Quantitative phase microscopy(QPM)enables label-free imaging and precise characterization of transparent specimens by measuring phase delay.However,optical aberrations induce wavefront distortions that degrade phase r...Quantitative phase microscopy(QPM)enables label-free imaging and precise characterization of transparent specimens by measuring phase delay.However,optical aberrations induce wavefront distortions that degrade phase reconstruction accuracy,resolution,and contrast.Existing strategies require diverse measurements or iterative optimization,limiting flexibility for real-time applications.We propose an adaptive aberration-corrected QPM system enabled by a physics-informed cycle-consistent network(PICNet)without prior calibration.By incorporating a learnable physical forward model to approximate the practical image formation and enforcing cycle consistency between object and measurement domains,PICNet can reconstruct the object phase from a single-shot measurement while simultaneously inferring complex aberrations that are difficult to characterize explicitly.Our approach achieves a 60%improvement in structural similarity compared with uncorrected results.Experiments demonstrate that PICNet enables rapid and highfidelity phase retrieval across diverse biological samples with enhanced robustness to aberrations.This physically reliable and self-calibrating framework establishes a general paradigm for solving inverse problems across various computational imaging modalities.展开更多
Differential phase contrast microscopy(DPC) provides high-resolution quantitative phase distribution of thin transparent samples under multi-axis asymmetric illuminations. Typically, illumination in DPC microscopic sy...Differential phase contrast microscopy(DPC) provides high-resolution quantitative phase distribution of thin transparent samples under multi-axis asymmetric illuminations. Typically, illumination in DPC microscopic systems is designed with two-axis half-circle amplitude patterns, which, however, result in a non-isotropic phase contrast transfer function(PTF). Efforts have been made to achieve isotropic DPC by replacing the conventional half-circle illumination aperture with radially asymmetric patterns with three-axis illumination or gradient amplitude patterns with two-axis illumination. Nevertheless, the underlying theoretical mechanism of isotropic PTF has not been explored, and thus, the optimal illumination scheme cannot be determined. Furthermore, the frequency responses of the PTFs under these engineered illuminations have not been fully optimized, leading to suboptimal phase contrast and signal-to-noise ratio for phase reconstruction. In this paper, we provide a rigorous theoretical analysis about the necessary and sufficient conditions for DPC to achieve isotropic PTF. In addition,we derive the optimal illumination scheme to maximize the frequency response for both low and high frequencies(from 0 to 2 NAobj) and meanwhile achieve perfectly isotropic PTF with only two-axis intensity measurements.We present the derivation, implementation, simulation, and experimental results demonstrating the superiority of our method over existing illumination schemes in both the phase reconstruction accuracy and noise-robustness.展开更多
Quantitative phase imaging(QPI)has emerged as a valuable tool for biomedical research thanks to its unique capabilities for quantifying optical thickness variation of living cells and tissues.Among many QPI methods,Fo...Quantitative phase imaging(QPI)has emerged as a valuable tool for biomedical research thanks to its unique capabilities for quantifying optical thickness variation of living cells and tissues.Among many QPI methods,Fourier ptychographic microscopy(FPM)allows long-term label-free observation and quantitative analysis of large cell populations without compromising spatial and temporal resolution.However,high spatio-temporal resolution imaging over a long-time scale(from hours to days)remains a critical challenge:optically inhomogeneous structure of biological specimens as well as mechanical perturbations and thermal fluctuations of the microscope body all result in time-varying aberration and focus drifts,significantly degrading the imaging performance for long-term study.Moreover,the aberrations are sample-and environmentdependent,and cannot be compensated by a fixed optical design,thus necessitating rapid dynamic correction in the imaging process.Here,we report an adaptive optical QPI method based on annular illumination FPM.In this method,the annular matched illumination configuration(i.e.,the illumination numerical aperture(NA)strictly equals to the objective NA),which is the key for recovering low-frequency phase information,is further utilized for the accurate imaging aberration characterization.By using only 6 low-resolution images captured with 6 different illumination angles matching the NA of a 10x,0.4 NA objective,we recover high-resolution quantitative phase images(synthetic NA of 0.8)and characterize the aberrations in real time,restoring the optimum resolution of the system adaptively.Applying our method to live-cell imaging,we achieve diffraction-limited performance(full-pitch resolution of 655 nm at a wavelength of 525 nm)across a wide field of view(1.77mm2)over an extended period of time.展开更多
Since the invention of Zernike phase contrast method in 1930,it has been widely used in optical microscopy and more recently in X-ray microscopy.Considering the image contrast is a mixture of absorption and phase info...Since the invention of Zernike phase contrast method in 1930,it has been widely used in optical microscopy and more recently in X-ray microscopy.Considering the image contrast is a mixture of absorption and phase information,we recently have proposed and demonstrated a method for quantitative phase retrieval in Zernike phase contrast X-ray microscopy.In this contribution,we analyze the performance of this method at different photon energies.Intensity images of PMMA samples are simulated at 2.5 keV and 6.2 keV,respectively,and phase retrieval is performed using the proposed method.The results demonstrate that the proposed phase retrieval method is applicable over a wide energy range.For weakly absorbing features,the optimal photon energy is 2.5 keV,from the point of view of image contrast and accuracy of phase retrieval.On the other hand,in the case of strong absorption objects,a higher photon energy is preferred to reduce the error of phase retrieval.These results can be used as guidelines to perform quantitative phase retrieval in Zernike phase contrast X-ray microscopy with the proposed method.展开更多
Red blood cell(RBC)indices serve as clinically important parameters for diagnosing various blood-related diseases.Conventional hematology analyzers provide the highly accurate detection of RBC indices but require larg...Red blood cell(RBC)indices serve as clinically important parameters for diagnosing various blood-related diseases.Conventional hematology analyzers provide the highly accurate detection of RBC indices but require large blood volumes(>1 mL),and the results are bulk mean values averaged over a large number of RBCs.Moreover,they do not provide quantitative information related to the morphological and chemical alteration of RBCs at the single-cell level.Recently,quantitative phase imaging(QPI)methods have been introduced as viable detection platforms for RBC indices.However,coherent QPI methods are built on complex optical setups and suffer from coherent speckle noise,which limits their detection accuracy and precision.Here,we present spectroscopic differential phase-contrast(sDPC)microscopy as a platform for measuring RBC indices.sDPC is a computational microscope that produces color-dependent phase images with higher spatial resolution and reduced speckle noise compared to coherent QPIs.Using these spectroscopic phase images and computational algorithms,RBC indices can be extracted with high accuracy.We experimentally demonstrate that sDPC enables the high-accuracy measurement of the mean corpuscular hemoglobin concentration,mean corpuscular volume,mean corpuscular hemoglobin,red cell distribution width,hematocrit,hemoglobin concentration,and RBC count with errors smaller than 7%as compared to a clinical hematology analyzer based on flow cytometry(XN-2000;Sysmex,Kobe,Japan).We further validate the clinical utility of the sDPC method by measuring and comparing the RBC indices of the control and anemic groups against those obtained using the clinical hematology analyzer.展开更多
Antiferromagnetism has become a promising candidate for the next generation electronic devices due to its thermal stability,low energy consumption,and fast switching speed.However,the canceling of the net magnetic mom...Antiferromagnetism has become a promising candidate for the next generation electronic devices due to its thermal stability,low energy consumption,and fast switching speed.However,the canceling of the net magnetic moment in antiferromagnetic order presents great challenge on quantitative characterization and modulation,hindering its investigation and application.In this work,utilizing the optical second harmonic generation(SHG)in a wide temperature range,the integrated differential phase contrast scanning transmission electron microscopy,and firstprinciples calculations,we performed a quantitative study on the evolution of non-collinear antiferromagnetic order in BiFeO_(3)films with a series of strains.We found that the antiferromagnetic coupling was significantly enhanced,featured by the increase of Néel temperature from 428 K to 646 K,and by one order of enhancement of SHG intensity contributed from the G-type antiferromagnetic order by strain manipulation from-2.4%to+0.6%.We attributed the enhancement of the antiferromagnetic coupling to the enhancement of the superexchange interaction as the Fe-O-Fe bond angle approaches 180°when the in-plane lattice constants increase,which might also result in a tendency from a non-collinear antiferromagnetic order to a collinear one.Our work not only bridges the antiferromagnetic order and the strain manipulation in epitaxial multiferroics,more importantly,also paves a way for quantitative characterization by SHG technology and the precise manipulation of antiferromagnetism.展开更多
The transport of intensity equation(TIE)is a well-established phase retrieval technique that enables incoherent diffraction limit-resolution imaging and is compatible with widely available brightfield microscopy hardw...The transport of intensity equation(TIE)is a well-established phase retrieval technique that enables incoherent diffraction limit-resolution imaging and is compatible with widely available brightfield microscopy hardware.However,existing TIE methods encounter difficulties in decoupling the independent contributions of phase and aberrations to the measurements in the case of unknown pupil function.Additionally,spatially nonuniform and temporally varied aberrations dramatically degrade the imaging performance for long-term research.Hence,it remains a critical challenge to realize the high-throughput quantitative phase imaging(QPI)with aberration correction under partially coherent illumination.To address these issues,we propose a novel method for highthroughput microscopy with annular illumination,termed as transport-of-intensity QPI with aberration correction(TI-AC).By combining aberration correction and pixel super-resolution technique,TI-AC is made compatible with large pixel-size sensors to enable a broader field of view.Furthermore,it surpasses the theoretical Nyquist-Shannon sampling resolution limit,resulting in an improvement of more than two times.Experimental results demonstrate that the half-width imaging resolution can be improved to~345 nm across a 10×field of view of 1.77 mm^(2)(0.4 NA).Given its high-throughput capability for QPI,TI-AC is expected to be adopted in biomedical fields,such as drug discovery and cancer diagnostics.展开更多
A new optical microscopy technique,termed high spatial and temporal resolution synthetic aperture phase microscopy(HISTR-SAPM),is proposed to improve the lateral resolution of wide-field coherent imaging.Under plane w...A new optical microscopy technique,termed high spatial and temporal resolution synthetic aperture phase microscopy(HISTR-SAPM),is proposed to improve the lateral resolution of wide-field coherent imaging.Under plane wave illumination,the resolution is increased by twofold to around 260 nm,while achieving millisecond-level temporal resolution.In HISTR-SAPM,digital micromirror devices are used to actively change the sample illumination beam angle at high speed with high stability.An off-axis interferometer is used to measure the sample scattered complex fields,which are then processed to reconstruct high-resolution phase images.Using HISTR-SAPM,we are able to map the height profiles of subwavelength photonic structures and resolve the period structures that have 198 nm linewidth and 132 nm gap(i.e.,a full pitch of 330 nm).As the reconstruction averages out laser speckle noise while maintaining high temporal resolution,HISTR-SAPM further enables imaging and quantification of nanoscale dynamics of live cells,such as red blood cell membrane fluctuations and subcellular structure dynamics within nucleated cells.We envision that HISTR-SAPM will broadly benefit research in material science and biology.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.62235009,62305183,and 624B2080).
文摘Quantitative phase microscopy(QPM)enables label-free imaging and precise characterization of transparent specimens by measuring phase delay.However,optical aberrations induce wavefront distortions that degrade phase reconstruction accuracy,resolution,and contrast.Existing strategies require diverse measurements or iterative optimization,limiting flexibility for real-time applications.We propose an adaptive aberration-corrected QPM system enabled by a physics-informed cycle-consistent network(PICNet)without prior calibration.By incorporating a learnable physical forward model to approximate the practical image formation and enforcing cycle consistency between object and measurement domains,PICNet can reconstruct the object phase from a single-shot measurement while simultaneously inferring complex aberrations that are difficult to characterize explicitly.Our approach achieves a 60%improvement in structural similarity compared with uncorrected results.Experiments demonstrate that PICNet enables rapid and highfidelity phase retrieval across diverse biological samples with enhanced robustness to aberrations.This physically reliable and self-calibrating framework establishes a general paradigm for solving inverse problems across various computational imaging modalities.
基金National Natural Science Foundation of China(NSFC)(61722506,11574152)Final Assembly “13th FiveYear Plan” Advanced Research Project of China(30102070102)+6 种基金Equipment Advanced Research Fund of China(61404150202)National Defense Science and Technology Foundation of China(0106173)Outstanding Youth Foundation of Jiangsu Province of China(BK20170034)Key Research and Development Program of Jiangsu Province(BE2017162)“333 Engineering”Research Project of Jiangsu Province(BRA2016407)Fundamental Research Funds for the Central Universities(30917011204)Open Research Fund of Jiangsu Key Laboratory of Spectral Imaging&Intelligent Sense(3091801410411)
文摘Differential phase contrast microscopy(DPC) provides high-resolution quantitative phase distribution of thin transparent samples under multi-axis asymmetric illuminations. Typically, illumination in DPC microscopic systems is designed with two-axis half-circle amplitude patterns, which, however, result in a non-isotropic phase contrast transfer function(PTF). Efforts have been made to achieve isotropic DPC by replacing the conventional half-circle illumination aperture with radially asymmetric patterns with three-axis illumination or gradient amplitude patterns with two-axis illumination. Nevertheless, the underlying theoretical mechanism of isotropic PTF has not been explored, and thus, the optimal illumination scheme cannot be determined. Furthermore, the frequency responses of the PTFs under these engineered illuminations have not been fully optimized, leading to suboptimal phase contrast and signal-to-noise ratio for phase reconstruction. In this paper, we provide a rigorous theoretical analysis about the necessary and sufficient conditions for DPC to achieve isotropic PTF. In addition,we derive the optimal illumination scheme to maximize the frequency response for both low and high frequencies(from 0 to 2 NAobj) and meanwhile achieve perfectly isotropic PTF with only two-axis intensity measurements.We present the derivation, implementation, simulation, and experimental results demonstrating the superiority of our method over existing illumination schemes in both the phase reconstruction accuracy and noise-robustness.
基金supported by the National Natural Science Foundation of China(61905115,62105151,62175109,U21B2033,62105156)Leading Technology of Jiangsu Basic Research Plan(BK20192003),Youth Foundation of Jiangsu Province(BK20190445,BK20210338)+1 种基金Fundamental Research Funds for the Central Universities(30920032101)Open Research Fund of Jiangsu Key Laboratory of Spectral Imaging&Intelligent Sense(JSGP202105,JSGP202201).
文摘Quantitative phase imaging(QPI)has emerged as a valuable tool for biomedical research thanks to its unique capabilities for quantifying optical thickness variation of living cells and tissues.Among many QPI methods,Fourier ptychographic microscopy(FPM)allows long-term label-free observation and quantitative analysis of large cell populations without compromising spatial and temporal resolution.However,high spatio-temporal resolution imaging over a long-time scale(from hours to days)remains a critical challenge:optically inhomogeneous structure of biological specimens as well as mechanical perturbations and thermal fluctuations of the microscope body all result in time-varying aberration and focus drifts,significantly degrading the imaging performance for long-term study.Moreover,the aberrations are sample-and environmentdependent,and cannot be compensated by a fixed optical design,thus necessitating rapid dynamic correction in the imaging process.Here,we report an adaptive optical QPI method based on annular illumination FPM.In this method,the annular matched illumination configuration(i.e.,the illumination numerical aperture(NA)strictly equals to the objective NA),which is the key for recovering low-frequency phase information,is further utilized for the accurate imaging aberration characterization.By using only 6 low-resolution images captured with 6 different illumination angles matching the NA of a 10x,0.4 NA objective,we recover high-resolution quantitative phase images(synthetic NA of 0.8)and characterize the aberrations in real time,restoring the optimum resolution of the system adaptively.Applying our method to live-cell imaging,we achieve diffraction-limited performance(full-pitch resolution of 655 nm at a wavelength of 525 nm)across a wide field of view(1.77mm2)over an extended period of time.
基金Supported by the State Key Project for Fundamental Research(2012CB825801)National Natural Science Foundation of China(11475170,11205157 and 11179004)Anhui Provincial Natural Science Foundation(1508085MA20)
文摘Since the invention of Zernike phase contrast method in 1930,it has been widely used in optical microscopy and more recently in X-ray microscopy.Considering the image contrast is a mixture of absorption and phase information,we recently have proposed and demonstrated a method for quantitative phase retrieval in Zernike phase contrast X-ray microscopy.In this contribution,we analyze the performance of this method at different photon energies.Intensity images of PMMA samples are simulated at 2.5 keV and 6.2 keV,respectively,and phase retrieval is performed using the proposed method.The results demonstrate that the proposed phase retrieval method is applicable over a wide energy range.For weakly absorbing features,the optimal photon energy is 2.5 keV,from the point of view of image contrast and accuracy of phase retrieval.On the other hand,in the case of strong absorption objects,a higher photon energy is preferred to reduce the error of phase retrieval.These results can be used as guidelines to perform quantitative phase retrieval in Zernike phase contrast X-ray microscopy with the proposed method.
基金supported by the Samsung Research Funding&Incubation Center of Samsung Electronics under Project SRFC-IT2002-07the National Research Foundation of Korea(NRF)Grant funded by the government of Korea(MSIT)(2023R1A2C3004040)+3 种基金the Korea Institute for Advancement of Technology(KIAT)Grant funded by the government of Korea(MOTIE)(P0019784)the Ministry of Science and ICT(Project 2023-22030004-20)(NTIS,1711179106)the Commercialization Promotion Agency for R&D Outcomes(COMPA)funded by the Ministry of Science and ICT(MSIT)(1711198541,development of key optical technologies of inspection and measurement for the analysis of 3D complex nanostructures)the Korea Medical Device Development Fund(KMDF_PR_20200901_0099,Project Number:9991007255).
文摘Red blood cell(RBC)indices serve as clinically important parameters for diagnosing various blood-related diseases.Conventional hematology analyzers provide the highly accurate detection of RBC indices but require large blood volumes(>1 mL),and the results are bulk mean values averaged over a large number of RBCs.Moreover,they do not provide quantitative information related to the morphological and chemical alteration of RBCs at the single-cell level.Recently,quantitative phase imaging(QPI)methods have been introduced as viable detection platforms for RBC indices.However,coherent QPI methods are built on complex optical setups and suffer from coherent speckle noise,which limits their detection accuracy and precision.Here,we present spectroscopic differential phase-contrast(sDPC)microscopy as a platform for measuring RBC indices.sDPC is a computational microscope that produces color-dependent phase images with higher spatial resolution and reduced speckle noise compared to coherent QPIs.Using these spectroscopic phase images and computational algorithms,RBC indices can be extracted with high accuracy.We experimentally demonstrate that sDPC enables the high-accuracy measurement of the mean corpuscular hemoglobin concentration,mean corpuscular volume,mean corpuscular hemoglobin,red cell distribution width,hematocrit,hemoglobin concentration,and RBC count with errors smaller than 7%as compared to a clinical hematology analyzer based on flow cytometry(XN-2000;Sysmex,Kobe,Japan).We further validate the clinical utility of the sDPC method by measuring and comparing the RBC indices of the control and anemic groups against those obtained using the clinical hematology analyzer.
基金supported by the National Key Basic Research Program of China(Grant No.2019YFA0308500,2020YFA0309100,and 2021YFA1400701)the National Natural Science Foundation of China(Grant No.12174437,No.12222414,No.12074416,and No.12104054)+4 种基金the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB33030200)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.Y2022003)the China Postdoctoral Innovative Talent Support Program(Grant No.BX20240409)the China Postdoctoral Science Foundation(Grant No.2024M763507)the Beijing Natural Science Foundation(Grant No.1222035).
文摘Antiferromagnetism has become a promising candidate for the next generation electronic devices due to its thermal stability,low energy consumption,and fast switching speed.However,the canceling of the net magnetic moment in antiferromagnetic order presents great challenge on quantitative characterization and modulation,hindering its investigation and application.In this work,utilizing the optical second harmonic generation(SHG)in a wide temperature range,the integrated differential phase contrast scanning transmission electron microscopy,and firstprinciples calculations,we performed a quantitative study on the evolution of non-collinear antiferromagnetic order in BiFeO_(3)films with a series of strains.We found that the antiferromagnetic coupling was significantly enhanced,featured by the increase of Néel temperature from 428 K to 646 K,and by one order of enhancement of SHG intensity contributed from the G-type antiferromagnetic order by strain manipulation from-2.4%to+0.6%.We attributed the enhancement of the antiferromagnetic coupling to the enhancement of the superexchange interaction as the Fe-O-Fe bond angle approaches 180°when the in-plane lattice constants increase,which might also result in a tendency from a non-collinear antiferromagnetic order to a collinear one.Our work not only bridges the antiferromagnetic order and the strain manipulation in epitaxial multiferroics,more importantly,also paves a way for quantitative characterization by SHG technology and the precise manipulation of antiferromagnetism.
基金supported by the National Natural Science Foundation of China(62227818,62105151,62175109,U21B2033,62105156,62361136588)National Key Research and Development Program of China(2022YFA1205002)+7 种基金Leading Technology of Jiangsu Basic Research Plan(BK20192003)Youth Foundation of Jiangsu Province(BK20210338)Biomedical Competition Foundation of Jia-ngsu Province(BE2022847)Key National Industrial Technology Cooperation Foundation of Jiangsu Province(BZ2022039)Fundamental Research Funds for the Central Universities(30920032101,30923010206)Fundamental Scientific Research Business Fee Funds for the Central Universities(2023102001)Open Research Fund of Jiangsu Key Laboratory of Spectral Imaging&Intelligent Sense(JSGP202105,JSGP202201)National Science Center,Poland(2020/37/B/ST7/03629).
文摘The transport of intensity equation(TIE)is a well-established phase retrieval technique that enables incoherent diffraction limit-resolution imaging and is compatible with widely available brightfield microscopy hardware.However,existing TIE methods encounter difficulties in decoupling the independent contributions of phase and aberrations to the measurements in the case of unknown pupil function.Additionally,spatially nonuniform and temporally varied aberrations dramatically degrade the imaging performance for long-term research.Hence,it remains a critical challenge to realize the high-throughput quantitative phase imaging(QPI)with aberration correction under partially coherent illumination.To address these issues,we propose a novel method for highthroughput microscopy with annular illumination,termed as transport-of-intensity QPI with aberration correction(TI-AC).By combining aberration correction and pixel super-resolution technique,TI-AC is made compatible with large pixel-size sensors to enable a broader field of view.Furthermore,it surpasses the theoretical Nyquist-Shannon sampling resolution limit,resulting in an improvement of more than two times.Experimental results demonstrate that the half-width imaging resolution can be improved to~345 nm across a 10×field of view of 1.77 mm^(2)(0.4 NA).Given its high-throughput capability for QPI,TI-AC is expected to be adopted in biomedical fields,such as drug discovery and cancer diagnostics.
基金We acknowledge financial support from Hong Kong Innovation and Technology Fund(Nos.ITS/394/17 and ITS/098/18FP)Shun Hing Institute of Advanced Engineering(No.BME-p3-18)Croucher Innovation Awards 2019,and the U.S.National Institutes of Health(No.5P41EB015871-33).
文摘A new optical microscopy technique,termed high spatial and temporal resolution synthetic aperture phase microscopy(HISTR-SAPM),is proposed to improve the lateral resolution of wide-field coherent imaging.Under plane wave illumination,the resolution is increased by twofold to around 260 nm,while achieving millisecond-level temporal resolution.In HISTR-SAPM,digital micromirror devices are used to actively change the sample illumination beam angle at high speed with high stability.An off-axis interferometer is used to measure the sample scattered complex fields,which are then processed to reconstruct high-resolution phase images.Using HISTR-SAPM,we are able to map the height profiles of subwavelength photonic structures and resolve the period structures that have 198 nm linewidth and 132 nm gap(i.e.,a full pitch of 330 nm).As the reconstruction averages out laser speckle noise while maintaining high temporal resolution,HISTR-SAPM further enables imaging and quantification of nanoscale dynamics of live cells,such as red blood cell membrane fluctuations and subcellular structure dynamics within nucleated cells.We envision that HISTR-SAPM will broadly benefit research in material science and biology.
