Sea topography information holds significant importance in oceanic research and the climate change detection.Radar imaging altimetry has emerged as the leading approach for global ocean observation,employing synthetic...Sea topography information holds significant importance in oceanic research and the climate change detection.Radar imaging altimetry has emerged as the leading approach for global ocean observation,employing synthetic aperture radar(SAR)interferometry to enhance the spatial resolution of Sea topography.Nevertheless,current payload capacity and satellite hardware limitations prevent the extension of the interferometric baseline by enlarging the physical antenna size.This constraint hinders achieving centimeter-level accuracy in interferometric altimetry.To address this challenge,we conducted a numerical simulation to assess the viability of a large baseline interferometric imaging altimeter(LB-IIA).By controlling the baseline within the range of 600-1000 m through spiral orbit design in two satellites and mitigating baseline de-correlation with the carrier frequency shift(CFS)technique,we aimed to overcome the above limitations.Our findings demonstrate the efficacy of the CFS technique in compensating for baseline decoherence,elevating coherence from less than 0.1 to over 0.85.Concurrently.The height difference accuracy between neighboring sea surfaces reaches 1 cm within a 1 km resolution.This study is anticipated to serve as a foundational reference for future interferometric imaging altimeter development,catering to the demand for high-precision sea topography data in accurate global bathymetry inversion.展开更多
Knowledge of the locations of seismic sources is critical for microseismic monitoring. Time-window-based elastic wave interferometric imaging and weighted- elastic-wave （WEW） interferometric imaging are proposed and...Knowledge of the locations of seismic sources is critical for microseismic monitoring. Time-window-based elastic wave interferometric imaging and weighted- elastic-wave （WEW） interferometric imaging are proposed and used to locate modeled microseismic sources. The proposed method improves the precision and eliminates artifacts in location profiles. Numerical experiments based on a horizontally layered isotropic medium have shown that the method offers the following advantages： It can deal with Iow-SNR microseismic data with velocity perturbations as well as relatively sparse receivers and still maintain relatively high precision despite the errors in the velocity model. Furthermore, it is more efficient than conventional traveltime inversion methods because interferometric imaging does not require traveltime picking. Numerical results using a 2D fault model have also suggested that the weighted-elastic-wave interferometric imaging can locate multiple sources with higher location precision than the time-reverse imaging method.展开更多
Polarization-based detection technologies have broad applications across various fields.Integrating polarization with interferometric imaging holds significant promise for simultaneously capturing three-dimensional st...Polarization-based detection technologies have broad applications across various fields.Integrating polarization with interferometric imaging holds significant promise for simultaneously capturing three-dimensional structure and polarization information.However,existing interferometric polarization measurement methods often rely on complex setups and sacrifice the acquisition rate or axial imaging range for parameter diversity.展开更多
The interferometric particle imaging technique makes use of the angular oscillations of the scattered light in the forward direction for droplet or bubble sizing.The out-of-focus image consists of fringes,the spacing ...The interferometric particle imaging technique makes use of the angular oscillations of the scattered light in the forward direction for droplet or bubble sizing.The out-of-focus image consists of fringes,the spacing of which reflects the interference between the surface-reflected light and the twofold-refracted light.Total internal reflection occurs when the incident light hits the bubble at a large incident angle.The tunneling phase shift is not included in the geometric optics approximation,which leads to a deviation from Mie theory.In this work,we modified the formula for describing the fringe spacing by including the tunneling phase shift of total internal reflection.Numerical analysis and experiments showed that the modification is effective for the measurement of bubbles smaller than 60μm.展开更多
Synthetic aperture interferometric technique has wide applications in optics,radio astronomy and mi-crowave remote sensing areas.With the increasing demands of high resolution imaging observation,a new time-sharing sa...Synthetic aperture interferometric technique has wide applications in optics,radio astronomy and mi-crowave remote sensing areas.With the increasing demands of high resolution imaging observation,a new time-sharing sampling scheme of asynchronous rotation scan is proposed to meet the technical challenge of achieving a large equivalent aperture and overcome the operating barriers of space borne application.This configuration is basically composed by two asynchronously and concentrically ro-tating antenna groups,whose revolving radii and speeds are different.The synthetic aperture system with asynchronous rotation scanning scheme can effectively solve the trade-off problem of system complexity,and greatly simplify the system hardware at the cost of sacrificing a certain time resolution.The basic rules and design methods of asynchronous rotation scan are investigated The Gridding method is introduced to inverse the spiral sampling data for image reconstruction.The potential ap-plications of geostationary orbit(GEO)earth observation and solar polar orbit(SPO)plasma cloud observation are explored with numerical simulations to validate the significance and feasibility of this new imaging configuration.展开更多
Nanophotonics,and more specifically plasmonics,provides a rich toolbox for biomolecular sensing,since the engineered metasurfaces can enhance light–matter interactions to unprecedented levels.So far,biosensing associ...Nanophotonics,and more specifically plasmonics,provides a rich toolbox for biomolecular sensing,since the engineered metasurfaces can enhance light–matter interactions to unprecedented levels.So far,biosensing associated with high-quality factor plasmonic resonances has almost exclusively relied on detection of spectral shifts and their associated intensity changes.However,the phase response of the plasmonic resonances have rarely been exploited,mainly because this requires a more sophisticated optical arrangement.Here we present a new phase-sensitive platform for high-throughput and label-free biosensing enhanced by plasmonics.It employs specifically designed Au nanohole arrays and a large field-of-view interferometric lens-free imaging reader operating in a collinear optical path configuration.This unique combination allows the detection of atomically thin(angstrom-level)topographical features over large areas,enabling simultaneous reading of thousands of microarray elements.As the plasmonic chips are fabricated using scalable techniques and the imaging reader is built with low-cost off-the-shelf consumer electronic and optical components,the proposed platform is ideal for point-of-care ultrasensitive biomarker detection from small sample volumes.Our research opens new horizons for on-site disease diagnostics and remote health monitoring.展开更多
We present a new approach for predicting spatial phase signals originating from photothermally excited metallic nanoparticles of arbitrary shapes and sizes.The heat emitted from such a nanoparticle affects the measure...We present a new approach for predicting spatial phase signals originating from photothermally excited metallic nanoparticles of arbitrary shapes and sizes.The heat emitted from such a nanoparticle affects the measured optical phase signal via changes in both the refractive index and thickness of the nanoparticle surroundings.Because these particles can be bio-functionalized to bind certain biological cell components,they can be used for biomedical imaging with molecular specificity,as new nanoscopy labels,and for photothermal therapy.Predicting the ideal nanoparticle parameters requires a model that computes the thermal and phase distributions around the particle,thereby enabling more efficient phase imaging of plasmonic nanoparticles and avoiding trial-and-error experiments while using unsuitable nanoparticles.The proposed nonlinear model is the first to enable the prediction of phase signatures from nanoparticles with arbitrary parameters.The model is based on a finite-volume method for geometry discretization and an implicit backward Euler method for solving the transient inhomogeneous heat equation,followed by calculation of the accumulative phase signal.To validate the model,we compared its results with experimental results obtained for gold nanorods of various concentrations,which we acquired using a custom-built wide-field interferometric phase microscopy system.展开更多
文摘Sea topography information holds significant importance in oceanic research and the climate change detection.Radar imaging altimetry has emerged as the leading approach for global ocean observation,employing synthetic aperture radar(SAR)interferometry to enhance the spatial resolution of Sea topography.Nevertheless,current payload capacity and satellite hardware limitations prevent the extension of the interferometric baseline by enlarging the physical antenna size.This constraint hinders achieving centimeter-level accuracy in interferometric altimetry.To address this challenge,we conducted a numerical simulation to assess the viability of a large baseline interferometric imaging altimeter(LB-IIA).By controlling the baseline within the range of 600-1000 m through spiral orbit design in two satellites and mitigating baseline de-correlation with the carrier frequency shift(CFS)technique,we aimed to overcome the above limitations.Our findings demonstrate the efficacy of the CFS technique in compensating for baseline decoherence,elevating coherence from less than 0.1 to over 0.85.Concurrently.The height difference accuracy between neighboring sea surfaces reaches 1 cm within a 1 km resolution.This study is anticipated to serve as a foundational reference for future interferometric imaging altimeter development,catering to the demand for high-precision sea topography data in accurate global bathymetry inversion.
基金supported by the R&D of Key Instruments and Technologies for Deep Resources Prospecting(No.ZDYZ2012-1)National Natural Science Foundation of China(No.11374322)
文摘Knowledge of the locations of seismic sources is critical for microseismic monitoring. Time-window-based elastic wave interferometric imaging and weighted- elastic-wave （WEW） interferometric imaging are proposed and used to locate modeled microseismic sources. The proposed method improves the precision and eliminates artifacts in location profiles. Numerical experiments based on a horizontally layered isotropic medium have shown that the method offers the following advantages： It can deal with Iow-SNR microseismic data with velocity perturbations as well as relatively sparse receivers and still maintain relatively high precision despite the errors in the velocity model. Furthermore, it is more efficient than conventional traveltime inversion methods because interferometric imaging does not require traveltime picking. Numerical results using a 2D fault model have also suggested that the weighted-elastic-wave interferometric imaging can locate multiple sources with higher location precision than the time-reverse imaging method.
基金National Natural Science Foundation of China(12404345,62375144)Tianjin Natural Science Foundation(22JCZDJC00160)+1 种基金Fundamental Research Funds for the Central Universities,Nankai University(63241331)China Postdoctoral Science Foundation(2023M731787)。
文摘Polarization-based detection technologies have broad applications across various fields.Integrating polarization with interferometric imaging holds significant promise for simultaneously capturing three-dimensional structure and polarization information.However,existing interferometric polarization measurement methods often rely on complex setups and sacrifice the acquisition rate or axial imaging range for parameter diversity.
基金The work was supported by National Science and Technology Major Project of China(2017-V-0016-0069).
文摘The interferometric particle imaging technique makes use of the angular oscillations of the scattered light in the forward direction for droplet or bubble sizing.The out-of-focus image consists of fringes,the spacing of which reflects the interference between the surface-reflected light and the twofold-refracted light.Total internal reflection occurs when the incident light hits the bubble at a large incident angle.The tunneling phase shift is not included in the geometric optics approximation,which leads to a deviation from Mie theory.In this work,we modified the formula for describing the fringe spacing by including the tunneling phase shift of total internal reflection.Numerical analysis and experiments showed that the modification is effective for the measurement of bubbles smaller than 60μm.
基金Supported by the National Natural Science Foundation of China(Grant No. 40574070,40671121,40701100 and 40801136)the National High-Tech Re-search Program of China("863" Program)(Grant No.2006AA12Z141)
文摘Synthetic aperture interferometric technique has wide applications in optics,radio astronomy and mi-crowave remote sensing areas.With the increasing demands of high resolution imaging observation,a new time-sharing sampling scheme of asynchronous rotation scan is proposed to meet the technical challenge of achieving a large equivalent aperture and overcome the operating barriers of space borne application.This configuration is basically composed by two asynchronously and concentrically ro-tating antenna groups,whose revolving radii and speeds are different.The synthetic aperture system with asynchronous rotation scanning scheme can effectively solve the trade-off problem of system complexity,and greatly simplify the system hardware at the cost of sacrificing a certain time resolution.The basic rules and design methods of asynchronous rotation scan are investigated The Gridding method is introduced to inverse the spiral sampling data for image reconstruction.The potential ap-plications of geostationary orbit(GEO)earth observation and solar polar orbit(SPO)plasma cloud observation are explored with numerical simulations to validate the significance and feasibility of this new imaging configuration.
基金funded by the European Union’s Horizon 2020 research and innovation program under Grant Agreement No.644956(RAIS project)the North Atlantic Treaty Organization’s Public Diplomacy Division in the framework of‘Science for Peace’(NATO—SPS),École Polytechnique Fédérale de Lausanne research fund,FundacióPrivada Cellex+4 种基金the CERCA Programme/Generalitat de Catalunyasupport from the International PhD fellowship program‘la Caixa’—Severo Ochoa@ICFOsupport from the International PhD fellowship program'la Caixa'-Severo Ochoa@ICFOsupport from the Spanish Ministry of Economy and Competitiveness,through the‘Severo Ochoa’Programme for Centres of Excellence in R&D(SEV-2015-0522)project OPTO-SCREEN(TEC2016-75080-R).
文摘Nanophotonics,and more specifically plasmonics,provides a rich toolbox for biomolecular sensing,since the engineered metasurfaces can enhance light–matter interactions to unprecedented levels.So far,biosensing associated with high-quality factor plasmonic resonances has almost exclusively relied on detection of spectral shifts and their associated intensity changes.However,the phase response of the plasmonic resonances have rarely been exploited,mainly because this requires a more sophisticated optical arrangement.Here we present a new phase-sensitive platform for high-throughput and label-free biosensing enhanced by plasmonics.It employs specifically designed Au nanohole arrays and a large field-of-view interferometric lens-free imaging reader operating in a collinear optical path configuration.This unique combination allows the detection of atomically thin(angstrom-level)topographical features over large areas,enabling simultaneous reading of thousands of microarray elements.As the plasmonic chips are fabricated using scalable techniques and the imaging reader is built with low-cost off-the-shelf consumer electronic and optical components,the proposed platform is ideal for point-of-care ultrasensitive biomarker detection from small sample volumes.Our research opens new horizons for on-site disease diagnostics and remote health monitoring.
基金This work was supported by the FP7 Marie Curie Career Integration Grant(CIG)No.303559.
文摘We present a new approach for predicting spatial phase signals originating from photothermally excited metallic nanoparticles of arbitrary shapes and sizes.The heat emitted from such a nanoparticle affects the measured optical phase signal via changes in both the refractive index and thickness of the nanoparticle surroundings.Because these particles can be bio-functionalized to bind certain biological cell components,they can be used for biomedical imaging with molecular specificity,as new nanoscopy labels,and for photothermal therapy.Predicting the ideal nanoparticle parameters requires a model that computes the thermal and phase distributions around the particle,thereby enabling more efficient phase imaging of plasmonic nanoparticles and avoiding trial-and-error experiments while using unsuitable nanoparticles.The proposed nonlinear model is the first to enable the prediction of phase signatures from nanoparticles with arbitrary parameters.The model is based on a finite-volume method for geometry discretization and an implicit backward Euler method for solving the transient inhomogeneous heat equation,followed by calculation of the accumulative phase signal.To validate the model,we compared its results with experimental results obtained for gold nanorods of various concentrations,which we acquired using a custom-built wide-field interferometric phase microscopy system.
