Airy beams and triple-cusp beams are two kinds of accelerating beams. The propagation characteristics and internal topological structures of accelerating Airy beams are well understood because of the developed mathema...Airy beams and triple-cusp beams are two kinds of accelerating beams. The propagation characteristics and internal topological structures of accelerating Airy beams are well understood because of the developed mathematical theory about Airy function. However, limited information is available about the optical characteristics of accelerating triple-cusp beams. In this work, the relationship between Airy beams and triple-cusp beams is examined theoretically and experimentally. Results reveal some important optical characteristics of triple-cusp beams based on the optical characteristics of Airy beams. These findings are expected to provide a foundation for future applications of triple-cusp beams.展开更多
Based on the ABCD matrix formalism,the propagation property of an Airy beam from right-handed material（RHM） to left-handed material（LHM） is investigated.The result shows that when the Airy beam propagates in the L...Based on the ABCD matrix formalism,the propagation property of an Airy beam from right-handed material（RHM） to left-handed material（LHM） is investigated.The result shows that when the Airy beam propagates in the LHM,the intensity self-bending due to its propagation in the RHM can be compensated.In particular,if the propagation distance in the RHM is equal to that in the LHM and the refractive index of the LHM is n L =-1,the transverse intensity distribution of the Airy beam can return to its original state.展开更多
We investigate the dynamics of airy beams propagating in the parity–time(PT) symmetric optical lattices in linear and nonlinear regimes, respectively. For the linear propagation, the position of the channel guided by...We investigate the dynamics of airy beams propagating in the parity–time(PT) symmetric optical lattices in linear and nonlinear regimes, respectively. For the linear propagation, the position of the channel guided by the PT lattice can be shifted by tuning the lattice frequency. The underlying physical mechanism of this phenomenon is also discussed. An interesting phenomenon is found in the nonlinear regime in that the airy beam becomes a tilt channel with several Rayleigh lengths. These findings create new opportunities for optical steering and manipulations.展开更多
We realize broadband acoustic focusing effect by employing two symmetric Airy beams generated from phased arrays,in which the units of the phased arrays consist of different numbers of cavity structures, each of which...We realize broadband acoustic focusing effect by employing two symmetric Airy beams generated from phased arrays,in which the units of the phased arrays consist of different numbers of cavity structures, each of which is composed of a square cavity and two inclined channels in air. The exotic phenomenon arises from the energy overlapping of the two symmetric Airy beams. Besides, we demonstrate the focusing performance with high self-healing property, and discuss the effects of structure parameters on focusing performance, and present the characteristics of the cavity structure with straight channels. Compared with other acoustic lenses, the proposed acoustic lens has advantages of broad bandwidth（about 1.4 kHz）, high self-healing property of focusing performance, and free adjustment of focal length. Our finding should have great potential applications in ultrasound imaging and medical diagnosis.展开更多
The nonparaxial propagation of radially polarized chirped Airy beams(RPCAiBs) in uniaxial crystal orthogonal to the optical axis is analytically studied. The effects of the first and the second order chirp factors, an...The nonparaxial propagation of radially polarized chirped Airy beams(RPCAiBs) in uniaxial crystal orthogonal to the optical axis is analytically studied. The effects of the first and the second order chirp factors, and the ratio of the extraordinary refractive index to the ordinary refractive index on the nonparaxial evolution of RPCAi Bs in different observation planes are investigated in detail. The results show that when one parameter changes, different components behave differently, and even the same component has various behavior in different directions. The initial slope of RPCAi Bs in the x-direction varies more with the first order chirp factor than that in the y-direction. Meanwhile, with the second order chirp factor becoming larger, the depth of the focus of the y-component in the x-direction decreases while that in the y-direction has no difference. In addition, the different ratios of the extraordinary refractive index to the ordinary refractive index change the difference of the depth of the focus between the x-and the y-components.展开更多
Metasurfaces have exhibited considerable capability for generating Airy beams.However,the available plasmonic/dielectric metasurfaces Airy-beam generators have low transmission efficiency and/or poor quality of genera...Metasurfaces have exhibited considerable capability for generating Airy beams.However,the available plasmonic/dielectric metasurfaces Airy-beam generators have low transmission efficiency and/or poor quality of generated beam because they lack the amplitude modulation.Hyperbolic metamaterials(HMMs)have recently provided an alternative strategy for building high-performance meta-devices that are capable of flexibly modulating the phase,amplitude and polarization state of light.Here we reveal that both the propagation phase and the Pancharatnam-Berry phase can contribute to the local transmission phase of circularly polarized electromagnetic waves by using HMMs.This thus provides us with great freedom to design HMM units with different cross-sections to independently control the transmission phase and amplitude.Here,we design circularly polarized Airy-beam generators in the microwave and near-infrared domains,which require binary phase and polynary amplitude,and validate the good performance in the microwave experiment.Our work can facilate the generation of a complicated light field that highly requires independent and complete control of the transmission phase and amplitude under circularly polarized incidence.展开更多
This study proposes an effective method to enhance the accuracy of the Differential Quadrature Method(DQM)for calculating the dynamic characteristics of functionally graded beams by improving the form of discrete node...This study proposes an effective method to enhance the accuracy of the Differential Quadrature Method(DQM)for calculating the dynamic characteristics of functionally graded beams by improving the form of discrete node distribution.Firstly,based on the first-order shear deformation theory,the governing equation of free vibration of a functionally graded beam is transformed into the eigenvalue problem of ordinary differential equations with respect to beam axial displacement,transverse displacement,and cross-sectional rotation angle by considering the effects of shear deformation and rotational inertia of the beam cross-section.Then,ignoring the shear deformation of the beam section and only considering the effect of the rotational inertia of the section,the governing equation of the beam is transformed into the eigenvalue problem of ordinary differential equations with respect to beam transverse displacement.Based on the differential quadrature method theory,the eigenvalue problem of ordinary differential equations is transformed into the eigenvalue problem of standard generalized algebraic equations.Finally,the first several natural frequencies of the beam can be calculated.The feasibility and accuracy of the improved DQM are verified using the finite element method(FEM)and combined with the results of relevant literature.展开更多
In order to investigate the effect of vehicle-bridge coupling on the dynamic characteristics of the bridge,a steel-concrete composite beam suspension bridge is taken as the research object,and a three-dimensional spat...In order to investigate the effect of vehicle-bridge coupling on the dynamic characteristics of the bridge,a steel-concrete composite beam suspension bridge is taken as the research object,and a three-dimensional spatial model of the bridge and a biaxial vehicle model of the vehicle are established,and then a vehicle-bridge coupling vibration system is constructed on the basis of the Nemak-βmethod,and the impact coefficients of each part of the bridge are obtained under different bridge deck unevenness and vehicle speed.The simulation results show that the bridge deck unevenness has the greatest influence on the vibration response of the bridge,and the bridge impact coefficient increases along with the increase in the level of bridge deck unevenness,and the impact coefficient of the main longitudinal girder and the secondary longitudinal girder achieves the maximum value when the level 4 unevenness is 0.328 and 0.314,respectively;when the vehicle speed is increased,the vibration response of the bridge increases and then decreases,and the impact coefficient of the bridge in the middle of the bridge at a speed of 60 km/h achieves the maximum value of 0.192.展开更多
Tunable Airy beams with controllable propagation trajectories have sparked interest in various fields,such as optical manipulation and laser fabrication.Existing research approaches encounter challenges related to ins...Tunable Airy beams with controllable propagation trajectories have sparked interest in various fields,such as optical manipulation and laser fabrication.Existing research approaches encounter challenges related to insufficient compactness and integration feasibility,or they require enhanced tunability to enable real-time dynamic manipulation of the propagation trajectory.In this work,we present a novel method that utilizes a dual metasurface system to surpass these limitations,significantly enhancing the practical potential of the Airy beam.Our approach involves encoding a cubic phase profile and two off-axis Fresnel lens phase profiles across the two metasurfaces.The validity of the proposed strategy has been confirmed through simulation and experimental results.The proposed meta-device addresses the existing limitations and lays the foundation for broadening the applicability of Airy beams across diverse domains,encompassing light-sheet microscopy,laser fabrication,optical tweezers,etc.展开更多
Elliptical airy vortex beams(EAVBs) can spontaneously form easily identifiable topological charge focal spots. They are used for topological charge detection of vortex beams because they have the abruptly autofocusing...Elliptical airy vortex beams(EAVBs) can spontaneously form easily identifiable topological charge focal spots. They are used for topological charge detection of vortex beams because they have the abruptly autofocusing properties of circular airy vortex beams and exhibit unique propagation characteristics. We study the use of the dynamic phase and Pancharatnam–Berry phase principles for generation and modulation of EAVBs by designing complex-amplitude metasurface and phase-only metasurface, at an operating wavelength of 1500 nm. It is found that the focusing pattern of EAVBs in the autofocusing plane splits into |m| + 1 tilted bright spots from the original ring, and the tilted direction is related to the sign of the topological charge number m. Due to the advantages of ultra-thin, ultra-light, and small size of the metasurface, our designed metasurface device has potential applications in improving the channel capacity based on orbital angular momentum communication, information coding, and particle capture compared to spatial light modulation systems that generate EAVBs.展开更多
Propagation characteristics of finite Airy-Gaussian beams through an apertured misaligned first-order ABCD optical system are studied. In this work, the generalized Huygens-Fresnel diffraction integral and the expansi...Propagation characteristics of finite Airy-Gaussian beams through an apertured misaligned first-order ABCD optical system are studied. In this work, the generalized Huygens-Fresnel diffraction integral and the expansion of the hard aperture function into a finite sum of complex Gaussian functions are used. The propagation of Airy-Gaussian beam passing through: an unapertured misaligned optical system, an apertured aligned ABCD optical system and an unapertured aligned ABCD optical system are derived here as particular cases of the main finding. Some numerical simulations are performed in the paper.展开更多
The realization of quantum storage of spatial light field is of great significance to the construction of high-dimensional quantum repeater.In this paper,we experimentally realize the storage and retrieval of circular...The realization of quantum storage of spatial light field is of great significance to the construction of high-dimensional quantum repeater.In this paper,we experimentally realize the storage and retrieval of circular Airy beams(CABs)by using theΛ-type three-level energy system based on the electromagnetically induced transparency in a hot rubidium atomic vapor cell.The weak probe beam field is modulated with phase distribution of CABs by a spatial light modulator.We store the probe circular Airy beam(CAB)into the rubidium atomic vapor cell and retrieve it after the demanded delay.We quantitatively analyze the storage results and give corresponding theoretical explanations.Moreover,we investigate the autofocusing and self-healing effect of the retrieved CAB,which indicates that the properties and beam shape of CAB maintain well after storage.Our work will have potential applications in the storage of high-dimensional quantum information,and is also useful for improving the channel capacities of quantum internet.展开更多
A sandwich beam specimen was fabricated by treating with MR elastomers between two thin aluminum face-plates.Experiment was carried out to investigate the vibration responses of the sandwich beam with respect to the i...A sandwich beam specimen was fabricated by treating with MR elastomers between two thin aluminum face-plates.Experiment was carried out to investigate the vibration responses of the sandwich beam with respect to the intensity of the magnetic field and excitation frequencies.The results show that the sandwich beams with MR elastomers cores have the capabilities of shifting natural frequencies and the vibration amplitudes decrease with the variation of the intensity of external magnetic field.展开更多
Due to their intriguing properties including self-accelera- tion, non-diffraction, and self-healing, Airy beams have attracted a lot of attention and inspired tremendous potential applications in manipulation, biophot...Due to their intriguing properties including self-accelera- tion, non-diffraction, and self-healing, Airy beams have attracted a lot of attention and inspired tremendous potential applications in manipulation, biophotonics, and communication fields such as manipulation of particles,展开更多
In this paper, a governing differential equation of viscoelastic Timoshenko beam including both extension and shear viscosity is developed in the time domain by direct method. To measure the complex moduli and three p...In this paper, a governing differential equation of viscoelastic Timoshenko beam including both extension and shear viscosity is developed in the time domain by direct method. To measure the complex moduli and three parameters of standard linear solid, the forced vibration technique of beam is successfully used for PCL and PMMA specimens. The dynamical characteristics of viscoelastic Timoshenko beams, especially the damping properties, are derived from a considerable number of numerical computations. The analyses show that the viscosity of materials has great influence on dynamical characteristics of structures, especially on damping, and the standard linear solid model is the better one for describing the dynamic behavior of high viscous materials.展开更多
The Fabry–Perot(FP) resonant cavity is widely used in laser and spectroscopic measurements due to its unique interference transfer function(ITF). In the ideal case of parallel incident light, the ITF of the FP resona...The Fabry–Perot(FP) resonant cavity is widely used in laser and spectroscopic measurements due to its unique interference transfer function(ITF). In the ideal case of parallel incident light, the ITF of the FP resonant cavity can be expressed by the Airy function. However, in reality, it is difficult to achieve perfect parallelism with collimated beams. In this article, a theoretical model is established for non-parallel light incidence, which assumes that the non-parallel incident light is a cone-shaped beam, and the cone angle is used to quantify the non-parallelism of the beam. The transmittance function of the FP resonant cavity under non-parallel light incidence is derived. The accuracy of the model is experimentally verified. Based on this model, the effects of divergence angle, tilt angle and FP cavity parameters(reflectivity, cavity length)on the ITF are studied. The reasons for the decrease in peak value, broadening and asymmetry of the interference peak under non-parallel light incidence are explained. It is suggested that a fine balance between the interference peak and the collimation effect of the incident light should be considered in the design and application of FP resonant cavities, especially for tilted applications such as angle-scanned spectroscopy. The research results of this article have certain significance for the design and application of FP resonant cavities.展开更多
We investigate periodic inversion and phase transition of normal and displaced finite-energy Airy beams propagating in nonlocal nonlinear media with the split-step Fourier method. Numerical simulation results show tha...We investigate periodic inversion and phase transition of normal and displaced finite-energy Airy beams propagating in nonlocal nonlinear media with the split-step Fourier method. Numerical simulation results show that parameters such as the degree of nonlocality and amplitude have profound effects on the intensity distribution of the period of an Airy beam. Nonlocal nonlinear media will reduce into a harmonic potential if the nonlocality is strong enough, which results in the beam fluctuating in an approximately cosine mode. The beam profile changes from an Airy profile to a Gaussian one at a critical point, and during propagation the process repeats to form an unusual oscillation. We also briefly discus the two-dimensional case, being equivalent to a product of two one-dimensional cases.展开更多
The propagation dynamics of the Airy Gaussian vortex beams in uniaxial crystals orthogonal to the optical axis has been investigated analytically and numerically. The propagation expression of the beams has been obtai...The propagation dynamics of the Airy Gaussian vortex beams in uniaxial crystals orthogonal to the optical axis has been investigated analytically and numerically. The propagation expression of the beams has been obtained. The propagation features of the Airy Gaussian vortex beams are shown with changes of the distribution factor and the ratio of the extraordinary refractive index to the ordinary refractive index. The correlations between the ratio and the maximum intensity value during the propagation, and its appearing distance have been investigated.展开更多
In a numerical investigation, we demonstrate the evolution of a one-dimensional and two-dimensional finite energy Airy beam in a A-type three-level atomic vapor with linear, cubic, and quintic susceptibilities conside...In a numerical investigation, we demonstrate the evolution of a one-dimensional and two-dimensional finite energy Airy beam in a A-type three-level atomic vapor with linear, cubic, and quintic susceptibilities considered simultaneously with the dressing effect. Quasi-solitons and soliton pairs are observed due to this competition mechanism. We find that the frequency detuning of the pump field and its power greatly affect the formation and evolution of generated solitons. In general, around the two- photon resonance point, and for low intensities of the pump field, it is less difficult to form solitons. This investigation enriches the study of the propagation properties of Airy beams and soliton generation in atomic vapor.展开更多
Using the split-step Fourier transform method, we numerically investigate the generation of breathing solitons in the propagation and interactions of Airy–Gaussian（AiG） beams in a cubic–quintic nonlinear medium in...Using the split-step Fourier transform method, we numerically investigate the generation of breathing solitons in the propagation and interactions of Airy–Gaussian（AiG） beams in a cubic–quintic nonlinear medium in one transverse dimension. We show that the propagation of single AiG beams can generate stable breathing solitons that do not accelerate within a certain initial power range. The propagation direction of these breathing solitons can be controlled by introducing a launch angle to the incident AiG beams. When two AiG beams accelerated in opposite directions interact with each other,different breathing solitons and soliton pairs are observed by adjusting the phase shift, the beam interval, the amplitudes,and the light field distribution of the initial AiG beams.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11274278)the Program for Innovative Research Team,Zhejiang Normal University,China
文摘Airy beams and triple-cusp beams are two kinds of accelerating beams. The propagation characteristics and internal topological structures of accelerating Airy beams are well understood because of the developed mathematical theory about Airy function. However, limited information is available about the optical characteristics of accelerating triple-cusp beams. In this work, the relationship between Airy beams and triple-cusp beams is examined theoretically and experimentally. Results reveal some important optical characteristics of triple-cusp beams based on the optical characteristics of Airy beams. These findings are expected to provide a foundation for future applications of triple-cusp beams.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60977068,61178015 and 11102100)the Youth Foundation of Sanming University,China (Grant No. B201008/Q)
文摘Based on the ABCD matrix formalism,the propagation property of an Airy beam from right-handed material（RHM） to left-handed material（LHM） is investigated.The result shows that when the Airy beam propagates in the LHM,the intensity self-bending due to its propagation in the RHM can be compensated.In particular,if the propagation distance in the RHM is equal to that in the LHM and the refractive index of the LHM is n L =-1,the transverse intensity distribution of the Airy beam can return to its original state.
文摘We investigate the dynamics of airy beams propagating in the parity–time(PT) symmetric optical lattices in linear and nonlinear regimes, respectively. For the linear propagation, the position of the channel guided by the PT lattice can be shifted by tuning the lattice frequency. The underlying physical mechanism of this phenomenon is also discussed. An interesting phenomenon is found in the nonlinear regime in that the airy beam becomes a tilt channel with several Rayleigh lengths. These findings create new opportunities for optical steering and manipulations.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11774137 and 11404147)the Major Program of the National Natural Science Foundation of China(Grant No.51239005)+2 种基金the Natural Science Foundation of Jiangsu Province,China(Grant Nos.BK20140519 and BK20140523)the Jiangsu Qing Lan Project,Chinathe Practice Innovation Training Program Projects for Industrial Center of Jiangsu University,China
文摘We realize broadband acoustic focusing effect by employing two symmetric Airy beams generated from phased arrays,in which the units of the phased arrays consist of different numbers of cavity structures, each of which is composed of a square cavity and two inclined channels in air. The exotic phenomenon arises from the energy overlapping of the two symmetric Airy beams. Besides, we demonstrate the focusing performance with high self-healing property, and discuss the effects of structure parameters on focusing performance, and present the characteristics of the cavity structure with straight channels. Compared with other acoustic lenses, the proposed acoustic lens has advantages of broad bandwidth（about 1.4 kHz）, high self-healing property of focusing performance, and free adjustment of focal length. Our finding should have great potential applications in ultrasound imaging and medical diagnosis.
基金Projected supported by the National Natural Science Foundation of China(Grant Nos.11775083 and 11374108)the Science and Technology Program of Guangzhou Province,China(Grant No.2019050001)the Special Funds for the Cultivation of Guangdong College Students’Scientific and Technological Innovation,China(Grant No.pdjh2020a0149)。
文摘The nonparaxial propagation of radially polarized chirped Airy beams(RPCAiBs) in uniaxial crystal orthogonal to the optical axis is analytically studied. The effects of the first and the second order chirp factors, and the ratio of the extraordinary refractive index to the ordinary refractive index on the nonparaxial evolution of RPCAi Bs in different observation planes are investigated in detail. The results show that when one parameter changes, different components behave differently, and even the same component has various behavior in different directions. The initial slope of RPCAi Bs in the x-direction varies more with the first order chirp factor than that in the y-direction. Meanwhile, with the second order chirp factor becoming larger, the depth of the focus of the y-component in the x-direction decreases while that in the y-direction has no difference. In addition, the different ratios of the extraordinary refractive index to the ordinary refractive index change the difference of the depth of the focus between the x-and the y-components.
基金the National Natural Science Foundation of China(Grant Nos.11474116 and 11674118).
文摘Metasurfaces have exhibited considerable capability for generating Airy beams.However,the available plasmonic/dielectric metasurfaces Airy-beam generators have low transmission efficiency and/or poor quality of generated beam because they lack the amplitude modulation.Hyperbolic metamaterials(HMMs)have recently provided an alternative strategy for building high-performance meta-devices that are capable of flexibly modulating the phase,amplitude and polarization state of light.Here we reveal that both the propagation phase and the Pancharatnam-Berry phase can contribute to the local transmission phase of circularly polarized electromagnetic waves by using HMMs.This thus provides us with great freedom to design HMM units with different cross-sections to independently control the transmission phase and amplitude.Here,we design circularly polarized Airy-beam generators in the microwave and near-infrared domains,which require binary phase and polynary amplitude,and validate the good performance in the microwave experiment.Our work can facilate the generation of a complicated light field that highly requires independent and complete control of the transmission phase and amplitude under circularly polarized incidence.
基金Anhui Provincial Natural Science Foundation(2308085QD124)Anhui Province University Natural Science Research Project(GrantNo.2023AH050918)The University Outstanding Youth Talent Support Program of Anhui Province.
文摘This study proposes an effective method to enhance the accuracy of the Differential Quadrature Method(DQM)for calculating the dynamic characteristics of functionally graded beams by improving the form of discrete node distribution.Firstly,based on the first-order shear deformation theory,the governing equation of free vibration of a functionally graded beam is transformed into the eigenvalue problem of ordinary differential equations with respect to beam axial displacement,transverse displacement,and cross-sectional rotation angle by considering the effects of shear deformation and rotational inertia of the beam cross-section.Then,ignoring the shear deformation of the beam section and only considering the effect of the rotational inertia of the section,the governing equation of the beam is transformed into the eigenvalue problem of ordinary differential equations with respect to beam transverse displacement.Based on the differential quadrature method theory,the eigenvalue problem of ordinary differential equations is transformed into the eigenvalue problem of standard generalized algebraic equations.Finally,the first several natural frequencies of the beam can be calculated.The feasibility and accuracy of the improved DQM are verified using the finite element method(FEM)and combined with the results of relevant literature.
基金National Natural Science Foundation of China(11572001,51478004)2021 Undergraduate Course Ideological and Political Demonstration Course-Theoretical Mechanics(108051360022XN569)2022 Great Innovation Project-Frame Bridge Structural Engineering Research(108051360022XN388)。
文摘In order to investigate the effect of vehicle-bridge coupling on the dynamic characteristics of the bridge,a steel-concrete composite beam suspension bridge is taken as the research object,and a three-dimensional spatial model of the bridge and a biaxial vehicle model of the vehicle are established,and then a vehicle-bridge coupling vibration system is constructed on the basis of the Nemak-βmethod,and the impact coefficients of each part of the bridge are obtained under different bridge deck unevenness and vehicle speed.The simulation results show that the bridge deck unevenness has the greatest influence on the vibration response of the bridge,and the bridge impact coefficient increases along with the increase in the level of bridge deck unevenness,and the impact coefficient of the main longitudinal girder and the secondary longitudinal girder achieves the maximum value when the level 4 unevenness is 0.328 and 0.314,respectively;when the vehicle speed is increased,the vibration response of the bridge increases and then decreases,and the impact coefficient of the bridge in the middle of the bridge at a speed of 60 km/h achieves the maximum value of 0.192.
文摘Tunable Airy beams with controllable propagation trajectories have sparked interest in various fields,such as optical manipulation and laser fabrication.Existing research approaches encounter challenges related to insufficient compactness and integration feasibility,or they require enhanced tunability to enable real-time dynamic manipulation of the propagation trajectory.In this work,we present a novel method that utilizes a dual metasurface system to surpass these limitations,significantly enhancing the practical potential of the Airy beam.Our approach involves encoding a cubic phase profile and two off-axis Fresnel lens phase profiles across the two metasurfaces.The validity of the proposed strategy has been confirmed through simulation and experimental results.The proposed meta-device addresses the existing limitations and lays the foundation for broadening the applicability of Airy beams across diverse domains,encompassing light-sheet microscopy,laser fabrication,optical tweezers,etc.
基金supported by the National Natural Science Foundation of China (Grant No. 61975185)the Natural Science Foundation of Zhejiang Province, China (Grant Nos. LY19F030004 and LY20F050002)。
文摘Elliptical airy vortex beams(EAVBs) can spontaneously form easily identifiable topological charge focal spots. They are used for topological charge detection of vortex beams because they have the abruptly autofocusing properties of circular airy vortex beams and exhibit unique propagation characteristics. We study the use of the dynamic phase and Pancharatnam–Berry phase principles for generation and modulation of EAVBs by designing complex-amplitude metasurface and phase-only metasurface, at an operating wavelength of 1500 nm. It is found that the focusing pattern of EAVBs in the autofocusing plane splits into |m| + 1 tilted bright spots from the original ring, and the tilted direction is related to the sign of the topological charge number m. Due to the advantages of ultra-thin, ultra-light, and small size of the metasurface, our designed metasurface device has potential applications in improving the channel capacity based on orbital angular momentum communication, information coding, and particle capture compared to spatial light modulation systems that generate EAVBs.
文摘Propagation characteristics of finite Airy-Gaussian beams through an apertured misaligned first-order ABCD optical system are studied. In this work, the generalized Huygens-Fresnel diffraction integral and the expansion of the hard aperture function into a finite sum of complex Gaussian functions are used. The propagation of Airy-Gaussian beam passing through: an unapertured misaligned optical system, an apertured aligned ABCD optical system and an unapertured aligned ABCD optical system are derived here as particular cases of the main finding. Some numerical simulations are performed in the paper.
基金Project supported by the Youth Innovation Promotion Association of Chinese Academy of Sciences。
文摘The realization of quantum storage of spatial light field is of great significance to the construction of high-dimensional quantum repeater.In this paper,we experimentally realize the storage and retrieval of circular Airy beams(CABs)by using theΛ-type three-level energy system based on the electromagnetically induced transparency in a hot rubidium atomic vapor cell.The weak probe beam field is modulated with phase distribution of CABs by a spatial light modulator.We store the probe circular Airy beam(CAB)into the rubidium atomic vapor cell and retrieve it after the demanded delay.We quantitatively analyze the storage results and give corresponding theoretical explanations.Moreover,we investigate the autofocusing and self-healing effect of the retrieved CAB,which indicates that the properties and beam shape of CAB maintain well after storage.Our work will have potential applications in the storage of high-dimensional quantum information,and is also useful for improving the channel capacities of quantum internet.
基金Project(10602033) supported by the National Natural Science Foundation of ChinaProject(07B012) supported by Scientific Research Fund of Education Department of Hunan ProvinceProject(VSN-2007-01) supported the Research Fund of State Key Laboratory of Mechanical System and Vibration
文摘A sandwich beam specimen was fabricated by treating with MR elastomers between two thin aluminum face-plates.Experiment was carried out to investigate the vibration responses of the sandwich beam with respect to the intensity of the magnetic field and excitation frequencies.The results show that the sandwich beams with MR elastomers cores have the capabilities of shifting natural frequencies and the vibration amplitudes decrease with the variation of the intensity of external magnetic field.
基金supported by the National Natural Science Foundation of China(Nos.11604058 and 61367004)the Guangxi Key Laboratory for Relativistic Astrophysics-Guangxi Natural Science Creative Team Funding(No.2013GXNSFFA019001)the Guangxi Natural Science Foundation(No.2016GXNSFBA380244)
文摘Due to their intriguing properties including self-accelera- tion, non-diffraction, and self-healing, Airy beams have attracted a lot of attention and inspired tremendous potential applications in manipulation, biophotonics, and communication fields such as manipulation of particles,
文摘In this paper, a governing differential equation of viscoelastic Timoshenko beam including both extension and shear viscosity is developed in the time domain by direct method. To measure the complex moduli and three parameters of standard linear solid, the forced vibration technique of beam is successfully used for PCL and PMMA specimens. The dynamical characteristics of viscoelastic Timoshenko beams, especially the damping properties, are derived from a considerable number of numerical computations. The analyses show that the viscosity of materials has great influence on dynamical characteristics of structures, especially on damping, and the standard linear solid model is the better one for describing the dynamic behavior of high viscous materials.
基金Project supported by the National Natural Science Foundation of China (Grant No.U19A2044)the National Natural Science Foundation of China (Grant No.41975037)the Key Technologies Research and Development Program of Anhui Province (Grant No.202004i07020013)。
文摘The Fabry–Perot(FP) resonant cavity is widely used in laser and spectroscopic measurements due to its unique interference transfer function(ITF). In the ideal case of parallel incident light, the ITF of the FP resonant cavity can be expressed by the Airy function. However, in reality, it is difficult to achieve perfect parallelism with collimated beams. In this article, a theoretical model is established for non-parallel light incidence, which assumes that the non-parallel incident light is a cone-shaped beam, and the cone angle is used to quantify the non-parallelism of the beam. The transmittance function of the FP resonant cavity under non-parallel light incidence is derived. The accuracy of the model is experimentally verified. Based on this model, the effects of divergence angle, tilt angle and FP cavity parameters(reflectivity, cavity length)on the ITF are studied. The reasons for the decrease in peak value, broadening and asymmetry of the interference peak under non-parallel light incidence are explained. It is suggested that a fine balance between the interference peak and the collimation effect of the incident light should be considered in the design and application of FP resonant cavities, especially for tilted applications such as angle-scanned spectroscopy. The research results of this article have certain significance for the design and application of FP resonant cavities.
文摘We investigate periodic inversion and phase transition of normal and displaced finite-energy Airy beams propagating in nonlocal nonlinear media with the split-step Fourier method. Numerical simulation results show that parameters such as the degree of nonlocality and amplitude have profound effects on the intensity distribution of the period of an Airy beam. Nonlocal nonlinear media will reduce into a harmonic potential if the nonlocality is strong enough, which results in the beam fluctuating in an approximately cosine mode. The beam profile changes from an Airy profile to a Gaussian one at a critical point, and during propagation the process repeats to form an unusual oscillation. We also briefly discus the two-dimensional case, being equivalent to a product of two one-dimensional cases.
基金supported by the National Natural Science Foundation of China(Grant Nos.11374108,11374107,10904041,and 11547212)the Foundation of Cultivating Outstanding Young Scholars of Guangdong Province,China+2 种基金the CAS Key Laboratory of Geospace Environment,University of Science and Technology of Chinathe National Training Program of Innovation and Entrepreneurship for Undergraduates(Grant No.2015093)the Science and Technology Projects of Guangdong Province,China(Grant No.2013B031800011)
文摘The propagation dynamics of the Airy Gaussian vortex beams in uniaxial crystals orthogonal to the optical axis has been investigated analytically and numerically. The propagation expression of the beams has been obtained. The propagation features of the Airy Gaussian vortex beams are shown with changes of the distribution factor and the ratio of the extraordinary refractive index to the ordinary refractive index. The correlations between the ratio and the maximum intensity value during the propagation, and its appearing distance have been investigated.
文摘In a numerical investigation, we demonstrate the evolution of a one-dimensional and two-dimensional finite energy Airy beam in a A-type three-level atomic vapor with linear, cubic, and quintic susceptibilities considered simultaneously with the dressing effect. Quasi-solitons and soliton pairs are observed due to this competition mechanism. We find that the frequency detuning of the pump field and its power greatly affect the formation and evolution of generated solitons. In general, around the two- photon resonance point, and for low intensities of the pump field, it is less difficult to form solitons. This investigation enriches the study of the propagation properties of Airy beams and soliton generation in atomic vapor.
基金Project supported by the National Natural Science Foundation of China(Grant No.51602028)the Science and Technology Development Project of Jilin Province,China(Grant No.20160520114JH)+1 种基金the Youth Science Fund of Changchun University of Science and Technology,China(Grant No.XQNJJ-2017-04)the Natural Science Foundation of Tianjin City,China(Grant No.13JCYBJC16400)
文摘Using the split-step Fourier transform method, we numerically investigate the generation of breathing solitons in the propagation and interactions of Airy–Gaussian（AiG） beams in a cubic–quintic nonlinear medium in one transverse dimension. We show that the propagation of single AiG beams can generate stable breathing solitons that do not accelerate within a certain initial power range. The propagation direction of these breathing solitons can be controlled by introducing a launch angle to the incident AiG beams. When two AiG beams accelerated in opposite directions interact with each other,different breathing solitons and soliton pairs are observed by adjusting the phase shift, the beam interval, the amplitudes,and the light field distribution of the initial AiG beams.
