High-resolution seeing through complex scattering media such as turbid water,biological tissues,and mist is a significant challenge because the strong scattering scrambles the light paths and forms the scattering wall...High-resolution seeing through complex scattering media such as turbid water,biological tissues,and mist is a significant challenge because the strong scattering scrambles the light paths and forms the scattering wall.We propose an active polarized iterative optimization approach for high-resolution imaging through complex scattering media.By acquiring a series of sub-polarized images,we can capture the diverse pattern-illuminated images with various high-frequency component information caused by the Brownian motion of complex scattering materials,which are processed using the common-mode rejection of polarization characteristics to extract target information from scattering medium information.Following that,our computational reconstruction technique employs an iterative optimization algorithm that commences with patternilluminated Fourier ptychography for reconstructing the high-resolution scene.It is extremely important that our approach for high-resolution imaging through complex scattering media is not limited by priori information and optical memory effect.The proposed approach is suitable for not only dynamic but also static scattering media,which may find applications in the biomedicine field,such as skin abnormalities,non-invasive blood flow,and superficial tumors.展开更多
Glucose molecules are of great significance being one of the most important molecules in metabolic chain.However,due to the small Raman scattering cross-section and weak/non-adsorption on bare metals,accurately obtain...Glucose molecules are of great significance being one of the most important molecules in metabolic chain.However,due to the small Raman scattering cross-section and weak/non-adsorption on bare metals,accurately obtaining their"fingerprint information"remains a huge obstacle.Herein,we developed a tip-enhanced Raman scattering(TERS)technique to address this challenge.Adopting an optical fiber radial vector mode internally illuminates the plasmonic fiber tip to effectively suppress the background noise while generating a strong electric-field enhanced tip hotspot.Furthermore,the tip hotspot approaching the glucose molecules was manipulated via the shear-force feedback to provide more freedom for selecting substrates.Consequently,our TERS technique achieves the visualization of all Raman modes of glucose molecules within spectral window of 400-3200 cm^(-1),which is not achievable through the far-field/surface-enhanced Raman,or the existing TERS techniques.Our TERS technique offers a powerful tool for accurately identifying Raman scattering of molecules,paving the way for biomolecular analysis.展开更多
We investigate theoretically the enhancement of mechanical squeezing in a multimode optomechanical system by introducing a coherent phonon–photon interaction via the backward stimulated Brillouin scattering(BSBS)proc...We investigate theoretically the enhancement of mechanical squeezing in a multimode optomechanical system by introducing a coherent phonon–photon interaction via the backward stimulated Brillouin scattering(BSBS)process.The coherent photon–phonon interaction where two optical modes couple to a Brillouin acoustic mode with a large decay rate provides an extra channel for the cooling of a Duffing mechanical oscillator.The squeezing degree and the robustness to the thermal noises of the Duffing mechanical mode can be enhanced greatly.When the Duffing nonlinearity is weak,the squeezing degree of the mechanical mode in the presence of BSBS can be improved by more than one order of magnitude compared with that in the absence of BSBS.Our scheme may be extended to other quantum systems to study novel quantum effects.展开更多
In this study,we developed a single-beam optical trap-based surface-enhanced Raman scattering(SERS)optofluidic molecular fingerprint spectroscopy detection system.This system utilizes a single-beam optical trap to con...In this study,we developed a single-beam optical trap-based surface-enhanced Raman scattering(SERS)optofluidic molecular fingerprint spectroscopy detection system.This system utilizes a single-beam optical trap to concentrate free silver nanoparticles(AgNPs)within an optofluidic chip,significantly enhancing SERS performance.We investigated the optical field distribution characteristics within the tapered fiber using COMSOL simulation software and established a MATLAB simulation model to validate the single-beam optical trap's effectiveness in capturing AgNPs,demonstrating the theoretical feasibility of our approach.To verify the particle capture efficacy of the system,we experimentally controlled the optical trap's on-off state to manage the capture and release of particles precisely.The experimental results indicated that the Raman signal intensity in the capture state was significantly higher than in the non-capture state,confirming that the single-beam optical trap effectively enhances the SERS detection capability of the optofluidic detection system.Furthermore,we employed Raman mapping techniques to investigate the impact of the capture area on the SERS effect,revealing that the spectral intensity of molecular fingerprints in the laser-trapping region is significantly improved.We successfully detected the Raman spectrum of crystal violet at a concentration of 10^(−9)mol/L and pesticide thiram at a concentration of 10^(−5)mol/L,further demonstrating the ability of the single-beam optical trap in enhancing the molecular fingerprint spectrum identification capability of the SERS optofluidic chips.The optical trapping SERS optofluidic detection system developed in this study,as a key component of an integrated optoelectronic sensing system,holds the potential for integration with portable high-power lasers and high-performance Raman spectrometers.This integration is expected to advance highly integrated technologies and significantly enhance the overall performance and portability of optoelectronic sensing systems.展开更多
Accurate satellite data assimilation under all-sky conditions requires enhanced parameterization of scattering properties for frozen hydrometeors in clouds.This study aims to develop a nonspherical scattering look-up ...Accurate satellite data assimilation under all-sky conditions requires enhanced parameterization of scattering properties for frozen hydrometeors in clouds.This study aims to develop a nonspherical scattering look-up table that contains the optical properties of five hydrometeor types—rain,cloud water,cloud ice,graupel,and snow—for the Advanced Radiative Transfer Modeling System(ARMS)at frequencies below 220 GHz.The discrete dipole approximation(DDA)method is employed to compute the single-scattering properties of solid cloud particles,modeling these particles as aggregated roughened bullet rosettes.The bulk optical properties of the cloud layer are derived by integrating the singlescattering properties with a modified Gamma size distribution,specifically for distributions with 18 effective radii.The bulk phase function is then projected onto a series of generalized spherical functions,applying the delta-M method for truncation.The results indicate that simulations using the newly developed nonspherical scattering look-up table exhibit significant consistency with observations under deep convection conditions.In contrast,assuming spherical solid cloud particles leads to excessive scattering at mid-frequency channels and insufficient scattering at high-frequency channels.This improvement in radiative transfer simulation accuracy for cloudy conditions will better support the assimilation of allsky microwave observations into numerical weather prediction models.·Frozen cloud particles were modeled as aggregates of bullet rosettes and the optical properties at microwave range were computed by DDA.·A complete process and technical details for constructing a look-up table of ARMS are provided.·The ARMS simulations generally show agreement with observations of MWTS and MWHS under typhoon conditions using the new look-up table.展开更多
Quantitative detection of trace small-sized nanoplastics(<100 nm)remains a significant challenge in surface-enhanced Raman scattering(SERS).To tackle this issue,we developed a hydrophobic CuO@Ag nanowire substrate ...Quantitative detection of trace small-sized nanoplastics(<100 nm)remains a significant challenge in surface-enhanced Raman scattering(SERS).To tackle this issue,we developed a hydrophobic CuO@Ag nanowire substrate and introduced a multiplex-feature analysis strategy based on the coffee ring effect.This substrate not only offers high Raman enhancement but also exhibits a high probability of detection(POD),enabling rapid and accurate identification of 50 nm polystyrene nanoplastics over a broad concentration range(1–10−10 wt%).Importantly,experimental results reveal a strong correlation between the coffee ring formation and the concentration of nanoplastic dispersion.By incorporating Raman signal intensity,coffee ring diameter,and POD as combined features,we established a machine learning-based mapping between nanoplastic concentration and coffee ring characteristics,allowing precise predictions of dispersion concentration.The mean squared error of these predictions is remarkably low,ranging from 0.21 to 0.54,representing a 19 fold improvement in accuracy compared to traditional linear regression-based methods.This strategy effectively integrates SERS with wettability modification techniques,ensuring high sensitivity and fingerprinting capabilities,while addressing the limitations of Raman signal intensity in accurately reflecting concentration changes at ultra-low levels,providing a new idea for precise SERS measurements of nanoplastics.展开更多
Passive imaging through intense atmospheric scattering is a critical yet formidable challenge in optical imaging,with profound implications across various applications.Conventional cameras struggle under severe scatte...Passive imaging through intense atmospheric scattering is a critical yet formidable challenge in optical imaging,with profound implications across various applications.Conventional cameras struggle under severe scattering conditions,fundamentally limiting their effectiveness.We propose a groundbreaking directional atmospheric scattering model that revolutionizes passive imaging capabilities,converting a conventional camera to a super-camera.The model precisely characterizes directional photon propagation through scattering media,transforming this historically ill-posed problem into a well-posed solution,based on which a 4D spatial-angular scattering reconstruction method is proposed,which leverages both ballistic photons and directionally resolved scattered light,without relying on any scene-specific priors,to achieve unprecedented passive imaging performance enabling color imaging through over 12 transport mean free paths at distances up to 1.76 km.Our system recovers targets contributing as little as 0.00016%of the total detected signal,enhancing a standard camera’s signal recovery capacity by nearly 200×.To validate our approach,we introduce the first-ever real-world multiperspective scattering dataset,providing a critical benchmark for future research.We mark a paradigm shift in passive imaging,offering transformative potential for real-world applications under extreme atmospheric scattering conditions.展开更多
Gas targets have been used to measure the scattering length in neutron-proton(n-p)scattering experiments.Changes in electron dynamics within the gas target have a negligible effect on the dynamics of nucleons.However,...Gas targets have been used to measure the scattering length in neutron-proton(n-p)scattering experiments.Changes in electron dynamics within the gas target have a negligible effect on the dynamics of nucleons.However,electron dynamics are sensitively related to the specific form of the n-p interaction during the scattering process.We propose a theoretical approach to explore electron dynamics and determine the parameters of the n-p interaction.This approach is based on a three-body scattering process involving a neutron,a proton and an electron.Numerical results indicate significant differences in electron dynamics with varying values of n-p interaction parameters,providing additional information beyond scattering cross-sections to accurately determine these parameters.展开更多
The mechanisms of enhancing spin-orbit torque(SOT) have attracted significant attention, particularly regarding the influence of extrinsic scattering mechanisms on SOT efficiency, as they complement intrinsic contribu...The mechanisms of enhancing spin-orbit torque(SOT) have attracted significant attention, particularly regarding the influence of extrinsic scattering mechanisms on SOT efficiency, as they complement intrinsic contributions. In multilayer systems, extrinsic interfacial scattering, along with scattering from defects or impurities inside the materials, plays a crucial role in affecting the SOT efficiency. In this study, we successfully fabricated high-quality epitaxially grown [Ir/Pt]N superlattices with an increasing number of interfaces using a magnetron sputtering system to investigate the contribution of extrinsic interfacial scattering to SOT efficiency. We measured SOT efficiency through spin-torque ferromagnetic resonance methods and determined the spin Hall angle using the spin pumping technique. Additionally, we calculated spin transparency based on the SOT efficiency and spin Hall angle. Our findings indicate that the values of SOT efficiency, spin Hall angle, and spin transparency are enhanced in the superlattice structure compared to Pt, which we attribute to the increase in interfacial scattering.This research offers an effective strategy for designing and fabricating advanced spintronic devices.展开更多
Transforming a scattering medium into a lens for imaging very simple binary objects is possible;however,it remains challenging to image complex grayscale objects,let alone measure 3D continuous distribution objects.He...Transforming a scattering medium into a lens for imaging very simple binary objects is possible;however,it remains challenging to image complex grayscale objects,let alone measure 3D continuous distribution objects.Here,we propose and demonstrate the use of a ground glass diffuser as a scattering lens for imaging complex grayscale fringes,and we employ it to achieve microscopic structured light 3D imaging(MSL3DI).The ubiquitous property of the speckle patterns permits the exploitation of the scattering medium as an ultra-thin scattering lens with a variable focal length and a flexible working distance for microscale object measurement.The method provides a light,flexible,and cost-effective imaging device as an alternative to microscope objectives or telecentric lenses in conventional MSL3DI systems.We experimentally demonstrate that employing a scattering lens allows us to achieve relatively good phase information and robust 3D imaging from depth measurements,yielding measurement accuracy only marginally lower than that of a telecentric lens,typically within approximately 10μm.Furthermore,the scattering lens demonstrates robust performance even when the imaging distance exceeds the typical working distance of a telecentric lens.The proposed method facilitates the application of scattering imaging techniques,providing a more flexible solution for MSL3DI.展开更多
We present experimental results on kilojoule ultraviolet laser output with 1%spectral broadening.Through stimulated rotational Raman scattering(SRRS)with signal laser injection,we achieve effective spectral broadening...We present experimental results on kilojoule ultraviolet laser output with 1%spectral broadening.Through stimulated rotational Raman scattering(SRRS)with signal laser injection,we achieve effective spectral broadening in short-range propagation,with good retention of the original near-field distribution and time waveform.Theoretical calculations show that 2%bandwidth spectral broadening can be achieved by injecting 20 kW/cm^(2) signal light at 2.2 GW/cm^(2) flux of the pump laser.In addition,high-frequency modulation in the near field can be effectively avoided through replacement of the original random noise signal light by the controllable signal light.The SRRS in the atmospheric environment excited with signal laser injection can provide wide-band light output with controllable beam quality without long-distance propagation,representing an important potential route to realization of broadband laser drivers.展开更多
Extreme ultraviolet(EUV)lithography is crucial for advancing semiconductor manufacturing;however,current EUV light sources,such as laser-produced plasma(LPP),have significant limitations,including low energy-conversio...Extreme ultraviolet(EUV)lithography is crucial for advancing semiconductor manufacturing;however,current EUV light sources,such as laser-produced plasma(LPP),have significant limitations,including low energy-conversion efficiency and debris contamination.Various schemes,including optical free-electron laser undulators,have been studied to generate coherent EUV light.However,optical undulators suffer from limited focal lengths,which pose a significant challenge to achieving a higher gain.In this study,a novel approach is proposed that employs a stretched off-axis paraboloid(sOAP)mirror,thus extending the focus distance to the centimeter range while achieving a well-controlled periodic light field.This enables high-intensity 92-eV EUV sources to exceed 1016/s,as demonstrated in the simulations.The proposed setup provides an efficient and powerful solution for advanced applications including semiconductor lithography.展开更多
The quasiparticle scattering processes of the topological surface state(TSS)in three-dimensional topological insulators(TIs)have a vital effect on the many-body interactions and potential applications of topological m...The quasiparticle scattering processes of the topological surface state(TSS)in three-dimensional topological insulators(TIs)have a vital effect on the many-body interactions and potential applications of topological materials.In this study,we performed high-resolution temperature-dependent angle-resolved photoemission spectroscopy analysis of the 3D strong TI Bi_(2)Se_(3).Using an ab initio simulation,we analyzed the temperature dependence of the electronic structure and lifetime broadening of the TSS,which are closely associated with the quasiparticle scattering process,i.e.,electron–phonon coupling and spin-dependent scattering.We show that,at a low temperature(7 K),the spin-dependent electron scattering facilitates the anisotropic scattering rate of the TSS.Conversely,at room temperature(300 K),the electron–phonon coupling dominates the contribution to the scattering rate.The scattering rate increases with temperature and becomes uniform in momentum space owing to the temperature dependence of quasiparticle scattering.The quantitative study of temperature-dependent scattering rates in TSS is crucial to understanding the topological property and transport mobility of Dirac fermions for fundamental studies and potential applications.展开更多
In this paper,we present some properties of scattering data for the derivative nonlinear Schrödinger equation in H^(S)(R)(s≥1/2)starting from the Lax pair.We show that the reciprocal of the transmission coeffici...In this paper,we present some properties of scattering data for the derivative nonlinear Schrödinger equation in H^(S)(R)(s≥1/2)starting from the Lax pair.We show that the reciprocal of the transmission coefficient can be expressed as the sum of some iterative integrals,and its logarithm can be written as the sum of some connected iterative integrals.We provide the asymptotic properties of the first few iterative integrals of the reciprocal of the transmission coefficient.Moreover,we provide some regularity properties of the reciprocal of the transmission coefficient related to scattering data in H^(S)(R).展开更多
The study of collision between metastable positronium(Ps)and antihydrogen(H)is crucial for precision experiments involving H.In this paper,we investigate the elastic scattering between H and Ps(2s)by combining the con...The study of collision between metastable positronium(Ps)and antihydrogen(H)is crucial for precision experiments involving H.In this paper,we investigate the elastic scattering between H and Ps(2s)by combining the confined variational method with the projection method,for scattering energies from 0.0245 eV to 0.068 eV.Our calculations provide accurate phase shifts and cross sections for the 1,3S and 1,3P symmetries.Near the binding threshold,the rapid increase in the total cross section may be attributed to the P-wave resonance effect.Additionally,we determined the S-wave scattering lengths to be 9.34 a_(0)and 5.81 a_(0)for singlet and triplet elastic scattering,respectively.展开更多
This study analytically examines the ionization of atoms in strong near-circular laser fields.The classic Keldysh-Rutherford(KR)Coulomb-scattering(CS)model[Phys.Rev.Lett.121123201(2018)]successfully explained the atto...This study analytically examines the ionization of atoms in strong near-circular laser fields.The classic Keldysh-Rutherford(KR)Coulomb-scattering(CS)model[Phys.Rev.Lett.121123201(2018)]successfully explained the attoclock experimental curve for the H atom at lower laser intensities.Here,we develop a semiclassical model that includes the initial conditions related to the quantum properties of tunneling in the KR model at the beginning of the scattering process.This model is able to explain recent attoclock experimental curves over a wider range of laser and atomic parameters.Our results show the importance of system symmetry and quantum effects in attoclock measurements,suggesting the complex role of the Coulomb potential in strong-field ionization.展开更多
Stimulated Raman scattering(SRS)under a new ignition path that combines the advantages of direct-drive(DD)and indirect-drive(ID)schemes is investigated experimentally at the Shenguang-100 kJ facility.The results show ...Stimulated Raman scattering(SRS)under a new ignition path that combines the advantages of direct-drive(DD)and indirect-drive(ID)schemes is investigated experimentally at the Shenguang-100 kJ facility.The results show that collective SRS in the plasma produced by ablating a polyimide film is detected for the ID beams,but is suppressed by adding a toe before the main pulse of the ID beams.The toe also strongly influences SRS of both the ID and DD beams excited in the plasma generated in the hohlraum.When a toe is used,the SRS spectra of the DD beams show that SRS tends to be excited in lower plasma density,which will result in a lower risk of super-hot electrons.Measurements of hot electrons support this conclusion.This research will help us produce a better pulse design for this new ignition path.展开更多
This study introduces a comprehensive theoretical framework for accurately calculating the electronic band-structure of strained long-wavelength InAs/GaSb type-Ⅱsuperlattices.Utilizing an eight-band k·p Hamilto⁃...This study introduces a comprehensive theoretical framework for accurately calculating the electronic band-structure of strained long-wavelength InAs/GaSb type-Ⅱsuperlattices.Utilizing an eight-band k·p Hamilto⁃nian in conjunction with a scattering matrix method,the model effectively incorporates quantum confinement,strain effects,and interface states.This robust and numerically stable approach achieves exceptional agreement with experimental data,offering a reliable tool for analyzing and engineering the band structure of complex multi⁃layer systems.展开更多
Noninvasive speckle autocorrelation is a promising technique for single-shot optical imaging through scattering media.However,it fails to image multiple distinct targets within an object space through scattering media...Noninvasive speckle autocorrelation is a promising technique for single-shot optical imaging through scattering media.However,it fails to image multiple distinct targets within an object space through scattering media because it is constrained by the tiny effective range of the optical memory effect.We present a method for multi-object single-shot imaging through scattering media that incorporates deep learning into the speckle autocorrelation technique,wherein the field of view(FOV)is customized by recovered autocorrelation sidelobes,and a conventional phase-retrieval algorithm is applied to a complete set of expected speckle autocorrelations to identify multiple target objects and their relative positions.Experiments verify the feasibility of customizing the FOV for imaging through scattering media.Image reconstruction results show that the proposed approach produces superior image quality compared to existing methods.We also demonstrate its generalization capability across different object types and unknown scattering media.展开更多
A scheme based on irregular V-shaped silicon nanoantennas is proposed to optimize transverse unidirectional scattering under plane wave irradiation.Traditional methods of designing regular shapes offer fewer parameter...A scheme based on irregular V-shaped silicon nanoantennas is proposed to optimize transverse unidirectional scattering under plane wave irradiation.Traditional methods of designing regular shapes offer fewer parameters and higher search efficiency.However,due to the limitations of regular shapes,it is challenging to meet high-precision design requirements.Irregular shape design allows for a broader range of adjustments,but the complexity of shape parameters leads to lower search efficiency and a higher likelihood of converging to local optima.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.62205259,62075175,62105254,and 62375212)the National Key Laboratory of Infrared Detection Technologies(Grant No.IRDT-23-06)+1 种基金the Fundamental Research Funds for the Central Universities(Grant Nos.XJSJ24028,XJS222202,ZYTS24097,and ZYTS24095)the Open Research Fund of Beijing Key Laboratory of Advanced Optical Remote Sensing Technology.
文摘High-resolution seeing through complex scattering media such as turbid water,biological tissues,and mist is a significant challenge because the strong scattering scrambles the light paths and forms the scattering wall.We propose an active polarized iterative optimization approach for high-resolution imaging through complex scattering media.By acquiring a series of sub-polarized images,we can capture the diverse pattern-illuminated images with various high-frequency component information caused by the Brownian motion of complex scattering materials,which are processed using the common-mode rejection of polarization characteristics to extract target information from scattering medium information.Following that,our computational reconstruction technique employs an iterative optimization algorithm that commences with patternilluminated Fourier ptychography for reconstructing the high-resolution scene.It is extremely important that our approach for high-resolution imaging through complex scattering media is not limited by priori information and optical memory effect.The proposed approach is suitable for not only dynamic but also static scattering media,which may find applications in the biomedicine field,such as skin abnormalities,non-invasive blood flow,and superficial tumors.
基金supported by National Natural Science Foundation of China(12374358,91950207)Guangdong Basic and Applied Basic Research Foundation(2024A1515010420).
文摘Glucose molecules are of great significance being one of the most important molecules in metabolic chain.However,due to the small Raman scattering cross-section and weak/non-adsorption on bare metals,accurately obtaining their"fingerprint information"remains a huge obstacle.Herein,we developed a tip-enhanced Raman scattering(TERS)technique to address this challenge.Adopting an optical fiber radial vector mode internally illuminates the plasmonic fiber tip to effectively suppress the background noise while generating a strong electric-field enhanced tip hotspot.Furthermore,the tip hotspot approaching the glucose molecules was manipulated via the shear-force feedback to provide more freedom for selecting substrates.Consequently,our TERS technique achieves the visualization of all Raman modes of glucose molecules within spectral window of 400-3200 cm^(-1),which is not achievable through the far-field/surface-enhanced Raman,or the existing TERS techniques.Our TERS technique offers a powerful tool for accurately identifying Raman scattering of molecules,paving the way for biomolecular analysis.
基金Project supported by the Scientific and Technological Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202400624)the Natural Science Foundation of Chongqing CSTC(Grant No.CSTB2022NSCQBHX0020)+3 种基金the China Electronics Technology Group Corporation 44th Research Institute(Grant No.6310001-2)the Project Grant“Noninvasive Sensing Measurement based on Terahertz Technology”from Province and MOE Collaborative Innovation Centre for New Generation Information Networking and Terminalsthe Key Research Program of CQUPT on Interdisciplinary and Emerging Field(A2018-01)the Venture&Innovation Support program for Chongqing Overseas Returnees Year 2022。
文摘We investigate theoretically the enhancement of mechanical squeezing in a multimode optomechanical system by introducing a coherent phonon–photon interaction via the backward stimulated Brillouin scattering(BSBS)process.The coherent photon–phonon interaction where two optical modes couple to a Brillouin acoustic mode with a large decay rate provides an extra channel for the cooling of a Duffing mechanical oscillator.The squeezing degree and the robustness to the thermal noises of the Duffing mechanical mode can be enhanced greatly.When the Duffing nonlinearity is weak,the squeezing degree of the mechanical mode in the presence of BSBS can be improved by more than one order of magnitude compared with that in the absence of BSBS.Our scheme may be extended to other quantum systems to study novel quantum effects.
基金financial supports from National Natural Science Foundation of China(62175023).
文摘In this study,we developed a single-beam optical trap-based surface-enhanced Raman scattering(SERS)optofluidic molecular fingerprint spectroscopy detection system.This system utilizes a single-beam optical trap to concentrate free silver nanoparticles(AgNPs)within an optofluidic chip,significantly enhancing SERS performance.We investigated the optical field distribution characteristics within the tapered fiber using COMSOL simulation software and established a MATLAB simulation model to validate the single-beam optical trap's effectiveness in capturing AgNPs,demonstrating the theoretical feasibility of our approach.To verify the particle capture efficacy of the system,we experimentally controlled the optical trap's on-off state to manage the capture and release of particles precisely.The experimental results indicated that the Raman signal intensity in the capture state was significantly higher than in the non-capture state,confirming that the single-beam optical trap effectively enhances the SERS detection capability of the optofluidic detection system.Furthermore,we employed Raman mapping techniques to investigate the impact of the capture area on the SERS effect,revealing that the spectral intensity of molecular fingerprints in the laser-trapping region is significantly improved.We successfully detected the Raman spectrum of crystal violet at a concentration of 10^(−9)mol/L and pesticide thiram at a concentration of 10^(−5)mol/L,further demonstrating the ability of the single-beam optical trap in enhancing the molecular fingerprint spectrum identification capability of the SERS optofluidic chips.The optical trapping SERS optofluidic detection system developed in this study,as a key component of an integrated optoelectronic sensing system,holds the potential for integration with portable high-power lasers and high-performance Raman spectrometers.This integration is expected to advance highly integrated technologies and significantly enhance the overall performance and portability of optoelectronic sensing systems.
基金supported by the National Key Research and Development Program of China(Grant No.2021YFB3900400)the National Natural Science Foundation of China(Grant Nos.U2142212 and 42361074)。
文摘Accurate satellite data assimilation under all-sky conditions requires enhanced parameterization of scattering properties for frozen hydrometeors in clouds.This study aims to develop a nonspherical scattering look-up table that contains the optical properties of five hydrometeor types—rain,cloud water,cloud ice,graupel,and snow—for the Advanced Radiative Transfer Modeling System(ARMS)at frequencies below 220 GHz.The discrete dipole approximation(DDA)method is employed to compute the single-scattering properties of solid cloud particles,modeling these particles as aggregated roughened bullet rosettes.The bulk optical properties of the cloud layer are derived by integrating the singlescattering properties with a modified Gamma size distribution,specifically for distributions with 18 effective radii.The bulk phase function is then projected onto a series of generalized spherical functions,applying the delta-M method for truncation.The results indicate that simulations using the newly developed nonspherical scattering look-up table exhibit significant consistency with observations under deep convection conditions.In contrast,assuming spherical solid cloud particles leads to excessive scattering at mid-frequency channels and insufficient scattering at high-frequency channels.This improvement in radiative transfer simulation accuracy for cloudy conditions will better support the assimilation of allsky microwave observations into numerical weather prediction models.·Frozen cloud particles were modeled as aggregates of bullet rosettes and the optical properties at microwave range were computed by DDA.·A complete process and technical details for constructing a look-up table of ARMS are provided.·The ARMS simulations generally show agreement with observations of MWTS and MWHS under typhoon conditions using the new look-up table.
基金the National Natural Science Foundation of China(No.12174229 and 22375117)Natural Science Foundation of Shandong Province(No.ZR2022YQ02 and ZR2023MB149)Taishan Scholars Program of Shandong Province(No.tsqn202306152)for financial support.
文摘Quantitative detection of trace small-sized nanoplastics(<100 nm)remains a significant challenge in surface-enhanced Raman scattering(SERS).To tackle this issue,we developed a hydrophobic CuO@Ag nanowire substrate and introduced a multiplex-feature analysis strategy based on the coffee ring effect.This substrate not only offers high Raman enhancement but also exhibits a high probability of detection(POD),enabling rapid and accurate identification of 50 nm polystyrene nanoplastics over a broad concentration range(1–10−10 wt%).Importantly,experimental results reveal a strong correlation between the coffee ring formation and the concentration of nanoplastic dispersion.By incorporating Raman signal intensity,coffee ring diameter,and POD as combined features,we established a machine learning-based mapping between nanoplastic concentration and coffee ring characteristics,allowing precise predictions of dispersion concentration.The mean squared error of these predictions is remarkably low,ranging from 0.21 to 0.54,representing a 19 fold improvement in accuracy compared to traditional linear regression-based methods.This strategy effectively integrates SERS with wettability modification techniques,ensuring high sensitivity and fingerprinting capabilities,while addressing the limitations of Raman signal intensity in accurately reflecting concentration changes at ultra-low levels,providing a new idea for precise SERS measurements of nanoplastics.
基金supported by the Shenzhen Science and Technology Project,China(Grant No.KCXFZ20240903094301003).
文摘Passive imaging through intense atmospheric scattering is a critical yet formidable challenge in optical imaging,with profound implications across various applications.Conventional cameras struggle under severe scattering conditions,fundamentally limiting their effectiveness.We propose a groundbreaking directional atmospheric scattering model that revolutionizes passive imaging capabilities,converting a conventional camera to a super-camera.The model precisely characterizes directional photon propagation through scattering media,transforming this historically ill-posed problem into a well-posed solution,based on which a 4D spatial-angular scattering reconstruction method is proposed,which leverages both ballistic photons and directionally resolved scattered light,without relying on any scene-specific priors,to achieve unprecedented passive imaging performance enabling color imaging through over 12 transport mean free paths at distances up to 1.76 km.Our system recovers targets contributing as little as 0.00016%of the total detected signal,enhancing a standard camera’s signal recovery capacity by nearly 200×.To validate our approach,we introduce the first-ever real-world multiperspective scattering dataset,providing a critical benchmark for future research.We mark a paradigm shift in passive imaging,offering transformative potential for real-world applications under extreme atmospheric scattering conditions.
基金supported by the National Natural Science Foundation of China(Grant Nos.12088101 and No.U2330401)。
文摘Gas targets have been used to measure the scattering length in neutron-proton(n-p)scattering experiments.Changes in electron dynamics within the gas target have a negligible effect on the dynamics of nucleons.However,electron dynamics are sensitively related to the specific form of the n-p interaction during the scattering process.We propose a theoretical approach to explore electron dynamics and determine the parameters of the n-p interaction.This approach is based on a three-body scattering process involving a neutron,a proton and an electron.Numerical results indicate significant differences in electron dynamics with varying values of n-p interaction parameters,providing additional information beyond scattering cross-sections to accurately determine these parameters.
基金financially supported by the Science Center of the National Science Foundation of China (Grant No. 52088101)the National Natural Science Foundation of China (Grant Nos. 52161160334, 12274437, 12174426, and 52271237)+1 种基金the Chinese Academy of Sciences (CAS) Project for Young Scientists in Basic Research No. YSBR-084the CAS Youth Interdisciplinary Team。
文摘The mechanisms of enhancing spin-orbit torque(SOT) have attracted significant attention, particularly regarding the influence of extrinsic scattering mechanisms on SOT efficiency, as they complement intrinsic contributions. In multilayer systems, extrinsic interfacial scattering, along with scattering from defects or impurities inside the materials, plays a crucial role in affecting the SOT efficiency. In this study, we successfully fabricated high-quality epitaxially grown [Ir/Pt]N superlattices with an increasing number of interfaces using a magnetron sputtering system to investigate the contribution of extrinsic interfacial scattering to SOT efficiency. We measured SOT efficiency through spin-torque ferromagnetic resonance methods and determined the spin Hall angle using the spin pumping technique. Additionally, we calculated spin transparency based on the SOT efficiency and spin Hall angle. Our findings indicate that the values of SOT efficiency, spin Hall angle, and spin transparency are enhanced in the superlattice structure compared to Pt, which we attribute to the increase in interfacial scattering.This research offers an effective strategy for designing and fabricating advanced spintronic devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.62275188 and 62505216)the Central Guidance on Local Science and Technology Development Fund(Grant No.YDZJSX2024D019)+1 种基金the International Scientific and Technological Cooperative Project in Shanxi Province(Grant No.202104041101009)the Natural Science Foundation of Shanxi Province of China through Research Project(Grant No.20210302123195).
文摘Transforming a scattering medium into a lens for imaging very simple binary objects is possible;however,it remains challenging to image complex grayscale objects,let alone measure 3D continuous distribution objects.Here,we propose and demonstrate the use of a ground glass diffuser as a scattering lens for imaging complex grayscale fringes,and we employ it to achieve microscopic structured light 3D imaging(MSL3DI).The ubiquitous property of the speckle patterns permits the exploitation of the scattering medium as an ultra-thin scattering lens with a variable focal length and a flexible working distance for microscale object measurement.The method provides a light,flexible,and cost-effective imaging device as an alternative to microscope objectives or telecentric lenses in conventional MSL3DI systems.We experimentally demonstrate that employing a scattering lens allows us to achieve relatively good phase information and robust 3D imaging from depth measurements,yielding measurement accuracy only marginally lower than that of a telecentric lens,typically within approximately 10μm.Furthermore,the scattering lens demonstrates robust performance even when the imaging distance exceeds the typical working distance of a telecentric lens.The proposed method facilitates the application of scattering imaging techniques,providing a more flexible solution for MSL3DI.
基金supported by the Presidential Foundation of CAEP(Grant No.YZJJZL2023116)the National Nature Science Foundation of China(Grant No.12275249)the Youth Talent Fund of the Laser Fusion Research Center,CAEP(Grant Nos.RCFCZ7-2024-2 and RCFPD4-2020-4).
文摘We present experimental results on kilojoule ultraviolet laser output with 1%spectral broadening.Through stimulated rotational Raman scattering(SRRS)with signal laser injection,we achieve effective spectral broadening in short-range propagation,with good retention of the original near-field distribution and time waveform.Theoretical calculations show that 2%bandwidth spectral broadening can be achieved by injecting 20 kW/cm^(2) signal light at 2.2 GW/cm^(2) flux of the pump laser.In addition,high-frequency modulation in the near field can be effectively avoided through replacement of the original random noise signal light by the controllable signal light.The SRRS in the atmospheric environment excited with signal laser injection can provide wide-band light output with controllable beam quality without long-distance propagation,representing an important potential route to realization of broadband laser drivers.
基金supported in part by the National Key R&D Program of China(No.2023YFA1606900)the National Natural Science Foundation of China(NSFC)(Nos.12235003 and 12447106).
文摘Extreme ultraviolet(EUV)lithography is crucial for advancing semiconductor manufacturing;however,current EUV light sources,such as laser-produced plasma(LPP),have significant limitations,including low energy-conversion efficiency and debris contamination.Various schemes,including optical free-electron laser undulators,have been studied to generate coherent EUV light.However,optical undulators suffer from limited focal lengths,which pose a significant challenge to achieving a higher gain.In this study,a novel approach is proposed that employs a stretched off-axis paraboloid(sOAP)mirror,thus extending the focus distance to the centimeter range while achieving a well-controlled periodic light field.This enables high-intensity 92-eV EUV sources to exceed 1016/s,as demonstrated in the simulations.The proposed setup provides an efficient and powerful solution for advanced applications including semiconductor lithography.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1604301)the Natural Science Foundation of China(Grant Nos.12334013,12204018,9205020192250306)。
文摘The quasiparticle scattering processes of the topological surface state(TSS)in three-dimensional topological insulators(TIs)have a vital effect on the many-body interactions and potential applications of topological materials.In this study,we performed high-resolution temperature-dependent angle-resolved photoemission spectroscopy analysis of the 3D strong TI Bi_(2)Se_(3).Using an ab initio simulation,we analyzed the temperature dependence of the electronic structure and lifetime broadening of the TSS,which are closely associated with the quasiparticle scattering process,i.e.,electron–phonon coupling and spin-dependent scattering.We show that,at a low temperature(7 K),the spin-dependent electron scattering facilitates the anisotropic scattering rate of the TSS.Conversely,at room temperature(300 K),the electron–phonon coupling dominates the contribution to the scattering rate.The scattering rate increases with temperature and becomes uniform in momentum space owing to the temperature dependence of quasiparticle scattering.The quantitative study of temperature-dependent scattering rates in TSS is crucial to understanding the topological property and transport mobility of Dirac fermions for fundamental studies and potential applications.
基金W.W.was supported by the China Postdoctoral Science Foundation(Grant No.2023M741992)Z.Y.was supported by the National Natural Science Foundation of China(Grant No.11925108).
文摘In this paper,we present some properties of scattering data for the derivative nonlinear Schrödinger equation in H^(S)(R)(s≥1/2)starting from the Lax pair.We show that the reciprocal of the transmission coefficient can be expressed as the sum of some iterative integrals,and its logarithm can be written as the sum of some connected iterative integrals.We provide the asymptotic properties of the first few iterative integrals of the reciprocal of the transmission coefficient.Moreover,we provide some regularity properties of the reciprocal of the transmission coefficient related to scattering data in H^(S)(R).
基金supported by the National Natural Science Foundation of China under Grant Nos.12174399,12147146 and 11934014by the Natural Science Foundation of Hainan Province under Grant No.122QN219+1 种基金through the Innovational Fund for Scientific and Technological Personnel of Hainan Provinceby the Natural Science Foundation of Shandong Provincial under Grant No.ZR2021QA046。
文摘The study of collision between metastable positronium(Ps)and antihydrogen(H)is crucial for precision experiments involving H.In this paper,we investigate the elastic scattering between H and Ps(2s)by combining the confined variational method with the projection method,for scattering energies from 0.0245 eV to 0.068 eV.Our calculations provide accurate phase shifts and cross sections for the 1,3S and 1,3P symmetries.Near the binding threshold,the rapid increase in the total cross section may be attributed to the P-wave resonance effect.Additionally,we determined the S-wave scattering lengths to be 9.34 a_(0)and 5.81 a_(0)for singlet and triplet elastic scattering,respectively.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12174239,12347165,and 12404330)Shaanxi Fundamental Science Research Project for Mathematics and Physics(Grant No.23JSY022)+2 种基金Natural Science Basic Research Program of Shaanxi(Grant No.2022JM-015)Hebei Natural Science Foundation(Grant No.A2022205002)Science and Technology Project of Hebei Education Department(Grant No.QN2022143)。
文摘This study analytically examines the ionization of atoms in strong near-circular laser fields.The classic Keldysh-Rutherford(KR)Coulomb-scattering(CS)model[Phys.Rev.Lett.121123201(2018)]successfully explained the attoclock experimental curve for the H atom at lower laser intensities.Here,we develop a semiclassical model that includes the initial conditions related to the quantum properties of tunneling in the KR model at the beginning of the scattering process.This model is able to explain recent attoclock experimental curves over a wider range of laser and atomic parameters.Our results show the importance of system symmetry and quantum effects in attoclock measurements,suggesting the complex role of the Coulomb potential in strong-field ionization.
基金supported by the National Natural Science Foundation of China(Grant Nos.12205274,12275251,12105270,12205272,12305262,and 12035002)the National Key Laboratory of Plasma Physics(Grant No.JCKYS2024212803)+2 种基金the Fund of the National Key Laboratory of Plasma Physics(Grant No.6142A04230103)the National Key R&D Program of China(Grant No.2023YFA1608400)the National Security Academic Fund(Grant No.U2430207).
文摘Stimulated Raman scattering(SRS)under a new ignition path that combines the advantages of direct-drive(DD)and indirect-drive(ID)schemes is investigated experimentally at the Shenguang-100 kJ facility.The results show that collective SRS in the plasma produced by ablating a polyimide film is detected for the ID beams,but is suppressed by adding a toe before the main pulse of the ID beams.The toe also strongly influences SRS of both the ID and DD beams excited in the plasma generated in the hohlraum.When a toe is used,the SRS spectra of the DD beams show that SRS tends to be excited in lower plasma density,which will result in a lower risk of super-hot electrons.Measurements of hot electrons support this conclusion.This research will help us produce a better pulse design for this new ignition path.
文摘This study introduces a comprehensive theoretical framework for accurately calculating the electronic band-structure of strained long-wavelength InAs/GaSb type-Ⅱsuperlattices.Utilizing an eight-band k·p Hamilto⁃nian in conjunction with a scattering matrix method,the model effectively incorporates quantum confinement,strain effects,and interface states.This robust and numerically stable approach achieves exceptional agreement with experimental data,offering a reliable tool for analyzing and engineering the band structure of complex multi⁃layer systems.
基金supported by the National Natural Science Foundation of China(Grant No.62475164)the Guangdong Applied Basic Research Foundation(Grant No.2024A1515010370)+1 种基金the Science and Technology Innovation Commission of Shenzhen(Grant No.JCYJ20240813141402003)the Shenzhen University(Grant Nos.86902-00248 and 868-01032096).
文摘Noninvasive speckle autocorrelation is a promising technique for single-shot optical imaging through scattering media.However,it fails to image multiple distinct targets within an object space through scattering media because it is constrained by the tiny effective range of the optical memory effect.We present a method for multi-object single-shot imaging through scattering media that incorporates deep learning into the speckle autocorrelation technique,wherein the field of view(FOV)is customized by recovered autocorrelation sidelobes,and a conventional phase-retrieval algorithm is applied to a complete set of expected speckle autocorrelations to identify multiple target objects and their relative positions.Experiments verify the feasibility of customizing the FOV for imaging through scattering media.Image reconstruction results show that the proposed approach produces superior image quality compared to existing methods.We also demonstrate its generalization capability across different object types and unknown scattering media.
基金supported by the National Natural Science Foundation of China(Nos.62475121 and 62335012)。
文摘A scheme based on irregular V-shaped silicon nanoantennas is proposed to optimize transverse unidirectional scattering under plane wave irradiation.Traditional methods of designing regular shapes offer fewer parameters and higher search efficiency.However,due to the limitations of regular shapes,it is challenging to meet high-precision design requirements.Irregular shape design allows for a broader range of adjustments,but the complexity of shape parameters leads to lower search efficiency and a higher likelihood of converging to local optima.
