Acoustic-vortex(AV)tweezers ensure stable particle trapping at a zero-pressure center,while particle assembly between two vortex cores is still prevented by the high-potential barrier.Although a one-dimensional low-pr...Acoustic-vortex(AV)tweezers ensure stable particle trapping at a zero-pressure center,while particle assembly between two vortex cores is still prevented by the high-potential barrier.Although a one-dimensional low-pressure attractive path of particle assembly can be constructed by the interference between two independent cylindrical Bessel beams,it remains challenging to create two-dimensional(2D)neighboring vortexes using a source array in practical applications.In this paper,a three-step phase-reversal strategy of 2D particle assembly based on the synchronized evolution of a centrosymmetric array of M off-axis acoustic vortexes(OA-AVs)with a preset radial offset is proposed based on a ring array of planar sources.By introducing initial vortex phase differences of-2π/M and+2π/M to the vortex array,low-pressure patterns of an M-sided regular polygon and M-branched star are formed by connecting the vortex cores and the field center before and after the tangent state of adjacent OA-AVs.Center-oriented particle assembly is finally realized by a central AV constructed by coincident in-phase OA-AVs.The capability of particle manipulation in the lateral and radial directions is demonstrated by low-pressure patterns with acoustic radiation forces pointing to the field center during a synchronized central approach.The field evolution is certified by experimental field measurements for OA-AVs with different vo rtex numbers,initial vortex phase differences,and radial offsets using a ring array of 16 planar sources.The feasibility of particle assembly in two dimensions is also verified by the accurate manipulation of four particles using the low-pressure patterns of a four-sided polygon,a four-branched star,and a central AV in experiments.The three-step strategy paves a new way for 2D particle assembly based on the synchronize d evolution of centrosymmetric OA-AVs using a simplified single-sided source array,exhibiting excellent potential for the precise navigation and manipulation of cells and particles in biomedical applications.展开更多
Phase singularities(PSs)in topological darkness-based sensors have received significant attention in optical sensing due to their rapid,ultra-sensitive,and label-free detection capabilities.Here,we present both experi...Phase singularities(PSs)in topological darkness-based sensors have received significant attention in optical sensing due to their rapid,ultra-sensitive,and label-free detection capabilities.Here,we present both experimental and theoretical investigations of an ultrasensitive and multiplexed phase-sensitive sensor utilizing dual topological PSs in the visible and near-infrared regions.This sensor uses a simple structure,which consists of an ultra-thin highly absorbing film deposited on a metal substrate.We demonstrate the achievement of dual-polarization darkness points for s-and p-polarizations at different incident angles.Furthermore,we theoretically explain the double topological PSs accompanied by a perfect±π-jump near a zero-reflection point,based on the temporal coupled-mode formalism.To validate its multifunctional capabilities,humidity sensing tests were carried out.The results demonstrate that the sensor has a detection limit reaching the level of 0.12‰.These findings go beyond the scope of conventional interference optical coatings and highlight the potential applications of this technology in gas sensing and biosensing domains.展开更多
Detection of small cancer biomarkers with low molecular weight and a low concentration range has always been challenging yet urgent in many clinical applications such as diagnosing early-stage cancer,monitoring treatm...Detection of small cancer biomarkers with low molecular weight and a low concentration range has always been challenging yet urgent in many clinical applications such as diagnosing early-stage cancer,monitoring treatment and detecting relapse.Here,a highly enhanced plasmonic biosensor that can overcome this challenge is developed using atomically thin two-dimensional phase change nanomaterial.By precisely engineering the configuration with atomically thin materials,the phase singularity has been successfully achieved with a significantly enhanced lateral position shift effect.Based on our knowledge,it is the first experimental demonstration of a lateral position signal change>340μm at a sensing interface from all optical techniques.With this enhanced plasmonic effect,the detection limit has been experimentally demonstrated to be 10^(-15) mol L^(−1) for TNF-α cancer marker,which has been found in various human diseases including inflammatory diseases and different kinds of cancer.The as-reported novel integration of atomically thin Ge_(2)Sb_(2)Te_(5) with plasmonic substrate, which results in a phase singularity and thus a giant lateral position shift, enables the detection of cancer markers with low molecular weight at femtomolar level. These results will definitely hold promising potential in biomedical application and clinical diagnostics.展开更多
By using the generalized Debye diffraction integral, this paper studies the spatial correlation properties and phase singularity annihilation of apertured Gaussian Schell-model （GSM） beams in the focal region. It is...By using the generalized Debye diffraction integral, this paper studies the spatial correlation properties and phase singularity annihilation of apertured Gaussian Schell-model （GSM） beams in the focal region. It is shown that the width of the spectral degree of coherence can be larger, less than or equal to the corresponding width of spectral density, which depends not only on the scalar coherence length of the beams, but also on the truncation parameter. With a gradual increase of the truncation parameter, a pair of phase singularities of the spectral degree of coherence in the focal plane approaches each other, resulting in subwavelength structures. Finally, the annihilation of pairs of phase singularities takes place at a certain value of the truncation parameter. With increasing scalar coherence length, the annihilation occurs at the larger truncation parameter. However, the creation process of phase singularities outside the focal plane is not found for GSM beams.展开更多
Photonic devices that exhibit both sensitivity and robustness have long been sought;yet,these characteristics are thought to be mutually exclusive;through sensitivity,a sensor responds to external stimuli,whereas robu...Photonic devices that exhibit both sensitivity and robustness have long been sought;yet,these characteristics are thought to be mutually exclusive;through sensitivity,a sensor responds to external stimuli,whereas robustness embodies the inherent ability of a device to withstand weathering by these same stimuli.This challenge stems from the inherent contradiction between robustness and sensitivity in wave dynamics,which require the coexistence of noise-immune sensitive states and modulation-sensitive transitions between these states.We report and experimentally demonstrate a subwavelength phase singularity in a chiral medium that is resilient to fabrication imperfections and disorder while remaining highly responsive to external stimuli.The combination of subwavelength light confinement and its robustness lays the foundation for the development of hitherto unexplored chip-scale photonics devices,enabling a simultaneous development of high-sensitivity and robust devices in both quantum and classical realms.展开更多
In this paper, we study the topological structure of the singular points of the third order phase locked loop equations with the character of detected phase being g(?) =(1+k)sin?/1+kcos?.
Within the framework of Einstein-Cartan theory,we obtain a general condition leading to singularity and inflation for all Bianchi cosmological models.If the spin energy is smaller than anisotropic energy density(i.e.S...Within the framework of Einstein-Cartan theory,we obtain a general condition leading to singularity and inflation for all Bianchi cosmological models.If the spin energy is smaller than anisotropic energy density(i.e.S^(2)σ^(2)<0),the Universe can not avoid singularity.If S^(2)-σ^(2)>-pv/^(2)(pv is vacuum energy density),the Universe can undergo an inflation phase.Examples of Bianchi type-IX,I and V cosmological models are discussed.展开更多
In this paper,knotted objects (RS vortices) in the theory of topological phase singularity in electromagneticfield have been investigated in details.By using the Duan's topological current theory,we rewrite the to...In this paper,knotted objects (RS vortices) in the theory of topological phase singularity in electromagneticfield have been investigated in details.By using the Duan's topological current theory,we rewrite the topological currentform of RS vortices and use this topological current we reveal that the Hopf invariant of RS vortices is just the sum ofthe linking and self-linking numbers of the knotted RS vortices.Furthermore,the conservation of the Hopf invariant inthe splitting,the mergence and the intersection processes of knotted RS vortices is also discussed.展开更多
Performed in this work are complex statistical,fractal and singular analyses of phase properties inherent to birefringence networks of protein crystals consisting of optically-thin layers prepared from blood plasma.Wi...Performed in this work are complex statistical,fractal and singular analyses of phase properties inherent to birefringence networks of protein crystals consisting of optically-thin layers prepared from blood plasma.Within the framework of a statistical approach,the authors have investigated values and ranges for changes of statistical moments of thefirst to the fourth orders that characterize coordinate distributions for phase shifts between orthogonal components of amplitudes inherent to laser radiation transformed by blood plasma with various pathologies.In the framework of the fractal approach,determined are the dimensions of self-similar coordinate phase distributions as well as features of transformation of logarithmic dependences for power spectra of these distributions for various types of hominal mammary gland pathologies.展开更多
We study a double phase Dirichlet problem with a reaction that has a parametric singular term. Using the Nehari manifold method, we show that for all small values of the parameter, the problem has at least two positiv...We study a double phase Dirichlet problem with a reaction that has a parametric singular term. Using the Nehari manifold method, we show that for all small values of the parameter, the problem has at least two positive, energy minimizing solutions.展开更多
We report an interesting and abnormal electromagnetic phenomenon with regard to a terajet(TJ)that is generated in a reflection mode,which is realized by placing a dielectric scatterer onto a metal reflection plate.We ...We report an interesting and abnormal electromagnetic phenomenon with regard to a terajet(TJ)that is generated in a reflection mode,which is realized by placing a dielectric scatterer onto a metal reflection plate.We show that the introduction of an air hollow into metal reflection plate beneath the scatterer does not induce an expected decrease but an abnormal increase of focal length of the TJ by as much as more than three times.This abnormal phenomenon takes place in case that the air hollow is shallow and there exists a critical hollow depth for a given lateral size of air hollow.Larger than the critical depth,the phenomenon no longer occurs.It is explained from viewpoints of both ray optics in terms of role of relative portion of central waves in TJ formation and electromagnetic field theory with regard to hollow-induced phase singularities.展开更多
基金funded by the National Nature Science Foundation of China(11934009,12174198,and 12227808)the Natural Science Foundation of Jiangsu Province,China(BE2022814)+2 种基金the Universal Technology for Primary and Secondary Schoolsthe National Research Institute for Teaching Materialsthe Qing Lan Project of Jiangsu Province,China。
文摘Acoustic-vortex(AV)tweezers ensure stable particle trapping at a zero-pressure center,while particle assembly between two vortex cores is still prevented by the high-potential barrier.Although a one-dimensional low-pressure attractive path of particle assembly can be constructed by the interference between two independent cylindrical Bessel beams,it remains challenging to create two-dimensional(2D)neighboring vortexes using a source array in practical applications.In this paper,a three-step phase-reversal strategy of 2D particle assembly based on the synchronized evolution of a centrosymmetric array of M off-axis acoustic vortexes(OA-AVs)with a preset radial offset is proposed based on a ring array of planar sources.By introducing initial vortex phase differences of-2π/M and+2π/M to the vortex array,low-pressure patterns of an M-sided regular polygon and M-branched star are formed by connecting the vortex cores and the field center before and after the tangent state of adjacent OA-AVs.Center-oriented particle assembly is finally realized by a central AV constructed by coincident in-phase OA-AVs.The capability of particle manipulation in the lateral and radial directions is demonstrated by low-pressure patterns with acoustic radiation forces pointing to the field center during a synchronized central approach.The field evolution is certified by experimental field measurements for OA-AVs with different vo rtex numbers,initial vortex phase differences,and radial offsets using a ring array of 16 planar sources.The feasibility of particle assembly in two dimensions is also verified by the accurate manipulation of four particles using the low-pressure patterns of a four-sided polygon,a four-branched star,and a central AV in experiments.The three-step strategy paves a new way for 2D particle assembly based on the synchronize d evolution of centrosymmetric OA-AVs using a simplified single-sided source array,exhibiting excellent potential for the precise navigation and manipulation of cells and particles in biomedical applications.
基金supported by the National Key R&D Program of China(2022YFA1404701)Program of Shanghai Academic Research Leader under Grant(22XD1422100)+4 种基金National Natural Science Foundation of China(62075231,12141303,12073018)Shanghai Science and Technology Committee(20JC1414603,23dz2260100)Shanghai Pujiang Program(21PJ1411400)China Postdoctoral Science Foundation(2021M703335)Young Elite Scientists Sponsorship Program by CAST(YESS20220355).
文摘Phase singularities(PSs)in topological darkness-based sensors have received significant attention in optical sensing due to their rapid,ultra-sensitive,and label-free detection capabilities.Here,we present both experimental and theoretical investigations of an ultrasensitive and multiplexed phase-sensitive sensor utilizing dual topological PSs in the visible and near-infrared regions.This sensor uses a simple structure,which consists of an ultra-thin highly absorbing film deposited on a metal substrate.We demonstrate the achievement of dual-polarization darkness points for s-and p-polarizations at different incident angles.Furthermore,we theoretically explain the double topological PSs accompanied by a perfect±π-jump near a zero-reflection point,based on the temporal coupled-mode formalism.To validate its multifunctional capabilities,humidity sensing tests were carried out.The results demonstrate that the sensor has a detection limit reaching the level of 0.12‰.These findings go beyond the scope of conventional interference optical coatings and highlight the potential applications of this technology in gas sensing and biosensing domains.
基金We thank Shiyue Liu from School of Life Sciences in The Chinese University of Hong Kong for helpful discussions.This work is supported under the PROCORE-France/Hong Kong Joint Research Scheme(F-CUHK402/19)the Research Grants Council,Hong Kong Special Administration Region(AoE/P-02/12,14210517,14207419,N_CUHK407/16)the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No.798916.Y.Wang is supported under the Hong Kong PhD Fellowship Scheme.
文摘Detection of small cancer biomarkers with low molecular weight and a low concentration range has always been challenging yet urgent in many clinical applications such as diagnosing early-stage cancer,monitoring treatment and detecting relapse.Here,a highly enhanced plasmonic biosensor that can overcome this challenge is developed using atomically thin two-dimensional phase change nanomaterial.By precisely engineering the configuration with atomically thin materials,the phase singularity has been successfully achieved with a significantly enhanced lateral position shift effect.Based on our knowledge,it is the first experimental demonstration of a lateral position signal change>340μm at a sensing interface from all optical techniques.With this enhanced plasmonic effect,the detection limit has been experimentally demonstrated to be 10^(-15) mol L^(−1) for TNF-α cancer marker,which has been found in various human diseases including inflammatory diseases and different kinds of cancer.The as-reported novel integration of atomically thin Ge_(2)Sb_(2)Te_(5) with plasmonic substrate, which results in a phase singularity and thus a giant lateral position shift, enables the detection of cancer markers with low molecular weight at femtomolar level. These results will definitely hold promising potential in biomedical application and clinical diagnostics.
基金supported by the National Natural Science Foundation of China (Grant No 10574097)the Youth Foundation of University of Electronics Science and Technology of China
文摘By using the generalized Debye diffraction integral, this paper studies the spatial correlation properties and phase singularity annihilation of apertured Gaussian Schell-model （GSM） beams in the focal region. It is shown that the width of the spectral degree of coherence can be larger, less than or equal to the corresponding width of spectral density, which depends not only on the scalar coherence length of the beams, but also on the truncation parameter. With a gradual increase of the truncation parameter, a pair of phase singularities of the spectral degree of coherence in the focal plane approaches each other, resulting in subwavelength structures. Finally, the annihilation of pairs of phase singularities takes place at a certain value of the truncation parameter. With increasing scalar coherence length, the annihilation occurs at the larger truncation parameter. However, the creation process of phase singularities outside the focal plane is not found for GSM beams.
基金supported by the 2023 Beckman Young Investigator Award, from the Arnold and Mabel Beckman FoundationAir Force Office of Scientific Research MURI (Award No. FA9550-22-1-0312)+5 种基金PAIR-UP program sponsored by ASCBfunded in part by The Gordon Moore Foundation, with additional support from the Burroughs Wellcome Funds2022 Scialog: Advancing Bio ImagingKavli Innovation GrantSilicon Valley Community Foundation (Grant No. DAF2023331948)cZi Dynamic imaging via the Chan Zuckerberg Donor Advised Fund (DAF) through the Silicon Valley Community Foundation
文摘Photonic devices that exhibit both sensitivity and robustness have long been sought;yet,these characteristics are thought to be mutually exclusive;through sensitivity,a sensor responds to external stimuli,whereas robustness embodies the inherent ability of a device to withstand weathering by these same stimuli.This challenge stems from the inherent contradiction between robustness and sensitivity in wave dynamics,which require the coexistence of noise-immune sensitive states and modulation-sensitive transitions between these states.We report and experimentally demonstrate a subwavelength phase singularity in a chiral medium that is resilient to fabrication imperfections and disorder while remaining highly responsive to external stimuli.The combination of subwavelength light confinement and its robustness lays the foundation for the development of hitherto unexplored chip-scale photonics devices,enabling a simultaneous development of high-sensitivity and robust devices in both quantum and classical realms.
文摘In this paper, we study the topological structure of the singular points of the third order phase locked loop equations with the character of detected phase being g(?) =(1+k)sin?/1+kcos?.
基金Partially supported by the Natural Science Foundation of Jiangsu Province under Grant No 07KJD140011the National Natural Science Foundation of China under Grant No 10573012Shanghai Municipal Science and Technology Commission(No 04dz05905).
文摘Within the framework of Einstein-Cartan theory,we obtain a general condition leading to singularity and inflation for all Bianchi cosmological models.If the spin energy is smaller than anisotropic energy density(i.e.S^(2)σ^(2)<0),the Universe can not avoid singularity.If S^(2)-σ^(2)>-pv/^(2)(pv is vacuum energy density),the Universe can undergo an inflation phase.Examples of Bianchi type-IX,I and V cosmological models are discussed.
基金supported by National Natural Science Foundation of China and the Cuiying Programme of Lanzhou University
文摘In this paper,knotted objects (RS vortices) in the theory of topological phase singularity in electromagneticfield have been investigated in details.By using the Duan's topological current theory,we rewrite the topological currentform of RS vortices and use this topological current we reveal that the Hopf invariant of RS vortices is just the sum ofthe linking and self-linking numbers of the knotted RS vortices.Furthermore,the conservation of the Hopf invariant inthe splitting,the mergence and the intersection processes of knotted RS vortices is also discussed.
文摘Performed in this work are complex statistical,fractal and singular analyses of phase properties inherent to birefringence networks of protein crystals consisting of optically-thin layers prepared from blood plasma.Within the framework of a statistical approach,the authors have investigated values and ranges for changes of statistical moments of thefirst to the fourth orders that characterize coordinate distributions for phase shifts between orthogonal components of amplitudes inherent to laser radiation transformed by blood plasma with various pathologies.In the framework of the fractal approach,determined are the dimensions of self-similar coordinate phase distributions as well as features of transformation of logarithmic dependences for power spectra of these distributions for various types of hominal mammary gland pathologies.
基金supported by the NNSF of China (12071413, 12111530282)the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie grant agreement No. 823731 CONMECH。
文摘We study a double phase Dirichlet problem with a reaction that has a parametric singular term. Using the Nehari manifold method, we show that for all small values of the parameter, the problem has at least two positive, energy minimizing solutions.
基金Project supported by the National Natural Science Foundation of China(Grant No.61875148)the Key Awards Program of Cultivating Outstanding Innovative Postgraduates in Arts and Sciences of Tianjin University(Grant No.C1-2022002)+3 种基金the Talent Project of Anhui Science and Technology University(Grant No.DQYJ202304)the University-Level Research Project of Tianjin Sino-German University of Applied Sciences(Grant No.zdkt2018-007)China Association for Science and Technology Young Talent Support Project Doctoral Special Programthe National High-level University Scholarship Program for Graduate Students of China Scholarship Council(Grant No.202406250166)。
文摘We report an interesting and abnormal electromagnetic phenomenon with regard to a terajet(TJ)that is generated in a reflection mode,which is realized by placing a dielectric scatterer onto a metal reflection plate.We show that the introduction of an air hollow into metal reflection plate beneath the scatterer does not induce an expected decrease but an abnormal increase of focal length of the TJ by as much as more than three times.This abnormal phenomenon takes place in case that the air hollow is shallow and there exists a critical hollow depth for a given lateral size of air hollow.Larger than the critical depth,the phenomenon no longer occurs.It is explained from viewpoints of both ray optics in terms of role of relative portion of central waves in TJ formation and electromagnetic field theory with regard to hollow-induced phase singularities.
基金supported by National Natural Science Foundation of China(61273197,61503224)Applied Fundamental Research of Qingdao(14-2-4-19-jch)+2 种基金Huangdao District Science and Technology Project(2014-1-33)China Postdoctoral Science Foundation(2015M582115)"Taishan Scholarship"Construction Engineering
