This letter introduces the novel concept of Painlevé solitons—waves arising from the interaction between Painlevé waves and solitons in integrable systems.Painlevé solitons can also be viewed as solito...This letter introduces the novel concept of Painlevé solitons—waves arising from the interaction between Painlevé waves and solitons in integrable systems.Painlevé solitons can also be viewed as solitons propagating against a Painlevé wave background,in analogy to the established notion of elliptic solitons,which refers to solitons on an elliptic wave background.By employing a novel symmetry decomposition method aided by nonlocal residual symmetries,we explicitly construct (extended) Painlevé Ⅱ solitons for the Korteweg-de Vries equation and (extended) Painlevé Ⅳ solitons for the Boussinesq equation.展开更多
We employ the Hirota bilinear method to systematically derive nondegenerate bright one-and two-soliton solutions,along with degenerate bright-dark two-and four-soliton solutions for the reverse-time nonlocal nonlinear...We employ the Hirota bilinear method to systematically derive nondegenerate bright one-and two-soliton solutions,along with degenerate bright-dark two-and four-soliton solutions for the reverse-time nonlocal nonlinear Schr¨odinger equation.Beyond the fundamental nondegenerate one-soliton solution,we have identified and characterized nondegenerate breather bound state solitons,with particular emphasis on their evolution dynamics.展开更多
We investigate the alpha helical protein structure characterized by fourth-order interspine coupling,focusing on a three-coupled fourth-order nonlinear Schr??dinger system.We introduce a generalized Darboux transforma...We investigate the alpha helical protein structure characterized by fourth-order interspine coupling,focusing on a three-coupled fourth-order nonlinear Schr??dinger system.We introduce a generalized Darboux transformation,departing from the classical Darboux transformation.Based on this,we construct the two-and three-degenerate soliton solutions and four-degenerate asymptotic soliton solutions.Based on the asymptotic analysis,we find that the amplitudes of interacting solitons are retained upon the interactions.Elastic interactions between two degenerate solitons exhibiting four curve-type asymptotic solitons are depicted.When the lattice parameterβchanges,the velocities of the two degenerate solitons also change.Elastic interaction among three degenerate solitons comprising four curve-type asymptotic solitons and two line-type solitons is presented.Interaction among one soliton and two degenerate solitons with different velocities is shown.Elastic interaction among four degenerate solitons comprising eight curve-type asymptotic solitons is also presented.Interaction among two two-degenerate solitons with two spectral parameters is shown.The relative distance between two asymptotic solitons exhibits logarithmic growth with|t|,where t represents the retarded time.Acceleration of soliton separation decays exponentially with relative distance,and eventually approaches zero.Phase shifts depend on t.展开更多
This study systematically investigates the attractor characteristics of harmonic solitons in a passively modelocked fiber laser.Through comprehensive analysis in both time and frequency domains,we examine the evolutio...This study systematically investigates the attractor characteristics of harmonic solitons in a passively modelocked fiber laser.Through comprehensive analysis in both time and frequency domains,we examine the evolution of pulse width,spectral bandwidth,and energy across different harmonic orders.The results demonstrate typical soliton attractor behaviors,including attractiveness,dissipativity,and self-organization.In the transition regions between harmonic orders,breathing harmonic soliton states are captured using the time-stretched dispersive Fourier transform.By comparing the breathing dynamics with the stable states,the existence and self-organizing nature of soliton attractors are further confirmed.Finally,harmonic soliton attractors are employed as programmable light sources to achieve ternary optical coding.展开更多
We investigate the dynamic behavior of vector soliton train propagating in optical media,modeled by the coherently coupled nonlinear Schrodinger(NLS)equation.It is shown that an increase in phase parameters,induces an...We investigate the dynamic behavior of vector soliton train propagating in optical media,modeled by the coherently coupled nonlinear Schrodinger(NLS)equation.It is shown that an increase in phase parameters,induces an increase in intensity of the periodic soliton train,as well as the number of pulses for each transverse electric(TE)and transverse magnetic(TM)mode.From the perturbation approach,when examining the propagation states for the transverse electric and magnetic(TEM)mode,we found a family of three bound-vector soliton states with a different propagation parameter at the first order,representing the three possible distinct vector optical fields reconfiguration of the initial profiles one of which is the‘replication’.At the second order,we obtain an eigenvalue problem with an optical external field,giving rise to five high intensity periodic vector soliton structures described by elliptic functions.Such vector soliton trains are intended to complement single-pulse solitons for multi-channel communication applications.展开更多
We propose schemes for realizing various forms of bright solitons,bright vortices,and breathing solitons in a non-resonant,incoherently pumped exciton-polariton condensate system by introducing a two-dimensional Moir&...We propose schemes for realizing various forms of bright solitons,bright vortices,and breathing solitons in a non-resonant,incoherently pumped exciton-polariton condensate system by introducing a two-dimensional Moirélattice external potential.The symmetric shape of the soliton,at the center of the potential field is determined by the rotation angle of the twodimensional Moirélattice external potential.Within a specific range of rotation angles,the stability of the soliton is governed by the depth of the second sub-lattice.These two parameters mutually influence and constrain the soliton’s characteristics,and under certain rotation angles and sub-lattice depths,a bright vortex can be formed.At low pumping levels and with carefully chosen peak-to-valley positions in the external potential,the rotation angle becomes the primary factor controlling the distinct forms of breathing bright solitons.Our proposal provides effective schemes for the formation and control of various types of bright solitons and bright vortices in systems employing Moirélattice external potentials.This scheme for realizing polariton Bose-Einstein condensates(BECs)within a Moirélattice external potential also holds promise for advancing research in fields such as superfluidity and superconductivity.展开更多
Recent theoretical verification of self-similar and dissipative pure-quartic solitons(PQSs)emphasized the similarity between PQS lasers and conventional fiber lasers,but the unique equilibrium mechanism hinders the fo...Recent theoretical verification of self-similar and dissipative pure-quartic solitons(PQSs)emphasized the similarity between PQS lasers and conventional fiber lasers,but the unique equilibrium mechanism hinders the formation of PQS molecules in normal fourth-order dispersion(FOD)regimes.In this paper,we investigated the effect of filters on shaping PQSs in normal FOD based on a passively mode-locked fiber laser model.A bandpass filter eliminates the time pedestal of dissipative PQSs,thus realizing a multi-pulsing state.When the filter bandwidth is appropriate,the effective spectral filtering effect can lower the pulse splitting threshold and enable the coherent restoration from chaotic PQSs to PQS molecules.Additionally,changing the central wavelength of the filter can generate PQSs and PQS molecules with asymmetric intensity distributions.These results are important guides for the manipulation of PQSs and the construction of high repetition-frequency fiber lasers.展开更多
Since the discovery of the electrostatic wave emissions such as broadband electrostatic noise(BEN)and electrostatic hiss in space plasmas,both kinetic and nonlinear fluid studies have been employed to study the proper...Since the discovery of the electrostatic wave emissions such as broadband electrostatic noise(BEN)and electrostatic hiss in space plasmas,both kinetic and nonlinear fluid studies have been employed to study the properties and characteristics of the solitons.Here,we use the Sagdeev pseudo-potential method to investigate the existence of the high-frequency supersolitons in a four-component unmagnetised plasma model composed of hot,warm,and cool electrons and cool ions species.All species are treated as adiabatic and are considered as stationary in our soliton analysis.Although the model supports both slow and fast electron-acoustic soliton,only the solutions of a negative-polarity supersoliton solution of the fast electron-acoustic type are discussed in this research study.It is shown that high-frequency supersoliton exists in a very narrower region of parameter space.Furthermore,the lower and upper Mach numbers for the supersolitons are computed and discussed.We have constructed the existence domains of the supersolitons,and the maximum potential amplitudes are computed.Positive potential supersolitons are not found in our numerical analysis.The importance and applications of our numerical findings in space-plasma environments are also discussed.展开更多
We propose a theoretical framework,based on the two-component Gross-Pitaevskii equation(GPE),for the investigation of vortex solitons(VSs)in hybrid atomic-molecular Bose-Einstein condensates under the action of the st...We propose a theoretical framework,based on the two-component Gross-Pitaevskii equation(GPE),for the investigation of vortex solitons(VSs)in hybrid atomic-molecular Bose-Einstein condensates under the action of the stimulated Raman-induced photoassociation and square-optical-lattice potential.Stationary solutions of the coupled GPE system are obtained by means of the imaginary-time integration,while the temporal dynamics are simulated using the fourth-order Runge-Kutta algorithm.The analysis reveals stable rhombus-shaped VS shapes with topological charges m=1 and 2 of the atomic component.The stability domains and spatial structure of these VSs are governed by three key parameters:the parametric-coupling strength(χ),atomicmolecular interaction strength(g_(12)),and the optical-lattice potential depth(V_(0)).By varyingχand g_(12),we demonstrate a structural transition where four-core rhombus-shaped VSs evolve into eight-core square-shaped modes,highlighting the nontrivial nonlinear dynamics of the system.This work establishes a connection between interactions of cold atoms and topologically structured matter waves in hybrid quantum systems.展开更多
The coupled nonlocal nonlinear Schrödinger equations with variable coefficients are researched using the nonstandard Hirota bilinear method.The two-soliton and double-hump one-soliton solutions for the equations ...The coupled nonlocal nonlinear Schrödinger equations with variable coefficients are researched using the nonstandard Hirota bilinear method.The two-soliton and double-hump one-soliton solutions for the equations are first obtained.By assigning different functions to the variable coefficients,we obtain V-shaped,Y-shaped,wave-type,exponential solitons,and so on.Next,we reveal the influence of the real and imaginary parts of the wave numbers on the double-hump structure based on the soliton solutions.Finally,by setting different wave numbers,we can change the distance and transmission direction of the solitons to analyze their dynamic behavior during collisions.This study establishes a theoretical framework for controlling the dynamics of optical fiber in nonlocal nonlinear systems.展开更多
Optical solitons,as self-sustaining waveforms in a nonlinear medium where dispersion and nonlinear effects are balanced,have key applications in ultrafast laser systems and optical communications.Physics-informed neur...Optical solitons,as self-sustaining waveforms in a nonlinear medium where dispersion and nonlinear effects are balanced,have key applications in ultrafast laser systems and optical communications.Physics-informed neural networks(PINN)provide a new way to solve the nonlinear Schrodinger equation describing the soliton evolution by fusing data-driven and physical constraints.However,the grid point sampling strategy of traditional PINN suffers from high computational complexity and unstable gradient flow,which makes it difficult to capture the physical details efficiently.In this paper,we propose a residual-based adaptive multi-distribution(RAMD)sampling method to optimize the PINN training process by dynamically constructing a multi-modal loss distribution.With a 50%reduction in the number of grid points,RAMD significantly reduces the relative error of PINN and,in particular,optimizes the solution error of the(2+1)Ginzburg–Landau equation from 4.55%to 1.98%.RAMD breaks through the lack of physical constraints in the purely data-driven model by the innovative combination of multi-modal distribution modeling and autonomous sampling control for the design of all-optical communication devices.RAMD provides a high-precision numerical simulation tool for the design of all-optical communication devices,optimization of nonlinear laser devices,and other studies.展开更多
In this paper we use Böcklund transformation to construct soliton solutions for a coupled KdV system.This system was first proposed by Wang in 2010.First we generalize the well-known Bäcklund transformation ...In this paper we use Böcklund transformation to construct soliton solutions for a coupled KdV system.This system was first proposed by Wang in 2010.First we generalize the well-known Bäcklund transformation for the KdV equation to such coupled KdV system.Then from a trivial seed solution,we construct soliton solutions.We also give a nonlinear superposition formula,which allows us to generate multi-soliton solutions.展开更多
In this paper,we study and characterize the volume estimates of geodesic balls on Finsler gradient Ricci solitons.We get the upper bounds on the volumes of geodesic balls of all three kinds of Finsler gradient Ricci s...In this paper,we study and characterize the volume estimates of geodesic balls on Finsler gradient Ricci solitons.We get the upper bounds on the volumes of geodesic balls of all three kinds of Finsler gradient Ricci solitons under certain condition about the Laplacian of thedistance function.展开更多
In the last few years,research on advanced ultrafast photonic devices has attracted great interest from laser physicists.As a semiconductor material with excellent nonlinear saturation absorption characteristics,Ga As...In the last few years,research on advanced ultrafast photonic devices has attracted great interest from laser physicists.As a semiconductor material with excellent nonlinear saturation absorption characteristics,Ga As has been used in solidstate and fiber lasers as a mode-locker.However,the pulse widths that have been reported in the searchable published literature are all long and the shortest is tens of picoseconds.Femtosecond pulse widths,desired for a variety of applications,have not yet been reported in Ga As-based pulsed lasers.In this work,we further explore the nonlinear characteristics of Ga As that has been magnetron sputtered onto the surface of a tapered fiber and its application in the generation of femtosecond lasing via effective dispersion optimization and nonlinearity management.With the enhanced interaction between evanescent waves and Ga As nanosheets,mode-locked soliton pulses as short as 830 fs are generated at repetition rates of 4.64 MHz.As far as we know,this is the first time that femtosecond-level pulses have been generated with a Ga As-based saturable absorber.In addition,soliton molecules,including in the dual-pulse state,are also realized under stronger pumping.This work demonstrates that Ga As-based photonic devices have good application prospects in effective polymorphous ultrashort pulsed laser generation.展开更多
The optical soliton characteristics of GaSb-based~2μm wavelength integrated optical chips have broad application prospects in optoelectronic fields such as optical communications,infrared countermeasures,and gas envi...The optical soliton characteristics of GaSb-based~2μm wavelength integrated optical chips have broad application prospects in optoelectronic fields such as optical communications,infrared countermeasures,and gas environment monitoring.In the research of two-section integrated optical chips,more attention is paid to their passive mode-locked characteristics.The ability of its structure to generate stable soliton transmission has not yet been studied,which will limit its further application in high-performance near-mid infrared optoelectronic technology.In this paper,we design and prepare a GaSb-based~2μm wave-length two-section integrated semiconductor laser chip structure,and test and analyze its related properties of soliton,includ-ing power−injection current−voltage(P−I−V),temperature and mode-locked characteristics.Experimental results show that the chip can achieve stable mode-locked operation at nearly~2μm wavelength and present the working characteristics of near opti-cal soliton states and multi-peak optical soliton states.By comparing and analyzing the measured optical pulse sequence curve with the numerical fitting based on the pure fourth order soliton approximation solution,it is confirmed that the two-section integrated optical chip structure can generate stable transmission of multi-peak optical soliton.This provides a research direc-tion for developing near-mid infrared mode-locked integrated optical chips with high-performance property of optical soliton.展开更多
A direct renormalization method without spectrum theory is proposed to compute the perturbation of solitons in nearly integrable systems with multiple small parameters.The evolution equations of these parameters in un...A direct renormalization method without spectrum theory is proposed to compute the perturbation of solitons in nearly integrable systems with multiple small parameters.The evolution equations of these parameters in unperturbed solitons are obtained as the renormalization equations.Compared with routine methods,the advantages of the renormalization method are that the formulation is only based on a clear and simple mathematical theory,namely the Taylor expansion at a general point,the secular terms in perturbation series are eliminated automatically,any priori physical assumption on the form of the solution is avoided,multiple time scales arise naturally from the final naive perturbation expansion,and the Green’s function and corresponding spectrum of linear differential operators are not needed.As applications,the perturbation of solitons for KDV,MKdV and nonlinear Schrodinger equations,are obtained.展开更多
We investigate dark solitons lying on elliptic function background in the defocusing Hirota equation with third-order dispersion and self-steepening terms.By means of the modified squared wavefunction method,we obtain...We investigate dark solitons lying on elliptic function background in the defocusing Hirota equation with third-order dispersion and self-steepening terms.By means of the modified squared wavefunction method,we obtain the Jacobi's elliptic solution of the defocusing Hirota equation,and solve the related linear matrix eigenvalue problem on elliptic function background.The elliptic N-dark soliton solution in terms of theta functions is constructed by the Darboux transformation and limit technique.The asymptotic dynamical behaviors for the elliptic N-dark soliton solution as t→±∞are studied.Through numerical plots of the elliptic one-,two-and three-dark solitons,the amplification effect on the velocity of elliptic dark solitons,and the compression effect on the soliton spatiotemporal distributions produced by the third-order dispersion and self-steepening terms are discussed.展开更多
This study presents a(2+1)-dimensional complex coupled dispersionless system.A Lax pair is proposed,and the Darboux transformation is employed to construct multisoliton solutions.These solutions exhibit a range of wav...This study presents a(2+1)-dimensional complex coupled dispersionless system.A Lax pair is proposed,and the Darboux transformation is employed to construct multisoliton solutions.These solutions exhibit a range of wave phenomena,including bright and dark solitons,S-shaped formations,parabolic profiles,and periodic wave patterns.Additionally,it is shown that the system is equivalent to the sine-Gordon equation and the negative flow of the modified Korteweg-de Vries hierarchy through appropriate transformations.展开更多
Magnetic solitons are nonlinear,local excitations in magnetic systems.In this study,we theoretically and numerically investigate the properties and generation of one-dimensional(1D)topologically trivial magnetic solit...Magnetic solitons are nonlinear,local excitations in magnetic systems.In this study,we theoretically and numerically investigate the properties and generation of one-dimensional(1D)topologically trivial magnetic solitons in ferromagnetic nanowires.An approximate analytical soliton solution described by two free parameters is validated by comparison with the micromagnetic simulation.Across an interface between two media of different anisotropy,the reflection and refraction of a soliton are highly nonlinear,which differ from linear spin waves.A pair of magnetic solitons that propagate in opposite directions can be generated by alternately applying magnetic-field or spin-polarized-current pulses of opposite directions to at least two successive regions.Each soliton corresponds to a soliton solution that can be controlled by the generation process.These magnetic solitons can be used to drive domain wall motion over a distance determined by the soliton magnitude,allowing for discrete manipulation of domain walls compatible with the digital nature of information technology.Our findings pave the way for the application of topologically trivial solitons in spintronics.展开更多
In this work,we demonstrate the generation of high-performance tunable Raman solitons beyond 3μm in a 10 cm,large-core(40μm)fluorotellurite fiber.The pump source is a high-peak-power Raman soliton generated through ...In this work,we demonstrate the generation of high-performance tunable Raman solitons beyond 3μm in a 10 cm,large-core(40μm)fluorotellurite fiber.The pump source is a high-peak-power Raman soliton generated through soliton fission in a silica fiber.By further cascading the 10 cm highly nonlinear fluorotellurite fiber,this Raman soliton undergoes successive high-order soliton fission and soliton self-frequency shift with a tunable range of 2.7–3.3μm.Such an ultra-short-length and ultra-large-core fiber significantly reduces the pulse width of the 3.3μm Raman soliton to 55 fs,doubling the peak power to 2.3 MW compared to previous studies.Furthermore,owing to the seed's high-repetition-frequency feature,the 3.3μm Raman soliton's power exceeds 2 W.These performance metrics represent the highest levels achieved for Raman solitons at wavelengths above 3μm,offering a simple and effective new approach for generating high-peak-power femtosecond pulses in the mid-infrared spectral region.展开更多
基金supported by the National Natural Science Foundations of China (Grant Nos.12235007,12001424,12271324,and 12501333)the Natural Science Basic research program of Shaanxi Province (Grant Nos.2021JZ-21 and 2024JC-YBQN-0069)+3 种基金the China Postdoctoral Science Foundation (Grant Nos.2020M673332 and 2024M751921)the Fundamental Research Funds for the Central Universities (Grant No.GK202304028)the 2023 Shaanxi Province Postdoctoral Research Project (Grant No.2023BSHEDZZ186)Xi’an University,Xi’an Science and Technology Plan Wutongshu Technology Transfer Action Innovation Team(Grant No.25WTZD07)。
文摘This letter introduces the novel concept of Painlevé solitons—waves arising from the interaction between Painlevé waves and solitons in integrable systems.Painlevé solitons can also be viewed as solitons propagating against a Painlevé wave background,in analogy to the established notion of elliptic solitons,which refers to solitons on an elliptic wave background.By employing a novel symmetry decomposition method aided by nonlocal residual symmetries,we explicitly construct (extended) Painlevé Ⅱ solitons for the Korteweg-de Vries equation and (extended) Painlevé Ⅳ solitons for the Boussinesq equation.
基金supported by the National Natural Science Foundation of China(Grant Nos.12261131495 and 12475008)the Scientific Research and Developed Fund of Zhejiang A&F University(Grant No.2021FR0009)。
文摘We employ the Hirota bilinear method to systematically derive nondegenerate bright one-and two-soliton solutions,along with degenerate bright-dark two-and four-soliton solutions for the reverse-time nonlocal nonlinear Schr¨odinger equation.Beyond the fundamental nondegenerate one-soliton solution,we have identified and characterized nondegenerate breather bound state solitons,with particular emphasis on their evolution dynamics.
基金supported by the Natural Science Foundation of Shandong Province(Grant No.ZR2025QC30)。
文摘We investigate the alpha helical protein structure characterized by fourth-order interspine coupling,focusing on a three-coupled fourth-order nonlinear Schr??dinger system.We introduce a generalized Darboux transformation,departing from the classical Darboux transformation.Based on this,we construct the two-and three-degenerate soliton solutions and four-degenerate asymptotic soliton solutions.Based on the asymptotic analysis,we find that the amplitudes of interacting solitons are retained upon the interactions.Elastic interactions between two degenerate solitons exhibiting four curve-type asymptotic solitons are depicted.When the lattice parameterβchanges,the velocities of the two degenerate solitons also change.Elastic interaction among three degenerate solitons comprising four curve-type asymptotic solitons and two line-type solitons is presented.Interaction among one soliton and two degenerate solitons with different velocities is shown.Elastic interaction among four degenerate solitons comprising eight curve-type asymptotic solitons is also presented.Interaction among two two-degenerate solitons with two spectral parameters is shown.The relative distance between two asymptotic solitons exhibits logarithmic growth with|t|,where t represents the retarded time.Acceleration of soliton separation decays exponentially with relative distance,and eventually approaches zero.Phase shifts depend on t.
基金supported by the National Natural Science Foundation of China(Grant No.12475008)the Scientific Research and Developed Fund of Zhejiang A&F University(Grant No.2021FR0009)。
文摘This study systematically investigates the attractor characteristics of harmonic solitons in a passively modelocked fiber laser.Through comprehensive analysis in both time and frequency domains,we examine the evolution of pulse width,spectral bandwidth,and energy across different harmonic orders.The results demonstrate typical soliton attractor behaviors,including attractiveness,dissipativity,and self-organization.In the transition regions between harmonic orders,breathing harmonic soliton states are captured using the time-stretched dispersive Fourier transform.By comparing the breathing dynamics with the stable states,the existence and self-organizing nature of soliton attractors are further confirmed.Finally,harmonic soliton attractors are employed as programmable light sources to achieve ternary optical coding.
文摘We investigate the dynamic behavior of vector soliton train propagating in optical media,modeled by the coherently coupled nonlinear Schrodinger(NLS)equation.It is shown that an increase in phase parameters,induces an increase in intensity of the periodic soliton train,as well as the number of pulses for each transverse electric(TE)and transverse magnetic(TM)mode.From the perturbation approach,when examining the propagation states for the transverse electric and magnetic(TEM)mode,we found a family of three bound-vector soliton states with a different propagation parameter at the first order,representing the three possible distinct vector optical fields reconfiguration of the initial profiles one of which is the‘replication’.At the second order,we obtain an eigenvalue problem with an optical external field,giving rise to five high intensity periodic vector soliton structures described by elliptic functions.Such vector soliton trains are intended to complement single-pulse solitons for multi-channel communication applications.
基金support from the Natural Science Foundation of Zhejiang Province of China (Grant No. LZ22A050002)the National Natural Science Foundation of China (Grant Nos. 12074343 and 11835011)support from the postdoctoral fellowship of Zhejiang Normal University (Grant No. YS304123952)
文摘We propose schemes for realizing various forms of bright solitons,bright vortices,and breathing solitons in a non-resonant,incoherently pumped exciton-polariton condensate system by introducing a two-dimensional Moirélattice external potential.The symmetric shape of the soliton,at the center of the potential field is determined by the rotation angle of the twodimensional Moirélattice external potential.Within a specific range of rotation angles,the stability of the soliton is governed by the depth of the second sub-lattice.These two parameters mutually influence and constrain the soliton’s characteristics,and under certain rotation angles and sub-lattice depths,a bright vortex can be formed.At low pumping levels and with carefully chosen peak-to-valley positions in the external potential,the rotation angle becomes the primary factor controlling the distinct forms of breathing bright solitons.Our proposal provides effective schemes for the formation and control of various types of bright solitons and bright vortices in systems employing Moirélattice external potentials.This scheme for realizing polariton Bose-Einstein condensates(BECs)within a Moirélattice external potential also holds promise for advancing research in fields such as superfluidity and superconductivity.
基金Project supported by the National Natural Science Foundation of China(Grant No.62175116)。
文摘Recent theoretical verification of self-similar and dissipative pure-quartic solitons(PQSs)emphasized the similarity between PQS lasers and conventional fiber lasers,but the unique equilibrium mechanism hinders the formation of PQS molecules in normal fourth-order dispersion(FOD)regimes.In this paper,we investigated the effect of filters on shaping PQSs in normal FOD based on a passively mode-locked fiber laser model.A bandpass filter eliminates the time pedestal of dissipative PQSs,thus realizing a multi-pulsing state.When the filter bandwidth is appropriate,the effective spectral filtering effect can lower the pulse splitting threshold and enable the coherent restoration from chaotic PQSs to PQS molecules.Additionally,changing the central wavelength of the filter can generate PQSs and PQS molecules with asymmetric intensity distributions.These results are important guides for the manipulation of PQSs and the construction of high repetition-frequency fiber lasers.
基金support of the University of Kwa Zulu Natalthe Walter Sisulu University。
文摘Since the discovery of the electrostatic wave emissions such as broadband electrostatic noise(BEN)and electrostatic hiss in space plasmas,both kinetic and nonlinear fluid studies have been employed to study the properties and characteristics of the solitons.Here,we use the Sagdeev pseudo-potential method to investigate the existence of the high-frequency supersolitons in a four-component unmagnetised plasma model composed of hot,warm,and cool electrons and cool ions species.All species are treated as adiabatic and are considered as stationary in our soliton analysis.Although the model supports both slow and fast electron-acoustic soliton,only the solutions of a negative-polarity supersoliton solution of the fast electron-acoustic type are discussed in this research study.It is shown that high-frequency supersoliton exists in a very narrower region of parameter space.Furthermore,the lower and upper Mach numbers for the supersolitons are computed and discussed.We have constructed the existence domains of the supersolitons,and the maximum potential amplitudes are computed.Positive potential supersolitons are not found in our numerical analysis.The importance and applications of our numerical findings in space-plasma environments are also discussed.
基金supported by the National Natural Science Foundation of China(Grant No.62275075)the Natural Science Foundation of Hubei Soliton Research Association(Grant No.2025HBSRA09)+1 种基金joint supported by Hubei Provincial Natural Science Foundation and Xianning of China(Grant Nos.2025AFD401 and 2025AFD405)Israel Science Foundation(Grant No.1695/22).
文摘We propose a theoretical framework,based on the two-component Gross-Pitaevskii equation(GPE),for the investigation of vortex solitons(VSs)in hybrid atomic-molecular Bose-Einstein condensates under the action of the stimulated Raman-induced photoassociation and square-optical-lattice potential.Stationary solutions of the coupled GPE system are obtained by means of the imaginary-time integration,while the temporal dynamics are simulated using the fourth-order Runge-Kutta algorithm.The analysis reveals stable rhombus-shaped VS shapes with topological charges m=1 and 2 of the atomic component.The stability domains and spatial structure of these VSs are governed by three key parameters:the parametric-coupling strength(χ),atomicmolecular interaction strength(g_(12)),and the optical-lattice potential depth(V_(0)).By varyingχand g_(12),we demonstrate a structural transition where four-core rhombus-shaped VSs evolve into eight-core square-shaped modes,highlighting the nontrivial nonlinear dynamics of the system.This work establishes a connection between interactions of cold atoms and topologically structured matter waves in hybrid quantum systems.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1604200)the National Natural Science Foundation of China(Grant No.12261131495)Institute of Systems Science,Beijing Wuzi University(Grant No.BWUISS21).
文摘The coupled nonlocal nonlinear Schrödinger equations with variable coefficients are researched using the nonstandard Hirota bilinear method.The two-soliton and double-hump one-soliton solutions for the equations are first obtained.By assigning different functions to the variable coefficients,we obtain V-shaped,Y-shaped,wave-type,exponential solitons,and so on.Next,we reveal the influence of the real and imaginary parts of the wave numbers on the double-hump structure based on the soliton solutions.Finally,by setting different wave numbers,we can change the distance and transmission direction of the solitons to analyze their dynamic behavior during collisions.This study establishes a theoretical framework for controlling the dynamics of optical fiber in nonlocal nonlinear systems.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1604200)National Natural Science Foundation of China(Grant No.12261131495)+1 种基金Beijing Municipal Science and Technology Commission,Adminitrative Commission of Zhongguancun Science Park(Grant No.Z231100006623006)Institute of Systems Science,Beijing Wuzi University(Grant No.BWUISS21)。
文摘Optical solitons,as self-sustaining waveforms in a nonlinear medium where dispersion and nonlinear effects are balanced,have key applications in ultrafast laser systems and optical communications.Physics-informed neural networks(PINN)provide a new way to solve the nonlinear Schrodinger equation describing the soliton evolution by fusing data-driven and physical constraints.However,the grid point sampling strategy of traditional PINN suffers from high computational complexity and unstable gradient flow,which makes it difficult to capture the physical details efficiently.In this paper,we propose a residual-based adaptive multi-distribution(RAMD)sampling method to optimize the PINN training process by dynamically constructing a multi-modal loss distribution.With a 50%reduction in the number of grid points,RAMD significantly reduces the relative error of PINN and,in particular,optimizes the solution error of the(2+1)Ginzburg–Landau equation from 4.55%to 1.98%.RAMD breaks through the lack of physical constraints in the purely data-driven model by the innovative combination of multi-modal distribution modeling and autonomous sampling control for the design of all-optical communication devices.RAMD provides a high-precision numerical simulation tool for the design of all-optical communication devices,optimization of nonlinear laser devices,and other studies.
基金Supported by the Jiangsu Higher School Undergraduate Innovation and Entrepreneurship Training Program(202311117078Y)。
文摘In this paper we use Böcklund transformation to construct soliton solutions for a coupled KdV system.This system was first proposed by Wang in 2010.First we generalize the well-known Bäcklund transformation for the KdV equation to such coupled KdV system.Then from a trivial seed solution,we construct soliton solutions.We also give a nonlinear superposition formula,which allows us to generate multi-soliton solutions.
基金Supported by NSFC(Nos.12371051,12141101,11871126)。
文摘In this paper,we study and characterize the volume estimates of geodesic balls on Finsler gradient Ricci solitons.We get the upper bounds on the volumes of geodesic balls of all three kinds of Finsler gradient Ricci solitons under certain condition about the Laplacian of thedistance function.
基金Project supported by the National Natural Science Foundation of China(Grant No.12164030)Young Science and Technology Talents of Inner Mongolia,China(Grant No.NJYT22101)+1 种基金the Central Government Guides Local Science,the Technology Development Fund Projects(Grant No.2023ZY0005)the Science and Technology Plan Projects of Inner Mongolia Autonomous Region of China(Grant No.2023KYPT0012)。
文摘In the last few years,research on advanced ultrafast photonic devices has attracted great interest from laser physicists.As a semiconductor material with excellent nonlinear saturation absorption characteristics,Ga As has been used in solidstate and fiber lasers as a mode-locker.However,the pulse widths that have been reported in the searchable published literature are all long and the shortest is tens of picoseconds.Femtosecond pulse widths,desired for a variety of applications,have not yet been reported in Ga As-based pulsed lasers.In this work,we further explore the nonlinear characteristics of Ga As that has been magnetron sputtered onto the surface of a tapered fiber and its application in the generation of femtosecond lasing via effective dispersion optimization and nonlinearity management.With the enhanced interaction between evanescent waves and Ga As nanosheets,mode-locked soliton pulses as short as 830 fs are generated at repetition rates of 4.64 MHz.As far as we know,this is the first time that femtosecond-level pulses have been generated with a Ga As-based saturable absorber.In addition,soliton molecules,including in the dual-pulse state,are also realized under stronger pumping.This work demonstrates that Ga As-based photonic devices have good application prospects in effective polymorphous ultrashort pulsed laser generation.
基金the National Natural Science Foundation of China(Grant Nos.62274048,62464006,62174046)the Ministry of Education,Singapore(Grant No.MOE-T2EP50121-0005)+1 种基金Hainan Province Science and Technology Special Fund(Grant No.ZDYF2025GXJS007)National Key R&D Program of China(Grant No.2023YFF0722400).
文摘The optical soliton characteristics of GaSb-based~2μm wavelength integrated optical chips have broad application prospects in optoelectronic fields such as optical communications,infrared countermeasures,and gas environment monitoring.In the research of two-section integrated optical chips,more attention is paid to their passive mode-locked characteristics.The ability of its structure to generate stable soliton transmission has not yet been studied,which will limit its further application in high-performance near-mid infrared optoelectronic technology.In this paper,we design and prepare a GaSb-based~2μm wave-length two-section integrated semiconductor laser chip structure,and test and analyze its related properties of soliton,includ-ing power−injection current−voltage(P−I−V),temperature and mode-locked characteristics.Experimental results show that the chip can achieve stable mode-locked operation at nearly~2μm wavelength and present the working characteristics of near opti-cal soliton states and multi-peak optical soliton states.By comparing and analyzing the measured optical pulse sequence curve with the numerical fitting based on the pure fourth order soliton approximation solution,it is confirmed that the two-section integrated optical chip structure can generate stable transmission of multi-peak optical soliton.This provides a research direc-tion for developing near-mid infrared mode-locked integrated optical chips with high-performance property of optical soliton.
基金supported by the Special Program for Ability Promotion of the Basic and Scientific Research(Grant No.2023JCYJ-01).
文摘A direct renormalization method without spectrum theory is proposed to compute the perturbation of solitons in nearly integrable systems with multiple small parameters.The evolution equations of these parameters in unperturbed solitons are obtained as the renormalization equations.Compared with routine methods,the advantages of the renormalization method are that the formulation is only based on a clear and simple mathematical theory,namely the Taylor expansion at a general point,the secular terms in perturbation series are eliminated automatically,any priori physical assumption on the form of the solution is avoided,multiple time scales arise naturally from the final naive perturbation expansion,and the Green’s function and corresponding spectrum of linear differential operators are not needed.As applications,the perturbation of solitons for KDV,MKdV and nonlinear Schrodinger equations,are obtained.
基金supported by the National Natural Science Foundation of China(Grant No.12326304,12326305,12071304)the Shenzhen Natural Science Fund(the Stable Support Plan Program)(Grant No.20220809163103001)+2 种基金the Natural Science Foundation of Henan Province(Grant No.232300420119)the Excellent Science and Technology Innovation Talent Support Program of ZUT(Grant No.K2023YXRC06)Funding for the Enhancement Program of Advantageous Discipline Strength of ZUT(2022)。
文摘We investigate dark solitons lying on elliptic function background in the defocusing Hirota equation with third-order dispersion and self-steepening terms.By means of the modified squared wavefunction method,we obtain the Jacobi's elliptic solution of the defocusing Hirota equation,and solve the related linear matrix eigenvalue problem on elliptic function background.The elliptic N-dark soliton solution in terms of theta functions is constructed by the Darboux transformation and limit technique.The asymptotic dynamical behaviors for the elliptic N-dark soliton solution as t→±∞are studied.Through numerical plots of the elliptic one-,two-and three-dark solitons,the amplification effect on the velocity of elliptic dark solitons,and the compression effect on the soliton spatiotemporal distributions produced by the third-order dispersion and self-steepening terms are discussed.
文摘This study presents a(2+1)-dimensional complex coupled dispersionless system.A Lax pair is proposed,and the Darboux transformation is employed to construct multisoliton solutions.These solutions exhibit a range of wave phenomena,including bright and dark solitons,S-shaped formations,parabolic profiles,and periodic wave patterns.Additionally,it is shown that the system is equivalent to the sine-Gordon equation and the negative flow of the modified Korteweg-de Vries hierarchy through appropriate transformations.
基金supported by the National Natural Science Foundation of China(Grants Nos.11804045 and 12174093)the Natural Science Foundation of Hunan Province of China(Grant No.2025JJ60001)the Fundamental Research Funds for the Central Universities。
文摘Magnetic solitons are nonlinear,local excitations in magnetic systems.In this study,we theoretically and numerically investigate the properties and generation of one-dimensional(1D)topologically trivial magnetic solitons in ferromagnetic nanowires.An approximate analytical soliton solution described by two free parameters is validated by comparison with the micromagnetic simulation.Across an interface between two media of different anisotropy,the reflection and refraction of a soliton are highly nonlinear,which differ from linear spin waves.A pair of magnetic solitons that propagate in opposite directions can be generated by alternately applying magnetic-field or spin-polarized-current pulses of opposite directions to at least two successive regions.Each soliton corresponds to a soliton solution that can be controlled by the generation process.These magnetic solitons can be used to drive domain wall motion over a distance determined by the soliton magnitude,allowing for discrete manipulation of domain walls compatible with the digital nature of information technology.Our findings pave the way for the application of topologically trivial solitons in spintronics.
基金supported by the National Natural Science Foundation of China(Grant Nos.62005004 and 61675009)the Natural Science Foundation of Beijing Municipality(Grant Nos.4204091 and KZ201910005006)the China Postdoctoral Science Foundation(Grant No.212423)。
文摘In this work,we demonstrate the generation of high-performance tunable Raman solitons beyond 3μm in a 10 cm,large-core(40μm)fluorotellurite fiber.The pump source is a high-peak-power Raman soliton generated through soliton fission in a silica fiber.By further cascading the 10 cm highly nonlinear fluorotellurite fiber,this Raman soliton undergoes successive high-order soliton fission and soliton self-frequency shift with a tunable range of 2.7–3.3μm.Such an ultra-short-length and ultra-large-core fiber significantly reduces the pulse width of the 3.3μm Raman soliton to 55 fs,doubling the peak power to 2.3 MW compared to previous studies.Furthermore,owing to the seed's high-repetition-frequency feature,the 3.3μm Raman soliton's power exceeds 2 W.These performance metrics represent the highest levels achieved for Raman solitons at wavelengths above 3μm,offering a simple and effective new approach for generating high-peak-power femtosecond pulses in the mid-infrared spectral region.
