of low-coherence laser drivers are described and analyzed,including low-coherence source generation,amplification,harmonic conversion,and beam smoothing of low-coherence light.Then,recent progress achieved by our group in research on a broadband low-coherence laser driver is presented.During the development of our low-coherence high-power laser facility,we have proposed and implemented many key techniques for working with low-coherence light,including source generation,efficient amplification and propagation,harmonic conversion,beam smoothing,and precise beam control.Based on a series of technological breakthroughs,a kilojoule low-coherence laser driver named Kunwu with a coherence time of only 300 fs has been built,and the first round of physical experiments has been completed.This high-power laser facility provides not only a demonstration and verification platform for key techniques and system integration of a low-coherence laser driver,but also a new type of experimental platform for research into,for example,high-energy-density physics and,in particular,laser–plasma interactions.
基金The authors thank Professor Yongxiang Hu for the ns-LSP experiment on Mg-3Gd alloy and his useful discussion.The research was supported by the National Key R&D Program of China(2017YFA0303700)the National Natural Science Foundation of China(NSFC)(11574208).
基金the support of grants from the National Key R&D Program of China(Nos.2018YFA0108202 and 2017YFA0205300)the National Natural Science Foundation of China(Nos.61571429,61801464,61801465,and 81471748)+1 种基金the STS Project of the Chinese Academy of Sciences(NO.KFJ-STS-SCYD-120)the Science and Technology Commission of Shanghai Municipality(Nos.16410711800 and 14391901900)
文摘A simple,convenient,and highly sensitive bio-interface for graphene field-effect transistors(GFETs) based on multifunctional nano-denatured bovine serum albumin(nano-dBSA) functionalization was developed to target cancer bio-markers.The novel graphene–protein bioelectronic interface was constructed by heating to denature native BSA on the graphene substrate surface.The formed nano-d BSA film served as the cross-linker to immobilize monoclonal antibody against car-cinoembryonic antigen(anti-CEA mAb) on the graphene channel activated by EDC and Sulfo-NHS.The nano-dBSA film worked as a self-protecting layer of graphene to prevent surface contamination by lithographic processing.The improved GFETbiosensor exhibited good specificity and high sensitivity toward the target at an ultralow concentration of 337.58 fg mL-1.The electrical detection of the binding of CEA followed the Hill model for ligand–receptor interaction,indicating the negative binding cooperativity between CEA and anti-CEA mAb with a dissociation constant of 6.82×10-10M.The multifunctional nano-dBSA functionalization can confer a new function to graphene-like 2D nanomaterials and provide a promising bio-functionalization method for clinical application in biosensing,nanomedicine,and drug delivery.
基金supported by the National Key Research and Development Program of China(Grant Nos.2017YFA0303700 and 2018YFA0306301)the National Natural Science Foundation of China(Grant Nos.11734011,12004245,and 62105154)+3 种基金the Foundation for Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01-ZX06)the Shandong Quancheng Scholarship(Grant No.00242019024)the China Postdoctoral Science Foundation(Grant No.2021M691601)the Natural Science Foundation of Jiangsu Province(Grant No.BK20210324)。
文摘Perfect vector beams are a class of special vector beams with invariant radius and intensity profiles under changing topological charges.However,with the limitation of current devices,the generation of these vector beams is limited in the visible and infrared wavebands.Herein,we generate perfect vector beams in the ultraviolet region assisted by nonlinear frequency conversion.Experimental and simulation results show that the radius of the generated ultraviolet perfect vector beams remains invariant and is thus independent of the topological charge.Furthermore,we measure the power of the generated ultraviolet perfect vector beams with the change of their topological charges.This study provides an alternative approach to generating perfect vector beams for ultraviolet wavebands and may promote their application to optical trapping and optical communication.
基金supported by the China Postdoctoral Science Foundation(Grant Number 2023M742598).
文摘Stirred reactors are key equipment in production,and unpredictable failures will result in significant economic losses and safety issues.Therefore,it is necessary to monitor its health state.To achieve this goal,in this study,five states of the stirred reactor were firstly preset:normal,shaft bending,blade eccentricity,bearing wear,and bolt looseness.Vibration signals along x,y and z axes were collected and analyzed in both the time domain and frequency domain.Secondly,93 statistical features were extracted and evaluated by ReliefF,Maximal Information Coefficient(MIC)and XGBoost.The above evaluation results were then fused by D-S evidence theory to extract the final 16 features that are most relevant to the state of the stirred reactor.Finally,the CatBoost algorithm was introduced to establish the stirred reactor health monitoring model.The validation results showed that the model achieves 100%accuracy in detecting the fault/normal state of the stirred reactor and 98%accuracy in diagnosing the type of fault.
基金supported by the National Natural Science Foundation of China(Grant Nos.12192252 and 12374314)the National Key Research and Development Program of China(Grant No.2023YFA1407200).
文摘The mode sorter is the crucial component of the communication systems based on orbital angular momentum(OAM).However,schemes proposed so far can only effectively sort integer OAM(IOAM)modes.Here,we demonstrate the effective sorting of fractional OAM(FOAM)modes by utilizing the coordinate transformation method,which can convert FOAM modes to IOAM modes.The transformed IOAM modes are subsequently sorted using a mode conversion method called topological charge matching.The validation of our scheme is verified by implementing two FOAM sorting processes and corresponding mode purity analyses,both theoretically and experimentally.This new sorting method exhibits great potential for implementing a highly confidential and high-capacity FOAM-based communication and data storage system,which may inspire further applications in both classical and quantum regimes.
基金the National Key Research and Development Program of China(Grant No.2021YFB4000902)the Key Research and Development Project of Hubei Province(Grant No.2021BCA216)are both highly appreciated。
文摘Hydrogen has been recently utilized in many fields due to its recyclability and non-pollution characteristics.Hydrogen fuel cell vehicles and hydrogen refueling stations have become the main carrier of hydrogen energy application.However,due to the inflammable and explosive characteristics,the safety problems of hydrogen became indispensable.This paper introduces the safety problems and countermeasures of hydrogen fuel cell vehicles and hydrogen refueling stations.The research progress and achievements of hydrogen energy standards are then comprehensively discussed.Finally,the development status,existing problems and future development direction of five kinds of optical fiber sensors are pointed out.
基金supported by the National Natural Science Foundation of China(Nos.12122407,12204304,12104297,12192252,and 12204233)the National Key Research and Development Program of China(No.2023YFA1407200)+1 种基金support from the National Science Foundation(No.1945031)the AFOSR MURI Program(No.FA9550-22-1-0339).
文摘The concept of synthetic dimensions has emerged as a powerful framework in photonics and atomic physics,enabling the exploration of high-dimensional physics beyond conventional spatial constraints.Originally developed for quantum simulations in high dimensions,synthetic dimensions have since demonstrated advantages in designing novel Hamiltonians and manipulating quantum or optical states for exploring topological physics,and for applications in computing and information processing.Here,we provide a comprehensive overview of progress in synthetic dimensions across photonic,atomic,and other physical platforms over the past decade.We showcase different approaches used to construct synthetic dimensions and highlight key physical phenomena enabled by the advantage of such a framework.By offering a unified perspective on developments in this field,we aim to provide insights into how synthetic dimensions can bridge fundamental physics and applied technologies,fostering interdisciplinary engagement in quantum simulation,atomic and photonic engineering,and information processing.
基金supported by National Key R&D Program of China(No.2023YFA1407200 and No.2021YFA1400900)National Natural Science Foundation of China(12122407,12104297,12192252,11974245,and 12204304)China Postdoctoral Science Foundation(2023M742292,GZC20231614).
文摘Non-Hermitian topological photonics plays a key role in bridging topological matter with gain and loss engineering in optics.Here we report the experimental observation of the break of chiral currents in a Hall ladder from the non-Hermiticity by constructing synthetic frequency dimension in two rings,where currents on both legs of the ladder co-propagate in the same direction.The origin of such phenomena is resulted from the interplay between the effective magnetic flux and the on-site gain and loss.Such non-Hermitian co-propagating currents exhibit characteristics of unidirectional frequency conversion in both rings,and moreover,different from the counterpart in Hermitian systems,can provide a method to probe the signatures of the non-Hermitian skin effect from steady-state bulk dynamics.Our model is further extended to models including next-nearest-neighbor couplings,pointing to a way for observing the non-Hermitian signature with higher winding number,and provides a new control knob for light manipulation with the topological dissipation engineering.
文摘Traditional technologies for manufacturing microfluidic devices often involve the use of molds for polydimethylsiloxane(PDMS)casting generated from photolithography techniques,which are time-consuming,costly,and difficult to use in generating multilayered structure.As an alternative,3D printing allows rapid and cost-effective prototyping and customization of complex microfluidic structures.However,3Dprinted devices are typically opaque and are challenging to create small channels.Herein,we introduce a novel“programmable optical window bonding”3D printing method that incorporates the bonding of an optical window during the printing process,facilitating the fabrication of transparent microfluidic devices with high printing fidelity.Our approach allows direct and rapid manufacturing of complex microfluidic structure without the use of molds for PDMS casting.We successfully demonstrated the applications of this method by fabricating a variety of microfluidic devices,including perfusable chips for cell culture,droplet generators for spheroid formation,and high-resolution droplet microfluidic devices involving different channel width and height for rapid antibiotic susceptibility testing.Overall,our 3D printing method demonstrates a rapid and cost-effective approach for manufacturing microfluidic devices,particularly in the biomedical field,where rapid prototyping and high-quality optical analysis are crucial.
基金the financial support from the National Key Research and Development Program of China(Grant No.2022YFA1205100)National Natural Science Foundation of China(Grant Nos.12122407,12192252,and 12274296)+3 种基金Shanghai International Cooperation Program for Science and Technology(Grant No.22520714300)Shanghai Jiao Tong University 2030 Initiativesponsored by the Yangyang Development Fundfinancial support from the Israel Science Foundation(Grant No.1170/20)。
文摘Spatial photonic Ising machines(SPIMs)are promising computation devices that can be used to find the ground states of different spin Hamiltonians and solve large-scale optimization problems.The photonic architecture leverages the matrix multiplexing ability of light to accelerate the computing of spin Hamiltonian via free space light transform.However,the intrinsic long-range nature of spatial light only allows for uncontrolled all-to-all spin interaction.We explore the ability to establish arbitrary spin Hamiltonian by modulating the momentum of light.Arbitrary displacement-dependent spin interactions can be computed from different momenta of light,formulating as a generalized Plancherel theorem,which allows us to implement a SPIM with a minimal optical operation(that is,a single Fourier transform)to obtain the Hamiltonian of customized spin interaction.Experimentally,we unveil the exotic magnetic phase diagram of the generalized J_(1)-J_(2)-J_(3)model,shedding light on the ab initio magnetic states of iron chalcogenides.Moreover,we observe Berezinskii-Kosterlitz-Thouless dynamics by implementing an XY model.We open an avenue to controlling arbitrary spin interaction from the momentum space of light,offering a promising method for on-demand spin model simulation with a simple spatial light platform.
基金supported in part by the National Natural Science Foundation of China(12074155,62375164,and 12192252)the Shuguang Program of Shanghai Education Development Foundation and Shanghai Municipal Education Commission(24SG53)+2 种基金the Guangdong Provincial Quantum Science Strategic Initiative(GDZX2403003)the Foundation for Shanghai Municipal Science and Technology Major Project(2019SHZDZX01-ZX06)SJTU(21X010200828)。
文摘Transmission distance and number of users limit the realization of large-scale scalable quantum communication networks,as existing quantum network construction techniques struggle to address these two important factors simultaneously.In this paper,we propose a long-distance large-scale and scalable fully-connected quantum secure direct communication(QSDC)network,which employs a double-pumped structure and the introduction of extra noise to successfully realize QSDC over 300 km between four users in the network in pairs.The results demonstrate that the fidelity of the entangled state shared between users following communication remains above 85%.The results of our research demonstrate the viability of this quantum communication network,offering a novel foundation for the future realization of long-distance large-scale quantum communication.
基金supported by the National Natural Science Foundation of China(Nos.12074155,62375164,and 12192252)the Foundation for Shanghai Municipal Science and Technology Major Project(No.2019SHZDZX01-ZX06)+1 种基金the SJTU(No.21×010200828)the Innovation Programme for Quantum Science and Technology(No.2021ZD0300802)。
文摘In quantum information processing,unitary transformations are oftentimes used to implement computing tasks.However,unitary transformations are not enough for all situations.Therefore,it is important to explore non-unitary transformations in quantum computing and simulation.Here,we introduce non-unitary transformations by performing singular value decomposition(SVD)on two-photon interference.Through simulation,we show that losses modeled by non-unitary transformation can be perceived as variables to control two-photon interference continuously,and the coincidence statistics can be changed by an appropriate choice of observation basis.The results are promising in the design of integrated optical circuits,providing a way toward fabricating large-scale programmable circuits.
基金supported by the National Key R&D Program of China (Grant Nos. 2019YFB2203500, and 2017YFA0303700)the National Natural Science Foundation of China (Grant No. 91950107)the Foundation for Development of Science and Technology of Shanghai (Grant No. 17JC1400400)。
文摘The commercialization of lithium niobate on insulator(LNOI) wafer has resulted in significant on-chip photonic integration application owing to its remarkable photonic,acousto-optic,electro-optic,and piezoelectric nature.In recent years,a variety of high-performance on-chip LNOI-based photonic devices have been realized.In this study,we developed a 1-mol% erbium-doped lithium niobate crystal and its LNOI on a silicon substrate and fabricated an erbium-doped LNOI microdisk with high quality factor(~1.05×105).C-band laser emission at ~1530 and ~1560 nm(linewidth 0.12 nm) from the high-Q erbium-doped LNOI microdisk was demonstrated with 974-and 1460-nm pumping,with the latter having better thermal stability.This microlaser would play an important role in the photonic integrated circuits of the lithium niobate platform.
基金This work is supported in part by the National Key Research and Development Program of China(Grant No.2017YFA0303700)National Natural Science Foundation of China(Grant Nos.11734011,11804135,and 12074155)+1 种基金The Foundation for Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01-ZX06)Project funded by China Postdoctoral Science Foundation(Grant No.2019M661476).
文摘Quantum secure direct communication(QSDC)based on entanglement can directly transmit confidential information.However,the inability to simultaneously distinguish the four sets of encoded entangled states limits its practical application.Here,we explore a QSDC network based on time–energy entanglement and sum-frequency generation.In total,15 users are in a fully connected QSDC network,and the fidelity of the entangled state shared by any two users is>97%.The results show that when any two users are performing QSDC over 40 km of optical fiber,the fidelity of the entangled state shared by them is still>95%,and the rate of information transmission can be maintained above 1 Kbp/s.Our result demonstrates the feasibility of a proposed QSDC network and hence lays the foundation for the realization of satellite-based long-distance and global QSDC in the future.
基金supported in part by the National Key R&D Program of China (No. 2018YFA0306301)the National Natural Science Foundation of China (Nos. 12192252, 62022058, 12074252, and 12004245)+2 种基金the Shanghai Municipal Science and Technology Major Project (No. 2019SHZDZX01ZX06)the Shanghai Rising-Star Program (No. 20QA1405400)the Yangyang Development Fund.
文摘Scattering of waves, e.g., light, due to medium inhomogeneity is ubiquitous in physics and isconsidered detrimental for many applications. Wavefront shaping technology is a powerful tool to defeatscattering and focus light through inhomogeneous media, which is vital for optical imaging, communication,therapy, etc. Wavefront shaping based on the scattering matrix (SM) is extremely useful in handling dynamicprocesses in the linear regime. However, the implementation of such a method for controlling light in nonlinearmedia is still a challenge and has been unexplored until now. We report a method to determine the SM ofnonlinear scattering media with second-order nonlinearity. We experimentally demonstrate its feasibility inwavefront control and realize focusing of nonlinear signals through strongly scattering quadratic media.Moreover, we show that statistical properties of this SM still follow the random matrix theory. The scattering-matrix approach of nonlinear scattering medium opens a path toward nonlinear signal recovery, nonlinearimaging, microscopic object tracking, and complex environment quantum information processing.
基金supported by the National Key R&D Program of China(No.2017YFA0303700)the National Natural Science Foundation of China(NFSC)(No.11574208)
文摘All-optical logic gates including AND, XOR, and NOT gates, as well as a half-adder, are realized based on twodimensional lithium niobate photonic crystal(PhC) circuits with Ph C micro-cavities.The proposed all-optical devices have an extinction ratio as high as 23 dB due to the effective all-optical switch function induced by twomissing-hole micro-cavities.These proposed devices can have potential implementation of complex integrated optical functionalities including all-optical computing in a lithium niobate slab or thin film.
基金National Key R&D Program of China(2017YFA0303700)National Natural Science Foundation of China(NSFC)(11574208)
文摘Future quantum information networks operated on telecom channels require qubit transfer between different wavelengths while preserving quantum coherence and entanglement. Qubit transfer is a nonlinear optical process,but currently the types of atoms used for quantum information processing and storage are limited by the narrow bandwidth of upconversion available. Here we present the first experimental demonstration of broadband and high-efficiency quasi-phase matching second-harmonic generation(SHG) in a chip-scale periodically poled lithium niobate thin film. We achieve a large bandwidth of up to 2 THz for SHG by satisfying quasi-phase matching and group-velocity matching simultaneously. Furthermore, by changing the film thickness, the central wavelength of the quasi-phase matching SHG bandwidth can be modulated from 2.70 μm to 1.44 μm. The reconfigurable quasi-phase matching lithium niobate thin film provides a significant on-chip integrated platform for photonics and quantum optics.
基金the National Natural Science Foundation of China(11822410,12034013,11734009,and 11974245)the National Key R&D Program of China(2017YFA0303701 and 2019YFA0705000)+10 种基金the Shanghai Municipal Science and Technology Major Project(2019SHZDZX01)the Program of Shanghai Academic Research Leader(20XD1424200)the Natural Science Foundation of Shanghai(19ZR1475700)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB16030300)the Key Research Program of Frontier Sciences of Chinese Academy of Sciences(QYZDJ-SSW-SLH010)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2018284)NSF(ECCS-1509268,and CMMI-1826078)AFOSR(FA9550-20-1-0366)partially supported by the Fundamental Research Funds for the Central Universitiesthe support from the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learningthe support from Shandong Quancheng Scholarship(00242019024)。
文摘Quantum coherence in quantum optics is an essential part of optical information processing and light manipulation.Alkali metal vapors,despite the numerous shortcomings,are traditionally used in quantum optics as a working medium due to convenient near-infrared excitation,strong dipole transitions and long-lived coherence.Here,we proposed and experimentally demonstrated photon retention and subsequent re-emittance with the quantum coherence in a system of coherently excited molecular nitrogen ions(N_(2)^(+))which are produced using a strong 800 nm femtosecond laser pulse.Such photon retention,facilitated by quantum coherence,keeps releasing directly-unmeasurable coherent photons for tens of picoseconds,but is able to be read out by a time-delayed femtosecond pulse centered at 1580 nm via two-photon resonant absorption,resulting in a strong radiation at 329.3 nm.We reveal a pivotal role of the excited-state population to transmit such extremely weak re-emitted photons in this system.This new finding unveils the nature of the coherent quantum control in N_(2)^(+)for the potential platform for optical information storage in the remote atmosphere,and facilitates further exploration of fundamental interactions in the quantum optical platform with strong-field ionized molecules.
