Fourier Ptychographic Microscopy(FPM)is a high-throughput computational optical imaging technology reported in 2013.It effectively breaks through the trade-off between high-resolution imaging and wide-field imaging.In...Fourier Ptychographic Microscopy(FPM)is a high-throughput computational optical imaging technology reported in 2013.It effectively breaks through the trade-off between high-resolution imaging and wide-field imaging.In recent years,it has been found that FPM is not only a tool to break through the trade-off between field of view and spatial resolution,but also a paradigm to break through those trade-off problems,thus attracting extensive attention.Compared with previous reviews,this review does not introduce its concept,basic principles,optical system and series of applications once again,but focuses on elaborating the three major difficulties faced by FPM technology in the process from“looking good”in the laboratory to“working well”in practical applications:mismatch between numerical model and physical reality,long reconstruction time and high computing power demand,and lack of multi-modal expansion.It introduces how to achieve key technological innovations in FPM through the dual drive of Artificial Intelligence(AI)and physics,including intelligent reconstruction algorithms introducing machine learning concepts,optical-algorithm co-design,fusion of frequency domain extrapolation methods and generative adversarial networks,multi-modal imaging schemes and data fusion enhancement,etc.,gradually solving the difficulties of FPM technology.Conversely,this review deeply considers the unique value of FPM technology in potentially feeding back to the development of“AI+optics”,such as providing AI benchmark tests under physical constraints,inspirations for the balance of computing power and bandwidth in miniaturized intelligent microscopes,and photoelectric hybrid architectures.Finally,it introduces the industrialization path and frontier directions of FPM technology,pointing out that with the promotion of the dual drive of AI and physics,it will generate a large number of industrial application case,and looks forward to the possibilities of future application scenarios and expansions,for instance,body fluid biopsy and point-of-care testing at the grassroots level represent the expansion of the growth market.展开更多
Ptychography is a diffraction-based X-ray microscopy technique in which an extended sample is scanned by a coherent beam with overlapped illuminated areas and complex transmission function of the sample is obtained by...Ptychography is a diffraction-based X-ray microscopy technique in which an extended sample is scanned by a coherent beam with overlapped illuminated areas and complex transmission function of the sample is obtained by applying iterative phase retrieval algorithms to the diffraction patterns recorded at each scanned position.It permits quantitatively imaging of non-crystalline specimens at a resolution limited only by the X-ray wavelength and the maximal scattering angle detected.In this paper,the development of soft X-ray ptychography method at the BL08U1 A beamline of Shanghai Synchrotron Radiation Facility is presented.The experimental setup,experimental parameters selection criteria,and post-experimental data analyzing procedures are presented in detail with a prospect of high-resolution image reconstruction in real time.The performance of this newly implemented method is demonstrated through the measurements of a resolution test pattern and two real samples:Pt-Co alloy nanoparticles and a breast cancer cell.The results indicate that strong scattering specimens can be reconstructed to sub-20 nm resolution,while a sub-25 nm resolution for biological specimens can be achieved.展开更多
An optical transfer function （OTF） reconstruction model is first embedded into incoherent Fourier ptychography （IFP）. The leading result is a proposed algorithm that can recover both the super-resolution image and...An optical transfer function （OTF） reconstruction model is first embedded into incoherent Fourier ptychography （IFP）. The leading result is a proposed algorithm that can recover both the super-resolution image and the OTF of an imaging system with unknown aberrations simultaneously. This model overcomes the difficult problem of OTF estimation that the previous IFP faces. The effectiveness of this algorithm is demonstrated by numerical simulations, and the superior reconstruction is presented. We believe that the reported algorithm can extend the original IFP for more complex conditions and may provide a solution by using structured light for characterization of optical systems＇ aberrations.展开更多
Fourier ptychography(FP)offers both wide field-of-view and high-resolution holographic imaging,making it valuable for applications ranging from microscopy and X-ray imaging to remote sensing.However,its practical impl...Fourier ptychography(FP)offers both wide field-of-view and high-resolution holographic imaging,making it valuable for applications ranging from microscopy and X-ray imaging to remote sensing.However,its practical implementation remains challenging due to the requirement for precise numerical forward models that accurately represent real-world imaging systems.This sensitivity to model-reality mismatches makes FP vulnerable to physical uncertainties,including misalignment,optical element aberrations,and data quality limitations.Conventional approaches address these challenges through separate methods:manual calibration or digital correction for misalignment;pupil or probe reconstruction to mitigate aberrations;or data quality enhancement through exposure adjustments or high dynamic range(HDR)techniques.Critically,these methods cannot simultaneously address the interconnected uncertainties that collectively degrade imaging performance.We introduce Uncertainty-Aware FP(UA-FP),a comprehensive framework that simultaneously addresses multiple system uncertainties without requiring complex calibration and data collection procedures.Our approach develops a fully differentiable forward imaging model that incorporates deterministic uncertainties(misalignment and optical aberrations)as optimizable parameters,while leveraging differentiable optimization with domain-specific priors to address stochastic uncertainties(noise and data quality limitations).Experimental results demonstrate that UA-FP achieves superior reconstruction quality under challenging conditions.The method maintains robust performance with reduced sub-spectrum overlap requirements and retains high-quality reconstructions even with low bit sensor data.Beyond improving image reconstruction,our approach enhances system reconfigurability and extends FP's capabilities as a measurement tool suitable for operation in environments where precise alignment and calibration are impractical.展开更多
Fourier ptychographic microscopy(FPM)is a promising technique for achieving high-resolution and large fieldof-view imaging,which is particularly suitable for pathological applications,such as imaging hematoxylin and e...Fourier ptychographic microscopy(FPM)is a promising technique for achieving high-resolution and large fieldof-view imaging,which is particularly suitable for pathological applications,such as imaging hematoxylin and eosin(H&E)stained tissues with high space-bandwidth and reduced artifacts.However,current FPM implementations require either precise system calibration and high-quality raw data,or significant computational loads due to iterative algorithms,which limits the practicality of FPM in routine pathological examinations.In this work,latent wavefront denoting the unobservable exiting wave at the surface of the sensor is introduced.A latent wavefront physical model optimized with variational expectation maximization(VEM)is proposed to tackle the inverse problem of FPM.The VEM-FPM alternates between solving a non-convex optimization problem as the main task for the latent wavefront in the spatial domain and merging together their Fourier spectrum in the Fourier plane as an intermediate product by solving a convex closed-formed Fourier space optimization.The VEM-FPM approach enables a stitching-free,full-field reconstruction for Fourier ptychography over a 5.3 mm×5.3 mm field of view,using a 2.5×objective with a numerical aperture(NA)of 0.08.The synthetic aperture achieves a resolution equivalent to 0.53 NA at 532 nm wavelength.The execution speed of VEM-FPM is twice as fast as that of state-of-the-art feature-domain methods while maintaining comparable reconstruction quality.展开更多
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
Conventional ptychography translates an object through a localized probe beam to widen the field of view in real space.Fourier ptychography translates the object spectrum through a pupil aperture to expand the Fourier...Conventional ptychography translates an object through a localized probe beam to widen the field of view in real space.Fourier ptychography translates the object spectrum through a pupil aperture to expand the Fourier bandwidth in reciprocal space.Here we report an imaging modality,termed synthetic aperture ptychography(SAP),to get the best of both techniques.In SAP,we illuminate a stationary object using an extended plane wave and translate a coded image sensor at the far field for data acquisition.The coded layer attached on the sensor modulates the object exit waves and serves as an effective ptychographic probe for phase retrieval.The sensor translation process in SAP synthesizes a large complex-valued wavefront at the intermediate aperture plane.By propagating this wavefront back to the object plane,we can widen the field of view in real space and expand the Fourier bandwidth in reciprocal space simultaneously.We validate the SAP approach with transmission targets and reflection silicon microchips.A 20-mm aperture was synthesized using a 5-mm sensor,achieving a fourfold gain in resolution and 16-fold gain in field of view for object recovery.In addition,the thin sample requirement in ptychography is no longer required in SAP.One can digitally propagate the recovered exit wave to any axial position for post-acquisition refocusing.The SAP scheme offers a solution for far-field sub-diffraction imaging without using lenses.It can be adopted in coherent diffraction imaging setups with radiation sources from visible light,extreme ultraviolet,and X-ray,to electron.展开更多
Coherent diffractive imaging （CDI） is a lensless imaging technique and can achieve a resolution beyond the Rayleigh or Abbe limit. The ptychographical iterative engine （PIE） is a CDI phase retrieval algorithm that...Coherent diffractive imaging （CDI） is a lensless imaging technique and can achieve a resolution beyond the Rayleigh or Abbe limit. The ptychographical iterative engine （PIE） is a CDI phase retrieval algorithm that uses multiple diffraction patterns obtained through the scan of a localized illumination on the specimen, which has been demonstrated successfully at optical and X-ray wavelengths. In this paper, a general PIE algorithm （gPIE） is presented and demonstrated with an He-Ne laser light diffraction dataset. This algorithm not only permits the removal of the accurate model of the illumination function in PIE, but also provides improved convergence speed and retrieval quality.展开更多
Metal halide perovskites(MHPs)are an emerging class of semiconductors that have demonstrated their promise at various energy frontiers.Especially,perovskite-based solar cells(PSCs)are considered as a disruptive photov...Metal halide perovskites(MHPs)are an emerging class of semiconductors that have demonstrated their promise at various energy frontiers.Especially,perovskite-based solar cells(PSCs)are considered as a disruptive photovoltaic technology with their power conversion efficiency rapidly climbing to certified 25.7%[1].展开更多
Mesoscopy refers to imaging methodologies that provide a field of view(FOV)ranging from several millimeters to centimeters while achieving cellular or even subcellular resolution(Figure 1).This technological framework...Mesoscopy refers to imaging methodologies that provide a field of view(FOV)ranging from several millimeters to centimeters while achieving cellular or even subcellular resolution(Figure 1).This technological framework employs specially designed large-scale objective lenses to correct aberrations across extended FOVs,synchronized with light-field acquisition modalities through either scanning point detection or large-format array detection.Conventional microscopes,constrained by the limitations of objective lenses,exhibit a trade-off between the FOV and resolution.To achieve both high resolution and a large FOV,common approaches such as FOV stitching and Fourier ptychography were employed.However,these methods were extremely slow and imposed numerous constraints on samples.In 2016,a mesoscopic objective lens was introduced to address these challenges,achieving a 6 mm FOV and 0.7 mm resolution,thereby increasing the imaging throughput of conventional objective lenses by orders of magnitude.1 In the same year,this technology was recognized as one of the top ten physics breakthroughs worldwide by Physics World.Since then,mesoscopic imaging technology has gradually gained momentum and has been applied in various fields.展开更多
Antiferromagnetic imaging is critical for understanding and optimizing the properties of antiferromagnetic materials and devices.Despite the widespread use of high-energy electrons for atomic-scale imaging,they have l...Antiferromagnetic imaging is critical for understanding and optimizing the properties of antiferromagnetic materials and devices.Despite the widespread use of high-energy electrons for atomic-scale imaging,they have low sensitivity to spin textures.Typically,the magnetic contribution to the phase of a highenergy electron wave is weaker than one percent of the electrostatic potential.Here,we demonstrate direct imaging of antiferromagnetic lattice through precise phase retrieval via electron ptychography,paving the way for magnetic lattice imaging of antiferromagnetic materials and devices.展开更多
The application of X-ray spectro-microscopy to image changes in the chemical state in application areas such as catalysis,environmental science,or biological samples can be limited by factors such as the speed of meas...The application of X-ray spectro-microscopy to image changes in the chemical state in application areas such as catalysis,environmental science,or biological samples can be limited by factors such as the speed of measurement,the presence of dilute concentrations,radiation damage,and thermal drift during the measurement.We have adapted a reduced-order model approach,known as the discrete empirical interpolation method,which identifies how to optimally subsample the spectroscopic information,accounting for background variations in the signal,to provide an accurate approximation of an equivalent full spectroscopic measurement from the sampled material.This approach uses readily available prior information to guide and significantly reduce the sampling requirements impacting both the total X-ray dose and the acquisition time.The reduced-order model approach can be adapted more broadly to any spectral or spectro-microscopy measurement where a low-rank approximation can be made from prior information on the possible states of a system,and examples of the approach are presented.展开更多
Dynamic phenomena occurring on the ultrafast time scales are inherently difficult to image.While pump–probe techniques have been used for decades,probing nonrepeatable phenomena precludes this form of imaging.Additio...Dynamic phenomena occurring on the ultrafast time scales are inherently difficult to image.While pump–probe techniques have been used for decades,probing nonrepeatable phenomena precludes this form of imaging.Additionally,many ultrafast phenomena,such as electron dynamics,exhibit low amplitude contrast in the optical wavelength range and thus require quantitative phase imaging.To better understand the underlying physics involved in a plethora of ultrafast phenomena,advanced imaging techniques must be developed to observe single events at an ultrafast time scale.Here,we present,to the best of our knowledge,the first ptychographic imaging system capable of observing ultrafast dynamics from a single event.We demonstrate ultrafast dynamic imaging by observing the conduction band electron population from a 2-photon absorption event in ZnSe pumped by a single femtosecond pulse.We verify experimental observations by comparing them to numeric solutions of a nonlinear envelope equation.Our imaging method represents a major step forward in ultrafast imaging,bringing the capabilities of ptychography to the ultrafast regime.展开更多
Table-top extreme ultraviolet(EUV)microscopy offers unique opportunities for label-free investigation of biological samples.Here,we demonstrate ptychographic EUV imaging of two dried,unstained model specimens:germling...Table-top extreme ultraviolet(EUV)microscopy offers unique opportunities for label-free investigation of biological samples.Here,we demonstrate ptychographic EUV imaging of two dried,unstained model specimens:germlings of a fungus(Aspergillus nidulans),and bacteria(Escherichia coli)cells at 13.5 nm wavelength.We find that the EUV spectral region,which to date has not received much attention for biological imaging,offers sufficient penetration depths for the identification of intracellular features.By implementing a position-correlated ptychography approach,we demonstrate a millimeter-squared field of view enabled by infrared illumination combined with sub-60 nm spatial resolution achieved with EUV illumination on selected regions of interest.The strong element contrast at 13.5 nm wavelength enables the identification of the nanoscale material composition inside the specimens.Our work will advance and facilitate EUV imaging applications and enable further possibilities in life science.展开更多
Abbe’s resolution limit,one of the best-known physical limitations,poses a great challenge for any wave system in imaging,wave transport,and dynamics.Originally formulated in linear optics,the Abbe limit can be broke...Abbe’s resolution limit,one of the best-known physical limitations,poses a great challenge for any wave system in imaging,wave transport,and dynamics.Originally formulated in linear optics,the Abbe limit can be broken using nonlinear optical interactions.We extend the Abbe theory into a nonlinear regime and experimentally demonstrate a far-field,label-free,and scan-free super-resolution imaging technique based on nonlinear four-wave mixing to retrieve near-field scattered evanescent waves,achieving a sub-wavelength resolution ofλ∕5.6.This method paves the way for numerous new applications in biomedical imaging,semiconductor metrology,and photolithography.展开更多
Multilayer Laue lenses are volume diffraction elements for the efficient focusing of X-rays.With a new manufacturing technique that we introduced,it is possible to fabricate lenses of sufficiently high numerical apert...Multilayer Laue lenses are volume diffraction elements for the efficient focusing of X-rays.With a new manufacturing technique that we introduced,it is possible to fabricate lenses of sufficiently high numerical aperture(NA)to achieve focal spot sizes below 10 nm.The alternating layers of the materials that form the lens must span a broad range of thicknesses on the nanometer scale to achieve the necessary range of X-ray deflection angles required to achieve a high NA.This poses a challenge to both the accuracy of the deposition process and the control of the materials properties,which often vary with layer thickness.We introduced a new pair of materials—tungsten carbide and silicon carbide—to prepare layered structures with smooth and sharp interfaces and with no material phase transitions that hampered the manufacture of previous lenses.Using a pair of multilayer Laue lenses(MLLs)fabricated from this system,we achieved a two-dimensional focus of 8.4×6.8 nm2 at a photon energy of 16.3 keV with high diffraction efficiency and demonstrated scanning-based imaging of samples with a resolution well below 10 nm.The high NA also allowed projection holographic imaging with strong phase contrast over a large range of magnifications.An error analysis indicates the possibility of achieving 1 nm focusing.展开更多
The in situ physicochemical analysis of nanostructured functional materials is crucial for advances in their design and production. X-ray coherent diffraction imaging （CDI） methods have recently demonstrated impress...The in situ physicochemical analysis of nanostructured functional materials is crucial for advances in their design and production. X-ray coherent diffraction imaging （CDI） methods have recently demonstrated impressive potential for characterizing such materials with a high spatial resolution and elemental sensitivity; however, moving from the current ex situ static regime to the in situ dynamic one remains a challenge. By combining soft X-ray ptychography and single-shot keyhole CDI, we performed the first in situ spatiotemporal study on an electrodeposition process in a sealed wet environment, employed for the fabrication of oxygen-reduction catalysts, which are key components for alkaline fuel cells and metal-air batteries. The results provide the first experimental demonstration of theoretically predicted Turing-Hopf electrochemical pattern formation resulting from morphochemical coupling, adding a new dimension for the in-depth in situ characterization of electrodeposition processes in space and time.展开更多
基金National Natural Science Foundation of China(No.12574332)the Space Optoelectronic Measurement and Perception Lab.,Beijing Institute of Control Engineering(No.LabSOMP-2023-10)Major Science and Technology Innovation Program of Xianyang City(No.L2024-ZDKJ-ZDCGZH-0021)。
文摘Fourier Ptychographic Microscopy(FPM)is a high-throughput computational optical imaging technology reported in 2013.It effectively breaks through the trade-off between high-resolution imaging and wide-field imaging.In recent years,it has been found that FPM is not only a tool to break through the trade-off between field of view and spatial resolution,but also a paradigm to break through those trade-off problems,thus attracting extensive attention.Compared with previous reviews,this review does not introduce its concept,basic principles,optical system and series of applications once again,but focuses on elaborating the three major difficulties faced by FPM technology in the process from“looking good”in the laboratory to“working well”in practical applications:mismatch between numerical model and physical reality,long reconstruction time and high computing power demand,and lack of multi-modal expansion.It introduces how to achieve key technological innovations in FPM through the dual drive of Artificial Intelligence(AI)and physics,including intelligent reconstruction algorithms introducing machine learning concepts,optical-algorithm co-design,fusion of frequency domain extrapolation methods and generative adversarial networks,multi-modal imaging schemes and data fusion enhancement,etc.,gradually solving the difficulties of FPM technology.Conversely,this review deeply considers the unique value of FPM technology in potentially feeding back to the development of“AI+optics”,such as providing AI benchmark tests under physical constraints,inspirations for the balance of computing power and bandwidth in miniaturized intelligent microscopes,and photoelectric hybrid architectures.Finally,it introduces the industrialization path and frontier directions of FPM technology,pointing out that with the promotion of the dual drive of AI and physics,it will generate a large number of industrial application case,and looks forward to the possibilities of future application scenarios and expansions,for instance,body fluid biopsy and point-of-care testing at the grassroots level represent the expansion of the growth market.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.11225527,11575283,11505277)the Ministry of Science and Technology of China(2012CB825705)
文摘Ptychography is a diffraction-based X-ray microscopy technique in which an extended sample is scanned by a coherent beam with overlapped illuminated areas and complex transmission function of the sample is obtained by applying iterative phase retrieval algorithms to the diffraction patterns recorded at each scanned position.It permits quantitatively imaging of non-crystalline specimens at a resolution limited only by the X-ray wavelength and the maximal scattering angle detected.In this paper,the development of soft X-ray ptychography method at the BL08U1 A beamline of Shanghai Synchrotron Radiation Facility is presented.The experimental setup,experimental parameters selection criteria,and post-experimental data analyzing procedures are presented in detail with a prospect of high-resolution image reconstruction in real time.The performance of this newly implemented method is demonstrated through the measurements of a resolution test pattern and two real samples:Pt-Co alloy nanoparticles and a breast cancer cell.The results indicate that strong scattering specimens can be reconstructed to sub-20 nm resolution,while a sub-25 nm resolution for biological specimens can be achieved.
基金Supported by the National Natural Science Foundation of China under Grant No 61205144the Research Project of National University of Defense Technology under Grant No JC13-07-01the Key Laboratory of High Power Laser and Physics of Chinese Academy of Sciences
文摘An optical transfer function （OTF） reconstruction model is first embedded into incoherent Fourier ptychography （IFP）. The leading result is a proposed algorithm that can recover both the super-resolution image and the OTF of an imaging system with unknown aberrations simultaneously. This model overcomes the difficult problem of OTF estimation that the previous IFP faces. The effectiveness of this algorithm is demonstrated by numerical simulations, and the superior reconstruction is presented. We believe that the reported algorithm can extend the original IFP for more complex conditions and may provide a solution by using structured light for characterization of optical systems＇ aberrations.
基金supported by the Hong Kong Research Grants Council(GRF 17200321,GRF 17201822)Y.W.and J.W.work was supported by the National Natural Science Foundation of China(62275178).
文摘Fourier ptychography(FP)offers both wide field-of-view and high-resolution holographic imaging,making it valuable for applications ranging from microscopy and X-ray imaging to remote sensing.However,its practical implementation remains challenging due to the requirement for precise numerical forward models that accurately represent real-world imaging systems.This sensitivity to model-reality mismatches makes FP vulnerable to physical uncertainties,including misalignment,optical element aberrations,and data quality limitations.Conventional approaches address these challenges through separate methods:manual calibration or digital correction for misalignment;pupil or probe reconstruction to mitigate aberrations;or data quality enhancement through exposure adjustments or high dynamic range(HDR)techniques.Critically,these methods cannot simultaneously address the interconnected uncertainties that collectively degrade imaging performance.We introduce Uncertainty-Aware FP(UA-FP),a comprehensive framework that simultaneously addresses multiple system uncertainties without requiring complex calibration and data collection procedures.Our approach develops a fully differentiable forward imaging model that incorporates deterministic uncertainties(misalignment and optical aberrations)as optimizable parameters,while leveraging differentiable optimization with domain-specific priors to address stochastic uncertainties(noise and data quality limitations).Experimental results demonstrate that UA-FP achieves superior reconstruction quality under challenging conditions.The method maintains robust performance with reduced sub-spectrum overlap requirements and retains high-quality reconstructions even with low bit sensor data.Beyond improving image reconstruction,our approach enhances system reconfigurability and extends FP's capabilities as a measurement tool suitable for operation in environments where precise alignment and calibration are impractical.
基金National Natural Science Foundation of China(62235009)。
文摘Fourier ptychographic microscopy(FPM)is a promising technique for achieving high-resolution and large fieldof-view imaging,which is particularly suitable for pathological applications,such as imaging hematoxylin and eosin(H&E)stained tissues with high space-bandwidth and reduced artifacts.However,current FPM implementations require either precise system calibration and high-quality raw data,or significant computational loads due to iterative algorithms,which limits the practicality of FPM in routine pathological examinations.In this work,latent wavefront denoting the unobservable exiting wave at the surface of the sensor is introduced.A latent wavefront physical model optimized with variational expectation maximization(VEM)is proposed to tackle the inverse problem of FPM.The VEM-FPM alternates between solving a non-convex optimization problem as the main task for the latent wavefront in the spatial domain and merging together their Fourier spectrum in the Fourier plane as an intermediate product by solving a convex closed-formed Fourier space optimization.The VEM-FPM approach enables a stitching-free,full-field reconstruction for Fourier ptychography over a 5.3 mm×5.3 mm field of view,using a 2.5×objective with a numerical aperture(NA)of 0.08.The synthetic aperture achieves a resolution equivalent to 0.53 NA at 532 nm wavelength.The execution speed of VEM-FPM is twice as fast as that of state-of-the-art feature-domain methods while maintaining comparable reconstruction quality.
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.
文摘Conventional ptychography translates an object through a localized probe beam to widen the field of view in real space.Fourier ptychography translates the object spectrum through a pupil aperture to expand the Fourier bandwidth in reciprocal space.Here we report an imaging modality,termed synthetic aperture ptychography(SAP),to get the best of both techniques.In SAP,we illuminate a stationary object using an extended plane wave and translate a coded image sensor at the far field for data acquisition.The coded layer attached on the sensor modulates the object exit waves and serves as an effective ptychographic probe for phase retrieval.The sensor translation process in SAP synthesizes a large complex-valued wavefront at the intermediate aperture plane.By propagating this wavefront back to the object plane,we can widen the field of view in real space and expand the Fourier bandwidth in reciprocal space simultaneously.We validate the SAP approach with transmission targets and reflection silicon microchips.A 20-mm aperture was synthesized using a 5-mm sensor,achieving a fourfold gain in resolution and 16-fold gain in field of view for object recovery.In addition,the thin sample requirement in ptychography is no longer required in SAP.One can digitally propagate the recovered exit wave to any axial position for post-acquisition refocusing.The SAP scheme offers a solution for far-field sub-diffraction imaging without using lenses.It can be adopted in coherent diffraction imaging setups with radiation sources from visible light,extreme ultraviolet,and X-ray,to electron.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11179009 and 50875013)the Beijing Municipal Natural Science Foundation, China (Grant No. 4102036)the Beijing NOVA Program, China (Grant No. 2009A09)
文摘Coherent diffractive imaging （CDI） is a lensless imaging technique and can achieve a resolution beyond the Rayleigh or Abbe limit. The ptychographical iterative engine （PIE） is a CDI phase retrieval algorithm that uses multiple diffraction patterns obtained through the scan of a localized illumination on the specimen, which has been demonstrated successfully at optical and X-ray wavelengths. In this paper, a general PIE algorithm （gPIE） is presented and demonstrated with an He-Ne laser light diffraction dataset. This algorithm not only permits the removal of the accurate model of the illumination function in PIE, but also provides improved convergence speed and retrieval quality.
基金startup grants,Initiation Grant-Faculty Niche Research Areas(IG-FNRA)2020/21Interdisciplinary Matching Scheme 2020/21 of the Hong Kong Baptist University(HKBU)+1 种基金the Early Career Scheme(No.22300221)from the Hong Kong Research Grant Councilthe support of the Hong Kong Ph.D.Fellowship Scheme。
文摘Metal halide perovskites(MHPs)are an emerging class of semiconductors that have demonstrated their promise at various energy frontiers.Especially,perovskite-based solar cells(PSCs)are considered as a disruptive photovoltaic technology with their power conversion efficiency rapidly climbing to certified 25.7%[1].
基金supported by the Chinese Academy of Sciences Project for Young Scientists in Basic Research(YSBR067)the Natural Science Foundation of Jiangsu Province(BK20240024)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y2023087)。
文摘Mesoscopy refers to imaging methodologies that provide a field of view(FOV)ranging from several millimeters to centimeters while achieving cellular or even subcellular resolution(Figure 1).This technological framework employs specially designed large-scale objective lenses to correct aberrations across extended FOVs,synchronized with light-field acquisition modalities through either scanning point detection or large-format array detection.Conventional microscopes,constrained by the limitations of objective lenses,exhibit a trade-off between the FOV and resolution.To achieve both high resolution and a large FOV,common approaches such as FOV stitching and Fourier ptychography were employed.However,these methods were extremely slow and imposed numerous constraints on samples.In 2016,a mesoscopic objective lens was introduced to address these challenges,achieving a 6 mm FOV and 0.7 mm resolution,thereby increasing the imaging throughput of conventional objective lenses by orders of magnitude.1 In the same year,this technology was recognized as one of the top ten physics breakthroughs worldwide by Physics World.Since then,mesoscopic imaging technology has gradually gained momentum and has been applied in various fields.
基金supported by the National Natural Science Foundation of China(52388201 and 51525102)the support from the Physical Sciences Center and Center of High-Performance Computing,Tsinghua University.
文摘Antiferromagnetic imaging is critical for understanding and optimizing the properties of antiferromagnetic materials and devices.Despite the widespread use of high-energy electrons for atomic-scale imaging,they have low sensitivity to spin textures.Typically,the magnetic contribution to the phase of a highenergy electron wave is weaker than one percent of the electrostatic potential.Here,we demonstrate direct imaging of antiferromagnetic lattice through precise phase retrieval via electron ptychography,paving the way for magnetic lattice imaging of antiferromagnetic materials and devices.
文摘The application of X-ray spectro-microscopy to image changes in the chemical state in application areas such as catalysis,environmental science,or biological samples can be limited by factors such as the speed of measurement,the presence of dilute concentrations,radiation damage,and thermal drift during the measurement.We have adapted a reduced-order model approach,known as the discrete empirical interpolation method,which identifies how to optimally subsample the spectroscopic information,accounting for background variations in the signal,to provide an accurate approximation of an equivalent full spectroscopic measurement from the sampled material.This approach uses readily available prior information to guide and significantly reduce the sampling requirements impacting both the total X-ray dose and the acquisition time.The reduced-order model approach can be adapted more broadly to any spectral or spectro-microscopy measurement where a low-rank approximation can be made from prior information on the possible states of a system,and examples of the approach are presented.
基金funded through the Air Force Office of Scientific Research(FA9550-22-1-0495)the Los Alamos National Laboratory。
文摘Dynamic phenomena occurring on the ultrafast time scales are inherently difficult to image.While pump–probe techniques have been used for decades,probing nonrepeatable phenomena precludes this form of imaging.Additionally,many ultrafast phenomena,such as electron dynamics,exhibit low amplitude contrast in the optical wavelength range and thus require quantitative phase imaging.To better understand the underlying physics involved in a plethora of ultrafast phenomena,advanced imaging techniques must be developed to observe single events at an ultrafast time scale.Here,we present,to the best of our knowledge,the first ptychographic imaging system capable of observing ultrafast dynamics from a single event.We demonstrate ultrafast dynamic imaging by observing the conduction band electron population from a 2-photon absorption event in ZnSe pumped by a single femtosecond pulse.We verify experimental observations by comparing them to numeric solutions of a nonlinear envelope equation.Our imaging method represents a major step forward in ultrafast imaging,bringing the capabilities of ptychography to the ultrafast regime.
基金Strategy and Innovation Grant from the Free State of Thuringia(41-5507-2016)Innovation Pool of the Research Field Matter of the Helmholtz Association of German Research Centers(project FISCOV)+5 种基金Leibniz Research Cluster InfectoOptics(SAS-2015-HKI-LWC)Thüringer Ministerium für Bildung,Wissenschaft und Kultur(2018 FGR 0080)Helmholtz Association(incubator project Ptychography 4.0)Fraunhofer-Gesellschaft(Cluster of Excellence Advanced Photon Sources)German Research Foundation(Deutsche Forschungsgemeinschaft,DFG)under Germany’s Excellence Strategy–EXC 2051–Project-ID 390713860S.H.is supported by the German Research Foundation(Deutsche Forschungs-gemeinschaft,DFG)–SFB 1127/2 ChemBioSys–239748522.
文摘Table-top extreme ultraviolet(EUV)microscopy offers unique opportunities for label-free investigation of biological samples.Here,we demonstrate ptychographic EUV imaging of two dried,unstained model specimens:germlings of a fungus(Aspergillus nidulans),and bacteria(Escherichia coli)cells at 13.5 nm wavelength.We find that the EUV spectral region,which to date has not received much attention for biological imaging,offers sufficient penetration depths for the identification of intracellular features.By implementing a position-correlated ptychography approach,we demonstrate a millimeter-squared field of view enabled by infrared illumination combined with sub-60 nm spatial resolution achieved with EUV illumination on selected regions of interest.The strong element contrast at 13.5 nm wavelength enables the identification of the nanoscale material composition inside the specimens.Our work will advance and facilitate EUV imaging applications and enable further possibilities in life science.
基金This work was supported by the National Key Research and Development Program(Grant Nos.2016YFA0302500 and 2017YFA0303700)National Natural Science Foundation of China(Grant Nos.92050113 and 11674228)Shanghai MEC Scientific Innovation Program(Grant No.E00075).
文摘Abbe’s resolution limit,one of the best-known physical limitations,poses a great challenge for any wave system in imaging,wave transport,and dynamics.Originally formulated in linear optics,the Abbe limit can be broken using nonlinear optical interactions.We extend the Abbe theory into a nonlinear regime and experimentally demonstrate a far-field,label-free,and scan-free super-resolution imaging technique based on nonlinear four-wave mixing to retrieve near-field scattered evanescent waves,achieving a sub-wavelength resolution ofλ∕5.6.This method paves the way for numerous new applications in biomedical imaging,semiconductor metrology,and photolithography.
基金supported by Joachim Herz Stiftungthe Helmholtz Association through program-oriented funds.
文摘Multilayer Laue lenses are volume diffraction elements for the efficient focusing of X-rays.With a new manufacturing technique that we introduced,it is possible to fabricate lenses of sufficiently high numerical aperture(NA)to achieve focal spot sizes below 10 nm.The alternating layers of the materials that form the lens must span a broad range of thicknesses on the nanometer scale to achieve the necessary range of X-ray deflection angles required to achieve a high NA.This poses a challenge to both the accuracy of the deposition process and the control of the materials properties,which often vary with layer thickness.We introduced a new pair of materials—tungsten carbide and silicon carbide—to prepare layered structures with smooth and sharp interfaces and with no material phase transitions that hampered the manufacture of previous lenses.Using a pair of multilayer Laue lenses(MLLs)fabricated from this system,we achieved a two-dimensional focus of 8.4×6.8 nm2 at a photon energy of 16.3 keV with high diffraction efficiency and demonstrated scanning-based imaging of samples with a resolution well below 10 nm.The high NA also allowed projection holographic imaging with strong phase contrast over a large range of magnifications.An error analysis indicates the possibility of achieving 1 nm focusing.
文摘The in situ physicochemical analysis of nanostructured functional materials is crucial for advances in their design and production. X-ray coherent diffraction imaging （CDI） methods have recently demonstrated impressive potential for characterizing such materials with a high spatial resolution and elemental sensitivity; however, moving from the current ex situ static regime to the in situ dynamic one remains a challenge. By combining soft X-ray ptychography and single-shot keyhole CDI, we performed the first in situ spatiotemporal study on an electrodeposition process in a sealed wet environment, employed for the fabrication of oxygen-reduction catalysts, which are key components for alkaline fuel cells and metal-air batteries. The results provide the first experimental demonstration of theoretically predicted Turing-Hopf electrochemical pattern formation resulting from morphochemical coupling, adding a new dimension for the in-depth in situ characterization of electrodeposition processes in space and time.
