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
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
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
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
The concept of a quadratic vortex beam is proposed, in which phase term of the beam is given by exp（i mθ2）. The phase of the quadratic vortex beam increases with azimuthal angle nonlinearly. This change in phase pr...The concept of a quadratic vortex beam is proposed, in which phase term of the beam is given by exp（i mθ2）. The phase of the quadratic vortex beam increases with azimuthal angle nonlinearly. This change in phase produces several unexpected effects. Unlike the circularly symmetric beam spot of normal vortex beams, the intensity distribution of the quadratic vortex beam is shown to be asymmetric. The phase singularities will shift in the transverse beam plane on propagation.展开更多
The focusing properties of partially coherent vortex wave fields are studied. Expressions are derived for the intensity distribution and the degree of coherence near the geometrical focus. It is found that the size of...The focusing properties of partially coherent vortex wave fields are studied. Expressions are derived for the intensity distribution and the degree of coherence near the geometrical focus. It is found that the size of coherence vortex dark core in the focal region depends on the topological charges and normalized coherence lengths. It is found that the desired vortex dark core near the geometrical focus can be generated by choosing appropriate values of parameters. The degree of coherence possesses a pair of phase singularities regions in the geometrical focus neighbourhood.展开更多
The topological properties of the spatial coherence function are investigated rigorously. The phase singular structures （coherence vortices） of coherence function can be naturally deduced from the topological curren...The topological properties of the spatial coherence function are investigated rigorously. The phase singular structures （coherence vortices） of coherence function can be naturally deduced from the topological current, which is an abstract mathematical object studied previously. We find that coherence vortices are characterized by the Hopf index and Brouwer degree in topology. The coherence flux quantization and the linking of the closed coherence vortices are also studied from the topological properties of the spatial coherence function.展开更多
Optical metrology is a well-established subject,dating back to early interferometry techniques utilizing light's linear momentum through fringes.In recent years,significant interest has arisen in using vortex ligh...Optical metrology is a well-established subject,dating back to early interferometry techniques utilizing light's linear momentum through fringes.In recent years,significant interest has arisen in using vortex light with orbital angular momentum(OAM),where the phase twists around a singular vortex in space or time.This has expanded metrology's boundaries to encompass highly sensitive chiral interactions between light and matter,three-dimensional motion detection via linear and rotational Doppler effects,and modal approaches surpassing the resolution limit for improved profling and quantification.The intricate structure of vortex light,combined with the integration of artifcial intelligence into optical metrology,unlocks new paradigms for expanding measurement frameworks through additional degrees of freedom,offering the potential for more effcient and accurate sensing and metrological advancements.This review aims to provide a comprehensive overview of recent advances and future trends in optical metrology with structured light,specifically focusing on how utilizing vortex beams has revolutionized metrology and remote sensing,transitioning from classical to quantum approaches.展开更多
Singularities are the positions at which a physical quantity becomes not well-behaved or undefined.In the context of optics,singularities can manifest in various forms,including amplitude,phase,and polarization singul...Singularities are the positions at which a physical quantity becomes not well-behaved or undefined.In the context of optics,singularities can manifest in various forms,including amplitude,phase,and polarization singularities.Among these,polarization singularities are typically classified into V-points,C-points,and L-lines.展开更多
Links and knots are exotic topological structures that have garnered significant interest across multiple branches of natural sciences.Coherent links and knots,such as those constructed by phase or polarization singul...Links and knots are exotic topological structures that have garnered significant interest across multiple branches of natural sciences.Coherent links and knots,such as those constructed by phase or polarization singularities of coherent light,have been observed in various three-dimensional optical settings.However,incoherent links and knots—knotted or connected lines of coherence singularities—arise from a fundamentally different concept.They are"hidden"in the statistic properties of a randomly fluctuating field,making their presence often elusive or undetectable.Here,we theoretically construct and experimentally demonstrate such topological entities of incoherent light.By leveraging a state-of-the-art incoherent modal-decomposition scheme,we unveil incoherent topological structures from fluctuating light speckles,including Hopf links and Trefoil knots of coherence singularities that are robust against coherence and intensity fluctuations.Our work is applicable to diverse wave systems where incoherence or practical coherence is prevalent,and may pave the way for design and implementation of statistically-shaped topological structures for various applications such as high-dimensional optical information encoding and optical communications.展开更多
Orbital angular momentum(OAM), as a fundamental parameter of a photon, has attracted great attention in recent years. Although various properties and applications have been developed by modulating the OAM of photons, ...Orbital angular momentum(OAM), as a fundamental parameter of a photon, has attracted great attention in recent years. Although various properties and applications have been developed by modulating the OAM of photons, there is rare research about the non-uniform OAM. We propose and generate a new kind of continuously tunable azimuthally non-uniform OAM for the first time, to the best of our knowledge, which is carried by a hybridly polarized vector optical field with a cylindrically symmetric intensity profile and a complex polarization singularity. We also present the perfect vector optical field carrying non-uniform OAM with a fixed radius independent of topological charges, which can propagate steadily without radial separation, solving the problem of the unsteady propagation due to the broadened OAM spectrum of the non-uniform OAM. This new kind of tunable non-uniform OAM with a cylindrical symmetric intensity profile, complex polarization singularity, and propagation stability enriches the family of OAMs and can be widely used in many regions such as optical manipulation, quantum optics, and optical communications.展开更多
Research aboutsingularities has been driving scientific advancements across mathematics and physics.Comprehending and harnessing the novel properties of singularities in photonics can facilitate the development of int...Research aboutsingularities has been driving scientific advancements across mathematics and physics.Comprehending and harnessing the novel properties of singularities in photonics can facilitate the development of integrated micro-nano devices in diverse platforms.Herein,we provide a comprehensive overview of photonic singularities emerging in structured lightfields and metamaterial structures.We classify them into several representative types:real-space singularities,momentum-space singularities,and parameter-space singularities,with discussions of their intriguing topological and dynamical properties.Moreover,we report on the latest applications of photonic singularities in broad areas,ranging from light routing,lasing,sensing,and optical manipulation to imaging and display.This review connects the singularity phenomena in different photonic systems,bridging the abstract concepts with emerging practical applications.It underscores the significance of photonic singularities in both fundamental science and various on-chip applications.展开更多
This paper proves a theorem on the decay rate of the oscillatory integral operator with a degenerate C^∞ phase function, thus improving a classical theorem of HSrmander. The proof invokes two new methods to resolve t...This paper proves a theorem on the decay rate of the oscillatory integral operator with a degenerate C^∞ phase function, thus improving a classical theorem of HSrmander. The proof invokes two new methods to resolve the singularity of such kind of operators： a delicate method to decompose the operator and balance the L^2 norm estimates; and a method for resolution of singularity of the convolution type. The operator is decomposed into four major pieces instead of infinite dyadic pieces, which reveals that Cotlar＇s Lemma is not essential for the L^2 estimate of the operator. In the end the conclusion is further improved from the degenerate C^∞ phase function to the degenerate C^4 phase function.展开更多
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.
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.
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 the National Natural Science Foundation of China (Grant No.61178015)the Nurturing Program of National Nature Science Foundation of China (Grant No.JB-ZR1126)the Open Research Fund of State Key Laboratory of Transient Optics and Photonics,Chinese Academy of Sciences (Grant No.SKL ST200912)
文摘The concept of a quadratic vortex beam is proposed, in which phase term of the beam is given by exp（i mθ2）. The phase of the quadratic vortex beam increases with azimuthal angle nonlinearly. This change in phase produces several unexpected effects. Unlike the circularly symmetric beam spot of normal vortex beams, the intensity distribution of the quadratic vortex beam is shown to be asymmetric. The phase singularities will shift in the transverse beam plane on propagation.
基金Supported by the National Natural Science Foundation of China under Grant No 60477041, and the Natural Science Foundation of Fujian Province under Grant No A0510018.
文摘The focusing properties of partially coherent vortex wave fields are studied. Expressions are derived for the intensity distribution and the degree of coherence near the geometrical focus. It is found that the size of coherence vortex dark core in the focal region depends on the topological charges and normalized coherence lengths. It is found that the desired vortex dark core near the geometrical focus can be generated by choosing appropriate values of parameters. The degree of coherence possesses a pair of phase singularities regions in the geometrical focus neighbourhood.
基金Support by the National Natural Science Foundation of China, and Cuiying Programme of Lanzhou University. The authors would like to thank Xin-Hui Zhang, Dong-Hui Xu, and Ran Li for helpful discussions.
文摘The topological properties of the spatial coherence function are investigated rigorously. The phase singular structures （coherence vortices） of coherence function can be naturally deduced from the topological current, which is an abstract mathematical object studied previously. We find that coherence vortices are characterized by the Hopf index and Brouwer degree in topology. The coherence flux quantization and the linking of the closed coherence vortices are also studied from the topological properties of the spatial coherence function.
基金support from the 111 Project(B17035)National Natural Science Foundation of China(Grant no.U20B2059,62231021,61621005,62201613)+2 种基金Shanghai Aerospace Science and Technology Innovation support from the 111 Project(B17035)National Natural Science Foundation of China(Grant no.U20B2059,62231021,61621005,62201613)Shanghai Aerospace Science and Technology Innovation Foundation(SAST-2022-069)。
文摘Optical metrology is a well-established subject,dating back to early interferometry techniques utilizing light's linear momentum through fringes.In recent years,significant interest has arisen in using vortex light with orbital angular momentum(OAM),where the phase twists around a singular vortex in space or time.This has expanded metrology's boundaries to encompass highly sensitive chiral interactions between light and matter,three-dimensional motion detection via linear and rotational Doppler effects,and modal approaches surpassing the resolution limit for improved profling and quantification.The intricate structure of vortex light,combined with the integration of artifcial intelligence into optical metrology,unlocks new paradigms for expanding measurement frameworks through additional degrees of freedom,offering the potential for more effcient and accurate sensing and metrological advancements.This review aims to provide a comprehensive overview of recent advances and future trends in optical metrology with structured light,specifically focusing on how utilizing vortex beams has revolutionized metrology and remote sensing,transitioning from classical to quantum approaches.
文摘Singularities are the positions at which a physical quantity becomes not well-behaved or undefined.In the context of optics,singularities can manifest in various forms,including amplitude,phase,and polarization singularities.Among these,polarization singularities are typically classified into V-points,C-points,and L-lines.
基金supported by the National Key Research and Development Program of China(No.2022YFA1404800)National Natural Science Foundation of China(No.12174280,No.12204340,No.12192254,No.92250304,No.12434012,No.W2441005)Priority Academic Program Development of Jiangsu Higher Education Institutions,and Postgraduate Research&Practice Innovation Programof Jiangsu Province(KYCX24_3287).
文摘Links and knots are exotic topological structures that have garnered significant interest across multiple branches of natural sciences.Coherent links and knots,such as those constructed by phase or polarization singularities of coherent light,have been observed in various three-dimensional optical settings.However,incoherent links and knots—knotted or connected lines of coherence singularities—arise from a fundamentally different concept.They are"hidden"in the statistic properties of a randomly fluctuating field,making their presence often elusive or undetectable.Here,we theoretically construct and experimentally demonstrate such topological entities of incoherent light.By leveraging a state-of-the-art incoherent modal-decomposition scheme,we unveil incoherent topological structures from fluctuating light speckles,including Hopf links and Trefoil knots of coherence singularities that are robust against coherence and intensity fluctuations.Our work is applicable to diverse wave systems where incoherence or practical coherence is prevalent,and may pave the way for design and implementation of statistically-shaped topological structures for various applications such as high-dimensional optical information encoding and optical communications.
基金the National Natural Science Foundation of China(Nos.11534006,11804187,11904199,11674184,and 11774183)Natural Science Foundation of Shandong Province(No.ZR2019BF006)+1 种基金Shandong Province Higher Educational Science and Technology Program(No.J18KA229)Collaborative Innovation Center of Extreme Optics.
文摘Orbital angular momentum(OAM), as a fundamental parameter of a photon, has attracted great attention in recent years. Although various properties and applications have been developed by modulating the OAM of photons, there is rare research about the non-uniform OAM. We propose and generate a new kind of continuously tunable azimuthally non-uniform OAM for the first time, to the best of our knowledge, which is carried by a hybridly polarized vector optical field with a cylindrically symmetric intensity profile and a complex polarization singularity. We also present the perfect vector optical field carrying non-uniform OAM with a fixed radius independent of topological charges, which can propagate steadily without radial separation, solving the problem of the unsteady propagation due to the broadened OAM spectrum of the non-uniform OAM. This new kind of tunable non-uniform OAM with a cylindrical symmetric intensity profile, complex polarization singularity, and propagation stability enriches the family of OAMs and can be widely used in many regions such as optical manipulation, quantum optics, and optical communications.
基金supported by the National Program on Key Basic Research Project of China(2022YFA1404300)National Natural Science Foundation of China(No.12325411,62288101,11774162,12322416)+5 种基金The Open Research Fund of the State Key Laboratory of Transient Optics and Photonics,Chinese Academy of Sciences(SKLST202218)the Fundamental Research Funds for the Central Universities(020414380175)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX23_0096)Work done in Hong Kong is supported by National Natural Science Foundation of China(Grant No.62375232)University Grants Committee/Research Grants Council of the Hong Kong Special Administrative Region,China(Project No.AoE/P-502/20,CRF Project:C1015-21E,C5031-22G,GRF Project:CityU15303521,CityU11305223,and Germany/Hong Kong Joint Research Scheme:G-CityU 101/22)City University of Hong Kong(Projects Nos.9380131,9610628,7005867).
文摘Research aboutsingularities has been driving scientific advancements across mathematics and physics.Comprehending and harnessing the novel properties of singularities in photonics can facilitate the development of integrated micro-nano devices in diverse platforms.Herein,we provide a comprehensive overview of photonic singularities emerging in structured lightfields and metamaterial structures.We classify them into several representative types:real-space singularities,momentum-space singularities,and parameter-space singularities,with discussions of their intriguing topological and dynamical properties.Moreover,we report on the latest applications of photonic singularities in broad areas,ranging from light routing,lasing,sensing,and optical manipulation to imaging and display.This review connects the singularity phenomena in different photonic systems,bridging the abstract concepts with emerging practical applications.It underscores the significance of photonic singularities in both fundamental science and various on-chip applications.
基金the State Key Laboratory of Software Development Environmentthe Grant No.SKLSDE-07-004 under the National Basic Research Program of China (the 973 Program Grant No.2005CB321901)
文摘This paper proves a theorem on the decay rate of the oscillatory integral operator with a degenerate C^∞ phase function, thus improving a classical theorem of HSrmander. The proof invokes two new methods to resolve the singularity of such kind of operators： a delicate method to decompose the operator and balance the L^2 norm estimates; and a method for resolution of singularity of the convolution type. The operator is decomposed into four major pieces instead of infinite dyadic pieces, which reveals that Cotlar＇s Lemma is not essential for the L^2 estimate of the operator. In the end the conclusion is further improved from the degenerate C^∞ phase function to the degenerate C^4 phase function.
