In January 2015,the first quantum homomorphic signature scheme was proposed creatively.However,only one verifier is allowed to verify a signature once in this scheme.In order to support repeatable verification for gen...In January 2015,the first quantum homomorphic signature scheme was proposed creatively.However,only one verifier is allowed to verify a signature once in this scheme.In order to support repeatable verification for general scenario,we propose a new quantum homomorphic signature scheme with repeatable verification by introducing serial verification model and parallel verification model.Serial verification model solves the problem of signature verification by combining key distribution and Bell measurement.Parallel verification model solves the problem of signature duplication by logically treating one particle of an EPR pair as a quantum signature and physically preparing a new EPR pair.These models will be beneficial to the signature verification of general scenarios.Scheme analysis shows that both intermediate verifiers and terminal verifiers can successfully verify signatures in the same operation with fewer resource consumption,and especially the verified signature in entangled states can be used repeatedly.展开更多
Laser-induced damage(LID)on high-power laser facilities is one of the limiting factors for the increase in power and energy.Inertial confinement fusion(ICF)facilities such as Laser Mégajoule or the National Ignit...Laser-induced damage(LID)on high-power laser facilities is one of the limiting factors for the increase in power and energy.Inertial confinement fusion(ICF)facilities such as Laser Mégajoule or the National Ignition Facility use spectral broadening of the laser pulse that may induce power modulations because of frequency modulation to amplitude modulation conversion.In this paper,we study the impact of low and fast power modulations of laser pulses both experimentally and numerically.The MELBA experimental testbed was used to shape a wide variety of laser pulses and to study their impact on LID.A 1D Lagrangian hydrodynamic code was used to understand the impact of different power profiles on LID.展开更多
In this paper we demonstrated a method to reconstruct vector-valued lattice distortion fields within nanoscale crystals by optimization of a forward model of multi-reflection Bragg coherent diffraction imaging(MR-BCDI...In this paper we demonstrated a method to reconstruct vector-valued lattice distortion fields within nanoscale crystals by optimization of a forward model of multi-reflection Bragg coherent diffraction imaging(MR-BCDI)data.The method flexibly accounts for geometric factors that arise when making BCDI measurements,is amenable to efficient inversion with modern optimization toolkits,and allows for globally constraining a single image reconstruction to multiple Bragg peak measurements.This is enabled by a forward model that emulates the multiple Bragg peaks of a MR-BCDI experiment from a single estimate of the 3D crystal sample.We present this forward model,we implement it within the stochastic gradient descent optimization framework,and we demonstrate it with simulated and experimental data of nanocrystals with inhomogeneous internal lattice displacement.We find that utilizing a global optimization approach to MR-BCDI affords a reliable path to convergence of data which is otherwise challenging to reconstruct.展开更多
Coherent Raman scattering microscopy is a fast,label-free,and chemically specific imaging technique that shows high potential for future in vivo optical histology.However,the imaging depth in tissues is limited to the...Coherent Raman scattering microscopy is a fast,label-free,and chemically specific imaging technique that shows high potential for future in vivo optical histology.However,the imaging depth in tissues is limited to the sub-millimeter range because of absorption and scattering.Realization of coherent Raman imaging using a fiber endoscope system is a crucial step towards imaging deep inside living tissues and providing information that is inaccessible with current microscopy tools.Until now,the development of coherent Raman endoscopy has been hampered by several issues,mainly related to the fiber delivery of the excitation pulses and signal collection.Here,we present a flexible,compact,coherent Raman,and multimodal nonlinear endoscope(4.2mm outer diameter,71mm rigid length)based on a resonantly scanned hollow-core Kagomé-lattice double-clad fiber.The fiber design enables distortion-less,background-free delivery of femtosecond excitation pulses and back-collection of nonlinear signals through the same fiber.Sub-micrometer spatial resolution over a large field of view is obtained by combination of a miniature objective lens with a silica microsphere lens inserted into the fiber core.We demonstrate high-resolution,high-contrast coherent anti-Stokes Raman scattering,and second harmonic generation endoscopic imaging of biological tissues over a field of view of 320μm at a rate of 0.8 frames per second.These results pave the way for intraoperative label-free imaging applied to real-time histopathology diagnosis and surgery guidance.展开更多
Light absorption and scattering of plasmonic metal nanoparticles can lead to non-equilibrium charge carriers,intense electromagnetic near-fields,and heat generation,with promising applications in a vast range of field...Light absorption and scattering of plasmonic metal nanoparticles can lead to non-equilibrium charge carriers,intense electromagnetic near-fields,and heat generation,with promising applications in a vast range of fields,from chemical and physical sensing to nanomedicine and photocatalysis for the sustainable production of fuels and chemicals.Disentangling the relative contribution of thermal and non-thermal contributions in plasmon-driven processes is,however,difficult.Nanoscale temperature measurements are technically challenging,and macroscale experiments are often characterized by collective heating effects,which tend to make the actual temperature increase unpredictable.This work is intended to help the reader experimentally detect and quantify photothermal effects in plasmon-driven chemical reactions,to discriminate their contribution from that due to photochemical processes and to cast a critical eye on the current literature.To this aim,we review,and in some cases propose,seven simple experimental procedures that do not require the use of complex or expensive thermal microscopy techniques.These proposed procedures are adaptable to a wide range of experiments and fields of research where photothermal effects need to be assessed,such as plasmonic-assisted chemistry,heterogeneous catalysis,photovoltaics,biosensing,and enhanced molecular spectroscopy.展开更多
Scanning fluorescence microscopes are now able to image large biological samples at high spatial and temporal resolution.This comes at the expense of an increased light dose which is detrimental to fluorophore stabili...Scanning fluorescence microscopes are now able to image large biological samples at high spatial and temporal resolution.This comes at the expense of an increased light dose which is detrimental to fluorophore stability and cell physiology.To highly reduce the light dose,we designed an adaptive scanning fluorescence microscope with a scanning scheme optimized for the unsupervised imaging of cell sheets,which underly the shape of many embryos and organs.The surface of the tissue is first delineated from the acquisition of a very small subset(~0.1%)of sample space,using a robust estimation strategy.Two alternative scanning strategies are then proposed to image the tissue with an improved photon budget,without loss in resolution.The first strategy consists in scanning only a thin shell around the estimated surface of interest,allowing high reduction of light dose when the tissue is curved.The second strategy applies when structures of interest lie at the cell periphery(e.g.adherens junctions).An iterative approach is then used to propagate scanning along cell contours.We demonstrate the benefit of our approach imaging live epithelia from Drosophila melanogaster.On the examples shown,both approaches yield more than a 20-fold reduction in light dose-and up to more than 80-fold-compared to a full scan of the volume.These smart-scanning strategies can be easily implemented on most scanning fluorescent imaging modality.The dramatic reduction in light exposure of the sample should allow prolonged imaging of the live processes under investigation.展开更多
Postoperative visual acuity can be limited by post-keratoplasty astigmatism,even with a clear corneal graft.Astigmatism management can be performed by selective suture removal,adjustment of sutures,optical correction,...Postoperative visual acuity can be limited by post-keratoplasty astigmatism,even with a clear corneal graft.Astigmatism management can be performed by selective suture removal,adjustment of sutures,optical correction,photorefractive procedures,wedge resection,intra-ocular lens implantation,intracorneal ring segments,relaxing incisions with or without compression sutures and repeated keratoplasty.Relaxing incisions can be made in the graft,graft-host interface or host cornea.Despite the unpredictability of the method because the flat and steep meridians are usually not orthogonal after penetrating keratoplasty,with asymmetric power distribution,all the studies showed an overall reduction of refractive,keratometric or topographic astigmatism,ranging from 30%to 72%with manual or femtosecond-assisted techniques.Most patients with astigmatism higher than 6 diopters had residual cylinder less than or equal to 3 diopters,which can be treated by laser excimer ablation or secondary intraocular lens implantation.展开更多
Noninvasive and ultra-accurate optical manipulation of nanometer objects has recently gained interest as a powerful tool in nanotechnology and biophysics.Self-induced back-action(SIBA)trapping in nano-optical cavities...Noninvasive and ultra-accurate optical manipulation of nanometer objects has recently gained interest as a powerful tool in nanotechnology and biophysics.Self-induced back-action(SIBA)trapping in nano-optical cavities has the unique potential for trapping and manipulating nanometer-sized objects under low optical intensities.However,thus far,the existence of the SIBA effect has been shown only indirectly via its enhanced trapping performances.In this article,we present the first time direct experimental evidence of the self-reconfiguration of the optical potential that is experienced by a nanoparticle trapped in a plasmonic nanocavity.Our observations enable us to gain further understanding of the SIBA mechanism and to determine the optimal conditions for boosting the performances of SIBA-based nano-optical tweezers.展开更多
Combining polarization modulation Fourier analysis and spatial information in a joint reconstruction algorithm for polarization-resolved fluorescence imaging provides not only a gain in spatial resolution but also a s...Combining polarization modulation Fourier analysis and spatial information in a joint reconstruction algorithm for polarization-resolved fluorescence imaging provides not only a gain in spatial resolution but also a sensitive readout of anisotropy in cell samples.展开更多
Investigations of ultrafast processes occurring on the nanoscale require a combination of femtosecond pulses and nanometer spatial resolution.However,controlling femtosecond pulses with nanometer accuracy is very chal...Investigations of ultrafast processes occurring on the nanoscale require a combination of femtosecond pulses and nanometer spatial resolution.However,controlling femtosecond pulses with nanometer accuracy is very challenging,as the limitations imposed both by dispersive optics on the time duration of a pulse and by the spatial diffraction limit on the focusing of light must be overcome simultaneously.In this paper,we provide a universal method that allows full femtosecond pulse control in subdiffraction-limited areas.We achieve this aim by exploiting the intrinsic coherence of the second harmonic emission from a single nonlinear nanoparticle of deep subwavelength dimensions.The method is proven to be highly sensitive,easy to use,quick,robust and versatile.This approach allows measurements of minimal phase distortions and the delivery of tunable higher harmonic light in a nanometric volume.Moreover,the method is shown to be compatible with a wide range of particle sizes,shapes and materials,allowing easy optimization for any given sample.This method will facilitate the investigation of light–matter interactions on the femtosecond–nanometer level in various areas of scientific study.展开更多
New 4^(th)-generation synchrotron sources,with their increased bilince,promise to greatly improve the performances of coherent X-ray microscopy.This perspective is of major interest for crystal microscopy,which aims a...New 4^(th)-generation synchrotron sources,with their increased bilince,promise to greatly improve the performances of coherent X-ray microscopy.This perspective is of major interest for crystal microscopy,which aims at revealing the 3D crystalline structure of matter at the nanoscale,an approach strongly limited by the available coherent flux.Our results,based on Bragg ptychography experiments performed at the frst 4-generation synchrotron source,demonstrate the possibility of retrieving a high-quality image of the crystalline sample,with unprecedented quality.Importantly,the larger available coherent flux produces datasets with enough information to overcome experimental limitations,such as strongly deteriorated scanning conditions.We show this achievement would not be posible with 30-generation sources,a limit that has inhibited the development of this otherwise powerful microscopy method,so far.Hence,the advent of next-generation synchrotron sources not only makes Bragg ptychography suitable for high throughput studies but also strongly relaxes the associated experimental constraints,making it compatible with a wider range of experimental set-ups at the new synchrotrons.展开更多
基金This project was supported by the National Natural Science Foundation of China(No.61571024)the National Key Research and Development Program of China(No.2016YFC1000307)for valuable helps.
文摘In January 2015,the first quantum homomorphic signature scheme was proposed creatively.However,only one verifier is allowed to verify a signature once in this scheme.In order to support repeatable verification for general scenario,we propose a new quantum homomorphic signature scheme with repeatable verification by introducing serial verification model and parallel verification model.Serial verification model solves the problem of signature verification by combining key distribution and Bell measurement.Parallel verification model solves the problem of signature duplication by logically treating one particle of an EPR pair as a quantum signature and physically preparing a new EPR pair.These models will be beneficial to the signature verification of general scenarios.Scheme analysis shows that both intermediate verifiers and terminal verifiers can successfully verify signatures in the same operation with fewer resource consumption,and especially the verified signature in entangled states can be used repeatedly.
文摘Laser-induced damage(LID)on high-power laser facilities is one of the limiting factors for the increase in power and energy.Inertial confinement fusion(ICF)facilities such as Laser Mégajoule or the National Ignition Facility use spectral broadening of the laser pulse that may induce power modulations because of frequency modulation to amplitude modulation conversion.In this paper,we study the impact of low and fast power modulations of laser pulses both experimentally and numerically.The MELBA experimental testbed was used to shape a wide variety of laser pulses and to study their impact on LID.A 1D Lagrangian hydrodynamic code was used to understand the impact of different power profiles on LID.
基金The development of the MR-BCDI forward model and inversion approach,experimental demonstration,and design and fabrication of the SiC nanoparticles was supported by the U.S.Department of Energy(DOE),Office of Science,Basic Energy Sciences,Materials Science and Engineering Division.Additional support for materials preparation came from the Q-NEXT Quantum Center,a U.S.Department of Energy,Office of Science,National Quantum Information Science Research Center,under Award Number DE-FOA-0002253Silicon carbide deterministic nanoparticle fabrication and SEM characterization work was performed under proposals 72483 and 775514 in the Center for Nanoscale Materials clean room.Work performed at the Center for Nanoscale Materials,a U.S+3 种基金Department of Energy Office of Science User Facility,was supported by the U.S.DOE,Office of Basic Energy Sciences,under Contract No.DE-AC02-06CH11357Refinement of the geometric,computational and optimization concepts was supported by the European Research Council(European Union’s Horizon H2020 research and innovation program grant agreement No.724881).Generation of the simulated structures and the BCDI data acquisition was supported by the Laboratory Directed Research and Development(LDRD)funding from Argonne National Laboratory,provided by the Director,Office of Science,of the U.S.Department of Energy under Contract No.DE-AC02-06CH11357This research uses the resources of the Advanced Photon Source,a U.S.DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under contract No.DE-AC02-06CH11357The authors gratefully acknowledge numerous valuable discussions with Drs.Anthony Rollett,Robert Suter and Matthew Wilkin(Carnegie Mellon University),Nicholas Porter and Dr.Richard Sandberg(Brigham Young University),Dr.Ross Harder(Argonne National Laboratory)and Dr.Anastasios Pateras(DESY).The authors gratefully acknowledge numerous valuable discussions and experimental guidance from Dr.David A.Czaplewski,Suzanne Miller,and Dr.Ralu Divan of the Center of Nanoscale Materials.
文摘In this paper we demonstrated a method to reconstruct vector-valued lattice distortion fields within nanoscale crystals by optimization of a forward model of multi-reflection Bragg coherent diffraction imaging(MR-BCDI)data.The method flexibly accounts for geometric factors that arise when making BCDI measurements,is amenable to efficient inversion with modern optimization toolkits,and allows for globally constraining a single image reconstruction to multiple Bragg peak measurements.This is enabled by a forward model that emulates the multiple Bragg peaks of a MR-BCDI experiment from a single estimate of the 3D crystal sample.We present this forward model,we implement it within the stochastic gradient descent optimization framework,and we demonstrate it with simulated and experimental data of nanocrystals with inhomogeneous internal lattice displacement.We find that utilizing a global optimization approach to MR-BCDI affords a reliable path to convergence of data which is otherwise challenging to reconstruct.
基金supported by EU-ITN-607842-2013-FINON,FR-“Investissement d’Avenir”-11-IDEX-0001-02,11-INSB-0006,11-EQPX-0017,11-LABX-0007,FR-ANR-14-CE17-0004-01,FR-INSERM-PC201508,EU Regional Development Fund(ERDF)Centre National de la Recherche Scientifique(IRCICA USR 3380)the Chinese Science Council(China)for funding support.
文摘Coherent Raman scattering microscopy is a fast,label-free,and chemically specific imaging technique that shows high potential for future in vivo optical histology.However,the imaging depth in tissues is limited to the sub-millimeter range because of absorption and scattering.Realization of coherent Raman imaging using a fiber endoscope system is a crucial step towards imaging deep inside living tissues and providing information that is inaccessible with current microscopy tools.Until now,the development of coherent Raman endoscopy has been hampered by several issues,mainly related to the fiber delivery of the excitation pulses and signal collection.Here,we present a flexible,compact,coherent Raman,and multimodal nonlinear endoscope(4.2mm outer diameter,71mm rigid length)based on a resonantly scanned hollow-core Kagomé-lattice double-clad fiber.The fiber design enables distortion-less,background-free delivery of femtosecond excitation pulses and back-collection of nonlinear signals through the same fiber.Sub-micrometer spatial resolution over a large field of view is obtained by combination of a miniature objective lens with a silica microsphere lens inserted into the fiber core.We demonstrate high-resolution,high-contrast coherent anti-Stokes Raman scattering,and second harmonic generation endoscopic imaging of biological tissues over a field of view of 320μm at a rate of 0.8 frames per second.These results pave the way for intraoperative label-free imaging applied to real-time histopathology diagnosis and surgery guidance.
基金support by the Dutch Research Council(Nederlandse Organisatie voor Wetenschappelijk Onderzoek)via the NWO Vidi award 680-47-550.
文摘Light absorption and scattering of plasmonic metal nanoparticles can lead to non-equilibrium charge carriers,intense electromagnetic near-fields,and heat generation,with promising applications in a vast range of fields,from chemical and physical sensing to nanomedicine and photocatalysis for the sustainable production of fuels and chemicals.Disentangling the relative contribution of thermal and non-thermal contributions in plasmon-driven processes is,however,difficult.Nanoscale temperature measurements are technically challenging,and macroscale experiments are often characterized by collective heating effects,which tend to make the actual temperature increase unpredictable.This work is intended to help the reader experimentally detect and quantify photothermal effects in plasmon-driven chemical reactions,to discriminate their contribution from that due to photochemical processes and to cast a critical eye on the current literature.To this aim,we review,and in some cases propose,seven simple experimental procedures that do not require the use of complex or expensive thermal microscopy techniques.These proposed procedures are adaptable to a wide range of experiments and fields of research where photothermal effects need to be assessed,such as plasmonic-assisted chemistry,heterogeneous catalysis,photovoltaics,biosensing,and enhanced molecular spectroscopy.
基金This work was funded by the following agencies:Agence Nationale de la Recherche(ANR-18-CE13-028,ANR-17-CE30-0007)Excellence Initiative of Aix-Marseille University-A*Midex(capostromex),a French Investissements d’Avenir programme+4 种基金Centre National de la Recherche Scientifique,Mission pour l’InterdisciplinariteInstitut Carnot starSATT-SudEstThe project leading to this publication has received funding from the“Investissements d’Avenir”French Government program managed by the French National Research Agency(ANR-16-CONV-0001)from Excellence Initiative of Aix-Marseille University-A*MIDEX.
文摘Scanning fluorescence microscopes are now able to image large biological samples at high spatial and temporal resolution.This comes at the expense of an increased light dose which is detrimental to fluorophore stability and cell physiology.To highly reduce the light dose,we designed an adaptive scanning fluorescence microscope with a scanning scheme optimized for the unsupervised imaging of cell sheets,which underly the shape of many embryos and organs.The surface of the tissue is first delineated from the acquisition of a very small subset(~0.1%)of sample space,using a robust estimation strategy.Two alternative scanning strategies are then proposed to image the tissue with an improved photon budget,without loss in resolution.The first strategy consists in scanning only a thin shell around the estimated surface of interest,allowing high reduction of light dose when the tissue is curved.The second strategy applies when structures of interest lie at the cell periphery(e.g.adherens junctions).An iterative approach is then used to propagate scanning along cell contours.We demonstrate the benefit of our approach imaging live epithelia from Drosophila melanogaster.On the examples shown,both approaches yield more than a 20-fold reduction in light dose-and up to more than 80-fold-compared to a full scan of the volume.These smart-scanning strategies can be easily implemented on most scanning fluorescent imaging modality.The dramatic reduction in light exposure of the sample should allow prolonged imaging of the live processes under investigation.
文摘Postoperative visual acuity can be limited by post-keratoplasty astigmatism,even with a clear corneal graft.Astigmatism management can be performed by selective suture removal,adjustment of sutures,optical correction,photorefractive procedures,wedge resection,intra-ocular lens implantation,intracorneal ring segments,relaxing incisions with or without compression sutures and repeated keratoplasty.Relaxing incisions can be made in the graft,graft-host interface or host cornea.Despite the unpredictability of the method because the flat and steep meridians are usually not orthogonal after penetrating keratoplasty,with asymmetric power distribution,all the studies showed an overall reduction of refractive,keratometric or topographic astigmatism,ranging from 30%to 72%with manual or femtosecond-assisted techniques.Most patients with astigmatism higher than 6 diopters had residual cylinder less than or equal to 3 diopters,which can be treated by laser excimer ablation or secondary intraocular lens implantation.
基金support from the FundacióPrivada Cellex,the Severo Ochoa program,the Spanish Ministry of Economy and Competitiveness(grant FPU-AP-2012-3729 and FIS2013-46141-P)the European Research Council through Consolidator grant QnanoMECA(#64790).
文摘Noninvasive and ultra-accurate optical manipulation of nanometer objects has recently gained interest as a powerful tool in nanotechnology and biophysics.Self-induced back-action(SIBA)trapping in nano-optical cavities has the unique potential for trapping and manipulating nanometer-sized objects under low optical intensities.However,thus far,the existence of the SIBA effect has been shown only indirectly via its enhanced trapping performances.In this article,we present the first time direct experimental evidence of the self-reconfiguration of the optical potential that is experienced by a nanoparticle trapped in a plasmonic nanocavity.Our observations enable us to gain further understanding of the SIBA mechanism and to determine the optimal conditions for boosting the performances of SIBA-based nano-optical tweezers.
文摘Combining polarization modulation Fourier analysis and spatial information in a joint reconstruction algorithm for polarization-resolved fluorescence imaging provides not only a gain in spatial resolution but also a sensitive readout of anisotropy in cell samples.
基金This research was funded by the MICINN(programs Consolider Ingenio-2010:CSD2007-046-NanoLight.es,Plan Nacional FIS2009-0123:Optical NanoAntennas)the European Union(ERC Advanced Grant 247330-NanoAntennas)+2 种基金LP acknowledges financial support from the Marie-Curie International Fellowship COFUND and ICFOnest programFP received support from the European Commission through the Erasmus Mundus Joint Doctorate Programme Europhotonics(Grant No.159224-1-2009-1-FR-ERA MUNDUS-EMJD)DB acknowledges support from a Rubicon Grant of the Netherlands Organization for Scientific Research.
文摘Investigations of ultrafast processes occurring on the nanoscale require a combination of femtosecond pulses and nanometer spatial resolution.However,controlling femtosecond pulses with nanometer accuracy is very challenging,as the limitations imposed both by dispersive optics on the time duration of a pulse and by the spatial diffraction limit on the focusing of light must be overcome simultaneously.In this paper,we provide a universal method that allows full femtosecond pulse control in subdiffraction-limited areas.We achieve this aim by exploiting the intrinsic coherence of the second harmonic emission from a single nonlinear nanoparticle of deep subwavelength dimensions.The method is proven to be highly sensitive,easy to use,quick,robust and versatile.This approach allows measurements of minimal phase distortions and the delivery of tunable higher harmonic light in a nanometric volume.Moreover,the method is shown to be compatible with a wide range of particle sizes,shapes and materials,allowing easy optimization for any given sample.This method will facilitate the investigation of light–matter interactions on the femtosecond–nanometer level in various areas of scientific study.
基金the European Research Council(European Union’s Horizon H2020 research and innovation program grant agreements No 724881Research conducted at MAX IV is supported by the Swedish Research Council under Contract 2018-07152the Swedish Governmental Agency for Innovation Systems under Contract 2018-04969,and Formas under Contraa 2019-02496.
文摘New 4^(th)-generation synchrotron sources,with their increased bilince,promise to greatly improve the performances of coherent X-ray microscopy.This perspective is of major interest for crystal microscopy,which aims at revealing the 3D crystalline structure of matter at the nanoscale,an approach strongly limited by the available coherent flux.Our results,based on Bragg ptychography experiments performed at the frst 4-generation synchrotron source,demonstrate the possibility of retrieving a high-quality image of the crystalline sample,with unprecedented quality.Importantly,the larger available coherent flux produces datasets with enough information to overcome experimental limitations,such as strongly deteriorated scanning conditions.We show this achievement would not be posible with 30-generation sources,a limit that has inhibited the development of this otherwise powerful microscopy method,so far.Hence,the advent of next-generation synchrotron sources not only makes Bragg ptychography suitable for high throughput studies but also strongly relaxes the associated experimental constraints,making it compatible with a wider range of experimental set-ups at the new synchrotrons.