We devote ourselves to finding exact solutions(including perturbed soliton solutions)to a class of semi-linear Schrödinger equations incorporating Kudryashov's self-phase modulation subject to stochastic pert...We devote ourselves to finding exact solutions(including perturbed soliton solutions)to a class of semi-linear Schrödinger equations incorporating Kudryashov's self-phase modulation subject to stochastic perturbations described by multiplicative white noise based on Stratonvich's calculus.By borrowing ideas of the sub-equation method and utilizing a series of changes of variables,we transform the problem of identifying exact solutions into the task of analyzing the dynamical behaviors of an auxiliary planar Hamiltonian dynamical system.We determine the equilibrium points of the introduced auxiliary Hamiltonian system and analyze their Lyapunov stability.Additionally,we conduct a brief bifurcation analysis and a preliminary chaos analysis of the auxiliary Hamiltonian system,assessing their impact on the Lyapunov stability.Based on the insights gained from investigating the dynamics of the introduced auxiliary Hamiltonian system,we discover‘all'of the exact solutions to the stochastic semi-linear Schrödinger equations under consideration.We obtain explicit formulas for exact solutions by examining the phase portrait of the introduced auxiliary Hamiltonian system.The obtained exact solutions include singular and periodic solutions,as well as perturbed bright and dark solitons.For each type of obtained exact solution,we pick one representative to plot its graph,so as to visually display our theoretical results.Compared with other methods for finding exact solutions to deterministic or stochastic partial differential equations,the dynamical system approach has the merit of yielding all possible exact solutions.The stochastic semi-linear Schrödinger equation under consideration can be used to portray the propagation of pulses in an optical fiber,so our study therefore lays the foundation for discovering new solitons optimized for optical communication and contributes to the improvement of optical technologies.展开更多
Self-diffraction appears when the strong laser goes through two-dimensional material suspension,and this spatial self-phase modulation(SPPM)phenomenon can be used to measure nonlinear optical parameters and achieve op...Self-diffraction appears when the strong laser goes through two-dimensional material suspension,and this spatial self-phase modulation(SPPM)phenomenon can be used to measure nonlinear optical parameters and achieve optical switch.At present,the mechanism of SPPM is still ambiguous.The debate mainly focuses on whether the phenomenon is caused by the nonlinear refractive index of the two-dimensional material or the thermal effect of the laser.The lack of theory limits the dimension of the phase modulation to the radius of the diffraction ring and the vertical imbalance.Therefore,it is urgent to establish a unified and universal SSPM theoretical system of two-dimensional material.展开更多
From Maxwell＇s equations and Post＇s formalism, a generalized chiral nonlinear Schr6dinger equation （CNLSE） is obtained for the nonlinear chiral fiber. This equation governs light transmission through a dispersive ...From Maxwell＇s equations and Post＇s formalism, a generalized chiral nonlinear Schr6dinger equation （CNLSE） is obtained for the nonlinear chiral fiber. This equation governs light transmission through a dispersive nonlinear chiral fiber with joint action of chirality in linear and nonlinear ways. The generalized CNLSE shows a modu- lation of chirality to the effect of attenuation and nonlinearity compared with the case for a conventional fiber. Simulations based on the split-step beam propagation method reveal the role of nonlinearity with cooperation to chirality playing in the pulse evolution. By adjusting its strength the role of chirality in forming solitons is demonstrated for a given circularly polarized component. The application of nonlinear optical rotation is also discussed in an all-optical switch.展开更多
The perturbed nonlinear Schrodinger equation(PNLSE)describes the pulse propagation in optical fibers,which results from the interaction of the higher-order dispersion effect,self-steepening(SS)and self-phase modulatio...The perturbed nonlinear Schrodinger equation(PNLSE)describes the pulse propagation in optical fibers,which results from the interaction of the higher-order dispersion effect,self-steepening(SS)and self-phase modulation(SPM).The challenge between these aforementioned phenomena may lead to a dominant one among them.It is worth noticing that the study of modulation instability(MI)leads to the inspection of dominant phenomena(DPh).Indeed,the MI triggers when the coefficient of DPh exceeds a critical value and it may occur that the interaction leads to wave compression.The PNLSE is currently studied in the literature,mainly on finding traveling wave solutions.Here,we are concerned with analyzing the similarity solutions of the PNLSE.The exact solutions are obtained via introducing similarity transformations and by using the extended unified method.The solutions are evaluated numerically and they are shown graphically.It is observed that the intensity of the pulses exhibits self steepening which progresses to shock soliton in ultrashort time(or near t=0).Also,it is found that the real part of the solution exhibits self-phase modulation in time.The study of(MI)determines the critical value for the coefficients of SS,SPM,or high dispersivity to occur.展开更多
We report the numerical and experimental studies of the two-dimensional Brillouin gain spectrum(BGS)distribution deformation induced by the self-phase modulation in the Brillouin optical time domain reflectometry(BOTD...We report the numerical and experimental studies of the two-dimensional Brillouin gain spectrum(BGS)distribution deformation induced by the self-phase modulation in the Brillouin optical time domain reflectometry(BOTDR)with a 20.6 km sensing distance.The BGS distribution deformation is investigated by analyzing the evolution of the point spread function along the fiber in the two-dimensional model of the BOTDR.In the simulation and experimental results,the specific deformation degree of the BGS distribution induced by the self-phase modulation is related to the pump pulse profile,pump pulse peak power,BGS demodulation method,and detected scattered light component.By comprehensively analyzing the evolution of the point spread function induced by the self-phase modulation and using the image deconvolution,a typical BOTDR sensor with a 25 ns pump pulse reaches the 20 cm spatial resolution over the 20.6 km sensing fiber.展开更多
Supercontinuum white laser with large bandwidth and high pulse energy would offer incredible versatility and opportunities for basic science and high technology applications. Here, we report the generation of high-eff...Supercontinuum white laser with large bandwidth and high pulse energy would offer incredible versatility and opportunities for basic science and high technology applications. Here, we report the generation of high-efficiency 2.8-octave-spanning ultraviolet- visible-infrared (UV-Vis-IR) (with 350-2500 nm 25 dB bandwidth) supercontinuum white laser from a single chirped periodically poled lithium niobate (CPPLN) nonlinear crystal via synergic high-harmonic generation (HHG) and self-phase modulation (SPM). The CPPLN exhibits multiple controllable reciprocal-lattice bands to simultaneously support the quasi-phase matching (QPM) for simultaneous broadband 2nd-10th HHG via cascaded three-wave mixing against a broadband fundamental pump laser. Due to the efficient second-order nonlinearity (2nd-NL) up-conversion and significant 3rd-NL SPM effect both in the pump and HHG laser pulses, 350-2500 nm supercontinuum white laser is eventually obtained with 17 μJ per pulse under pump of 45 μJ per pulse mid-infrared femtosecond laser corresponding to an average high conversion efficiency of 37%. Our work opens up a route towards creating UV-Vis-IR all-spectrum white lasers through engineering the synergic action of HHG and SPM effects in nonlinear crystals for applications in ultrafast spectroscopy, single-shot remote sensing, biological imaging, and so on.展开更多
An exceptionally high stimulated Raman scattering[SRS]conversion efficiency to the first Stokes component associated with the secondary[low-frequency and low intensity]vibrational mode v2[~330 cm^[-1]]was observed in ...An exceptionally high stimulated Raman scattering[SRS]conversion efficiency to the first Stokes component associated with the secondary[low-frequency and low intensity]vibrational mode v2[~330 cm^[-1]]was observed in a BaWO4 crystal in a highly transient regime of interaction.The effect takes place in the range of pump pulse energy from~0.1 to~0.5μJ with maximum energy conversion efficiency up to 35%at 0.2μJ.The nature of the observed effects is explained by interference of SRS and self-phase modulation,where the latter is related to a noninstantaneous orientational Kerr nonlinearity in the BaWO4 crystal.展开更多
An ultrashort 10-GHz pulse generation scheme was successfully demonstrated using a bulk material InGaAsP electroabsorption modulator to generate the seed pulse. A self-phase modulation-based reshaper was used after th...An ultrashort 10-GHz pulse generation scheme was successfully demonstrated using a bulk material InGaAsP electroabsorption modulator to generate the seed pulse. A self-phase modulation-based reshaper was used after the adiabatic soliton compression in a comb-like dispersion profiled fiber. Experiments and simulations confirm that the reshaper effectively removes the pulse pedestal and improves the pulse extinction ratio. As a result, the 10-GHz pulse had no pedestal, a high extinction ratio, and a pulse width of only 1.4 ps.展开更多
A new unsaturated wind-chime model is proposed for calculating the formation time of the diffraction rings induced by spatial self-phase modulation(SSPM) in molybdenum disulfide suspension.To optimize the traditional ...A new unsaturated wind-chime model is proposed for calculating the formation time of the diffraction rings induced by spatial self-phase modulation(SSPM) in molybdenum disulfide suspension.To optimize the traditional wind-chime model,the concentration variable of 2 D materials was introduced.The results of the unsaturated wind-chime model match quite well with the SSPM experimental results of molybdenum disulfide.Based on this model,the shortest formation time of diffraction rings and their corresponding concentration and light intensity can be predicted using limited data.Theoretically,by increasing the viscosity coefficient of the solution,the response time of the diffraction ring,to reach the maximum value,can be significantly reduced.It has advanced significance in shortening the response time of photonic diodes.展开更多
While reinforcement learning-based underwater acoustic adaptive modulation shows promise for enabling environment-adaptive communication as supported by extensive simulation-based research,its practical performance re...While reinforcement learning-based underwater acoustic adaptive modulation shows promise for enabling environment-adaptive communication as supported by extensive simulation-based research,its practical performance remains underexplored in field investigations.To evaluate the practical applicability of this emerging technique in adverse shallow sea channels,a field experiment was conducted using three communication modes:orthogonal frequency division multiplexing(OFDM),M-ary frequency-shift keying(MFSK),and direct sequence spread spectrum(DSSS)for reinforcement learning-driven adaptive modulation.Specifically,a Q-learning method is used to select the optimal modulation mode according to the channel quality quantified by signal-to-noise ratio,multipath spread length,and Doppler frequency offset.Experimental results demonstrate that the reinforcement learning-based adaptive modulation scheme outperformed fixed threshold detection in terms of total throughput and average bit error rate,surpassing conventional adaptive modulation strategies.展开更多
A novel method to enhance the bandwidth of a chaotic carrier from a delayed feedback semiconductor laser transmitter is pre- sented using self-phase modulation (SPM) in an optical fiber external round cavity. A physic...A novel method to enhance the bandwidth of a chaotic carrier from a delayed feedback semiconductor laser transmitter is pre- sented using self-phase modulation (SPM) in an optical fiber external round cavity. A physical model of the laser dynamics is established under the condition of optical feedback light with the SPM effect in the fiber path. A formula for frequency detuning of the optical dual-feedback under SPM is theoretically deduced. The results show that the nonlinear phase shift caused by SPM has an impact on the gain and bandwidth enhancement factor of the laser. The second-order nonlinear effect of the fiber enriches the variety of the amplitudes and phases of the laser while the nonlinear phase shift produces a number of new frequencies, which can spread the bandwidth. Numerical results reveal that with the SPM effect, the bandwidth can be enhanced 4 times more than the bandwidth without it, and the relaxation oscillation frequency of the chaotic laser is increased to 2.56 times more than that of the laser without the fiber path. The enhancement of the chaotic bandwidth can be extended by increasing the optical fiber length, the coupling-feedback ratio, the mirror reflectance and the second order nonlinear coefficient affect.展开更多
Diatomic metasurfaces designed for interferometric mechanisms possess significant potential for the multidimensional manipulation of electromagnetic waves,including control over amplitude,phase,frequency,and polarizat...Diatomic metasurfaces designed for interferometric mechanisms possess significant potential for the multidimensional manipulation of electromagnetic waves,including control over amplitude,phase,frequency,and polarization.Geometric phase profiles with spin-selective properties are commonly associated with wavefront modulation,allowing the implementation of conjugate strategies within orthogonal circularly polarized channels.Simultaneous control of these characteristics in a single-layered diatomic metasurface will be an apparent technological extension.Here,spin-selective modulation of terahertz(THz)beams is realized by assembling a pair of meta-atoms with birefringent effects.The distinct modulation functions arise from geometric phase profiles characterized by multiple rotational properties,which introduce independent parametric factors that elucidate their physical significance.By arranging the key parameters,the proposed design strategy can be employed to realize independent amplitude and phase manipulation.A series of THz metasurface samples with specific modulation functions are characterized,experimentally demonstrating the accuracy of on-demand manipulation.This research paves the way for all-silicon meta-optics that may have great potential in imaging,sensing and detection.展开更多
A novel scheme for generating optical chaos is proposed and experimentally demonstrated,which supports to simultaneously produce two low-correlation chaotic signals with wideband spectrum and suppressed time-delay-sig...A novel scheme for generating optical chaos is proposed and experimentally demonstrated,which supports to simultaneously produce two low-correlation chaotic signals with wideband spectrum and suppressed time-delay-signature(TDS).In the proposed scheme,we use the output of an external-cavity semiconductor laser(ECSL)as the driving signal of a phase modulator to modulate the output of a CW laser.Then the phase-modulated continuous-wave(CW)light is split into two parts,one is injected back into the ECSL that outputs one chaotic signal,while the other part is passed through a dispersion module for generating another chaotic signal simultaneously.The experimental results prove that the proposed scheme has three merits.Firstly,it can improve the bandwidth of ECSL-based chaos by several times,and simultaneously generate another wideband flat-spectrum chaotic signal.Secondly,the undesired TDS characteristics of the simultaneously-generated chaotic signals can be efficiently suppressed to an indistinguishable level within a wide parameter range,as such the complexities of the chaotic signals are considerably high.Thirdly,the correlation coefficient between these two simultaneously-generated chaotic signals is smaller than 0.1.The proposed scheme provides an attractive solution for parallel multiple chaos generation,and shows great potential for multiple channel chaos communications and multiple random bit generations.展开更多
All-season thermal management with zero energy consumption and emissions is more crucial to global decarbonization over traditional energy-intensive cooling/heating systems.However,the static single thermal management...All-season thermal management with zero energy consumption and emissions is more crucial to global decarbonization over traditional energy-intensive cooling/heating systems.However,the static single thermal management for cooling or heating fails to self-regulate the temperature in dynamic seasonal temperature condition.Herein,inspired by the dual-temperature regulation function of the fur color changes on the backs and abdomens of penguins,a smart thermal management composite hydrogel(PNA@H-PM Gel)system was subtly created though an"on-demand"dual-layer structure design strategy.The PNA@H-PM Gel system features synchronous solar and thermal radiation modulation as well as tunable phase transition temperatures to meet the variable seasonal thermal requirements and energy-saving demands via self-adaptive radiative cooling and solar heating regulation.Furthermore,this system demonstrates superb modulations of both the solar reflectance(ΔR=0.74)and thermal emissivity(ΔE=0.52)in response to ambient temperature changes,highlighting efficient temperature regulation with average radiative cooling and solar heating effects of 9.6℃in summer and 6.1℃in winter,respectively.Moreover,compared to standard building baselines,the PNA@H-PM Gel presents a more substantial energy-saving cooling/heating potentials for energy-efficient buildings across various regions and climates.This novel solution,inspired by penguins in the real world,will offer a fresh approach for producing intelligent,energy-saving thermal management materials,and serve for temperature regulation under dynamic climate conditions and even throughout all seasons.展开更多
The traditional von Neumann architecture faces inherent limitations due to the separation of memory and computa-tion,leading to high energy consumption,significant latency,and reduced operational efficiency.Neuromorph...The traditional von Neumann architecture faces inherent limitations due to the separation of memory and computa-tion,leading to high energy consumption,significant latency,and reduced operational efficiency.Neuromorphic computing,inspired by the architecture of the human brain,offers a promising alternative by integrating memory and computational func-tions,enabling parallel,high-speed,and energy-efficient information processing.Among various neuromorphic technologies,ion-modulated optoelectronic devices have garnered attention due to their excellent ionic tunability and the availability of multi-dimensional control strategies.This review provides a comprehensive overview of recent progress in ion-modulation optoelec-tronic neuromorphic devices.It elucidates the key mechanisms underlying ionic modulation of light fields,including ion migra-tion dynamics and capture and release of charge through ions.Furthermore,the synthesis of active materials and the proper-ties of these devices are analyzed in detail.The review also highlights the application of ion-modulation optoelectronic devices in artificial vision systems,neuromorphic computing,and other bionic fields.Finally,the existing challenges and future direc-tions for the development of optoelectronic neuromorphic devices are discussed,providing critical insights for advancing this promising field.展开更多
High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,inclu...High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,including high figure of merit(FOM),insulation resistivity(ρ)and depolarization temperature(Td)are indispensable but hard to achieve in lead-free piezoceramics,especially operating at 250°C has not been reported before.Herein,well-balanced performances are achieved in BiFeO3–BaTiO3 ceramics via innovative defect engineering with respect to delicate manganese doping.Due to the synergistic effect of enhancing electrostrictive coefficient by polarization configuration optimization,regulating iron ion oxidation state by high valence manganese ion and stabilizing domain orientation by defect dipole,comprehensive excellent electrical performances(Td=340°C,ρ250°C>10^(7)Ωcm and FOM_(250°C)=4905×10^(–15)m^(2)N^(−1))are realized at the solid solubility limit of manganese ions.The HT-PEHs assembled using the rationally designed piezoceramic can allow for fast charging of commercial electrolytic capacitor at 250°C with high energy conversion efficiency(η=11.43%).These characteristics demonstrate that defect engineering tailored BF-BT can satisfy high-end HT-PEHs requirements,paving a new way in developing selfpowered wireless sensors working in HT environments.展开更多
El Niño-Southern Oscillation(ENSO)is a major driver of climate change in middle and low latitudes and thus strongly influences the terrestrial carbon cycle through land-air interaction.Both the ENSO modulation an...El Niño-Southern Oscillation(ENSO)is a major driver of climate change in middle and low latitudes and thus strongly influences the terrestrial carbon cycle through land-air interaction.Both the ENSO modulation and carbon flux variability are projected to increase in the future,but their connection still needs further investigation.To investigate the impact of future ENSO modulation on carbon flux variability,this study used 10 CMIP6 earth system models to analyze ENSO modulation and carbon flux variability in middle and low latitudes,and their relationship,under different scenarios simulated by CMIP6 models.The results show a high consistency in the simulations,with both ENSO modulation and carbon flux variability showing an increasing trend in the future.The higher the emissions scenario,especially SSP5-8.5 compared to SSP2-4.5,the greater the increase in variability.Carbon flux variability in the middle and low latitudes under SSP2-4.5 increases by 30.9%compared to historical levels during 1951-2000,while under SSP5-8.5 it increases by 58.2%.Further analysis suggests that ENSO influences mid-and low-latitude carbon flux variability primarily through temperature.This occurrence may potentially be attributed to the increased responsiveness of gross primary productivity towards regional temperature fluctuations,combined with the intensified influence of ENSO on land surface temperatures.展开更多
Oxygen evolution reaction(OER)is often regarded as a crucial bottleneck in the field of renewable energy storage and conversion.To further accelerate the sluggish kinetics of OER,a cation and anion modulation strategy...Oxygen evolution reaction(OER)is often regarded as a crucial bottleneck in the field of renewable energy storage and conversion.To further accelerate the sluggish kinetics of OER,a cation and anion modulation strategy is reported here,which has been proven to be effective in preparing highly active electrocatalyst.For example,the cobalt,sulfur,and phosphorus modulated nickel hydroxide(denoted as NiCoPSOH)only needs an overpotential of 232 mV to reach a current density of 20 mA cm^(–2),demonstrating excellent OER performances.The cation and anion modulation facilitates the generation of high-valent Ni species,which would activate the lattice oxygen and switch the OER reaction pathway from conventional adsorbate evolution mechanism to lattice oxygen mechanism(LOM),as evidenced by the results of electrochemical measurements,Raman spectroscopy and differential electrochemical mass spectrometry.The LOM pathway of NiCoPSOH is further verified by the theoretical calculations,including the upshift of O 2p band center,the weakened Ni–O bond and the lowest energy barrier of rate-limiting step.Thus,the anion and cation modulated catalyst NiCoPSOH could effectively accelerate the sluggish OER kinetics.Our work provides a new insight into the cation and anion modulation,and broadens the possibility for the rational design of highly active electrocatalysts.展开更多
Two-terminal(2-T)perovskite(PVK)/CuIn(Ga)Se_(2)(CIGS)tandem solar cells(TSCs)have been considered as an ideal tandem cell because of their best bandgap matching regarding to Shockley–Queisser(S–Q)limits.However,the ...Two-terminal(2-T)perovskite(PVK)/CuIn(Ga)Se_(2)(CIGS)tandem solar cells(TSCs)have been considered as an ideal tandem cell because of their best bandgap matching regarding to Shockley–Queisser(S–Q)limits.However,the nature of the irregular rough morphology of commercial CIGS prevents people from improving tandem device performances.In this paper,D-homoserine lactone hydrochloride is proven to improve coverage of PVK materials on irregular rough CIGS surfaces and also passivate bulk defects by modulating the growth of PVK crystals.In addition,the minority carriers near the PVK/C60 interface and the incompletely passivated trap states caused interface recombination.A surface reconstruction with 2-thiopheneethylammonium iodide and N,N-dimethylformamide assisted passivates the defect sites located at the surface and grain boundaries.Meanwhile,LiF is used to create this field effect,repelling hole carriers away from the PVK and C60 interface and thus reducing recombination.As a result,a 2-T PVK/CIGS tandem yielded a power conversion efficiency of 24.6%(0.16 cm^(2)),one of the highest results for 2-T PVK/CIGS TSCs to our knowledge.This validation underscores the potential of our methodology in achieving superior performance in PVK/CIGS tandem solar cells.展开更多
The subnucleus reticularis dorsalis(SRD),also known as the dorsal reticular nucleus(DRt)or dorsal medullary reticular nucleus(MdD),which resides at the caudal end of the medulla,plays a pivotal role in regulating pain...The subnucleus reticularis dorsalis(SRD),also known as the dorsal reticular nucleus(DRt)or dorsal medullary reticular nucleus(MdD),which resides at the caudal end of the medulla,plays a pivotal role in regulating pain perception.Despite extensive research efforts to unravel its mechanisms,the operational intricacies of SRD remain poorly understood.Advances in experimental methodologies such as brain imaging and chemogenetics have facilitated deeper investigations into the involvement of SRD in various pain disorders.This comprehensive review aims to analyze 36 years(1989–2024)of preclinical research highlighting the critical role of SRD in diffuse noxious inhibitory control(DNIC),also known as conditioned pain modulation(CPM)in humans,and its interconnected neural circuits.Moreover,this review explores the neural circuits related to SRD,including locus coeruleus(LC)-SRD,parabrachial nucleus(PBN)-SRD,rostroventromedial medulla(RVM)-ventrolateral medulla(VLM)-SRD,anterior cingulate cortex(ACC)-SRD,medial medullary reticular formation(mMRF)-SRD,and dorsal striatum(DS)-SRD.Their activation also plays a significant role in analgesia.The pivotal roles of neurotransmitters such asμ-opioid receptor(MOR),noradrenaline,and metabotropic glutamate receptor 7(mGluR7)in modulating SRD responsiveness to pain stimuli are also discussed,as are the influences of SRD on different pain types.This review identified promising avenues for innovative analgesic treatments by shedding light on potential therapeutic strategies targeting SRD.展开更多
基金partially supported by Qing Lan Project of Jiangsu,Suqian Sci.&Tech.Program(Grant Nos.Z2023131 and M202206)the Startup Foundation for Newly Recruited Employees,the Xichu Talents Foundation of Suqian University(Grant No.2022XRC033)the National Natural Science Foundation of China(Grant No.11701050)。
文摘We devote ourselves to finding exact solutions(including perturbed soliton solutions)to a class of semi-linear Schrödinger equations incorporating Kudryashov's self-phase modulation subject to stochastic perturbations described by multiplicative white noise based on Stratonvich's calculus.By borrowing ideas of the sub-equation method and utilizing a series of changes of variables,we transform the problem of identifying exact solutions into the task of analyzing the dynamical behaviors of an auxiliary planar Hamiltonian dynamical system.We determine the equilibrium points of the introduced auxiliary Hamiltonian system and analyze their Lyapunov stability.Additionally,we conduct a brief bifurcation analysis and a preliminary chaos analysis of the auxiliary Hamiltonian system,assessing their impact on the Lyapunov stability.Based on the insights gained from investigating the dynamics of the introduced auxiliary Hamiltonian system,we discover‘all'of the exact solutions to the stochastic semi-linear Schrödinger equations under consideration.We obtain explicit formulas for exact solutions by examining the phase portrait of the introduced auxiliary Hamiltonian system.The obtained exact solutions include singular and periodic solutions,as well as perturbed bright and dark solitons.For each type of obtained exact solution,we pick one representative to plot its graph,so as to visually display our theoretical results.Compared with other methods for finding exact solutions to deterministic or stochastic partial differential equations,the dynamical system approach has the merit of yielding all possible exact solutions.The stochastic semi-linear Schrödinger equation under consideration can be used to portray the propagation of pulses in an optical fiber,so our study therefore lays the foundation for discovering new solitons optimized for optical communication and contributes to the improvement of optical technologies.
基金Project(6187031976)supported by the National Natural Science Foundation of China
文摘Self-diffraction appears when the strong laser goes through two-dimensional material suspension,and this spatial self-phase modulation(SPPM)phenomenon can be used to measure nonlinear optical parameters and achieve optical switch.At present,the mechanism of SPPM is still ambiguous.The debate mainly focuses on whether the phenomenon is caused by the nonlinear refractive index of the two-dimensional material or the thermal effect of the laser.The lack of theory limits the dimension of the phase modulation to the radius of the diffraction ring and the vertical imbalance.Therefore,it is urgent to establish a unified and universal SSPM theoretical system of two-dimensional material.
基金Supported by the National Natural Science Foundation of China under Grant No 60977032the Program for Innovation Research of Science of Harbin Institute of Technology(PIRS-HIT)under Grant No T201407
文摘From Maxwell＇s equations and Post＇s formalism, a generalized chiral nonlinear Schr6dinger equation （CNLSE） is obtained for the nonlinear chiral fiber. This equation governs light transmission through a dispersive nonlinear chiral fiber with joint action of chirality in linear and nonlinear ways. The generalized CNLSE shows a modu- lation of chirality to the effect of attenuation and nonlinearity compared with the case for a conventional fiber. Simulations based on the split-step beam propagation method reveal the role of nonlinearity with cooperation to chirality playing in the pulse evolution. By adjusting its strength the role of chirality in forming solitons is demonstrated for a given circularly polarized component. The application of nonlinear optical rotation is also discussed in an all-optical switch.
文摘The perturbed nonlinear Schrodinger equation(PNLSE)describes the pulse propagation in optical fibers,which results from the interaction of the higher-order dispersion effect,self-steepening(SS)and self-phase modulation(SPM).The challenge between these aforementioned phenomena may lead to a dominant one among them.It is worth noticing that the study of modulation instability(MI)leads to the inspection of dominant phenomena(DPh).Indeed,the MI triggers when the coefficient of DPh exceeds a critical value and it may occur that the interaction leads to wave compression.The PNLSE is currently studied in the literature,mainly on finding traveling wave solutions.Here,we are concerned with analyzing the similarity solutions of the PNLSE.The exact solutions are obtained via introducing similarity transformations and by using the extended unified method.The solutions are evaluated numerically and they are shown graphically.It is observed that the intensity of the pulses exhibits self steepening which progresses to shock soliton in ultrashort time(or near t=0).Also,it is found that the real part of the solution exhibits self-phase modulation in time.The study of(MI)determines the critical value for the coefficients of SS,SPM,or high dispersivity to occur.
基金supported by the National Natural Science Foundation of China(Grant Nos.62105045 and 62205037)the National Science Fund for Distinguished Young Scholars(Grant No.61825501)Chongqing Natural Science Foundation of Innovative Research Groups(Grant No.cstc2020jcyj-cxttX0005).
文摘We report the numerical and experimental studies of the two-dimensional Brillouin gain spectrum(BGS)distribution deformation induced by the self-phase modulation in the Brillouin optical time domain reflectometry(BOTDR)with a 20.6 km sensing distance.The BGS distribution deformation is investigated by analyzing the evolution of the point spread function along the fiber in the two-dimensional model of the BOTDR.In the simulation and experimental results,the specific deformation degree of the BGS distribution induced by the self-phase modulation is related to the pump pulse profile,pump pulse peak power,BGS demodulation method,and detected scattered light component.By comprehensively analyzing the evolution of the point spread function induced by the self-phase modulation and using the image deconvolution,a typical BOTDR sensor with a 25 ns pump pulse reaches the 20 cm spatial resolution over the 20.6 km sensing fiber.
基金National Natural Science Foundation of China(11974119)Science and Technology Project of Guangdong(2020B010190001)+1 种基金Guangdong Innovative and Entrepreneurial Research Team Program(2016ZT06C594)National Key R&D Program of China(2018YFA 0306200).
文摘Supercontinuum white laser with large bandwidth and high pulse energy would offer incredible versatility and opportunities for basic science and high technology applications. Here, we report the generation of high-efficiency 2.8-octave-spanning ultraviolet- visible-infrared (UV-Vis-IR) (with 350-2500 nm 25 dB bandwidth) supercontinuum white laser from a single chirped periodically poled lithium niobate (CPPLN) nonlinear crystal via synergic high-harmonic generation (HHG) and self-phase modulation (SPM). The CPPLN exhibits multiple controllable reciprocal-lattice bands to simultaneously support the quasi-phase matching (QPM) for simultaneous broadband 2nd-10th HHG via cascaded three-wave mixing against a broadband fundamental pump laser. Due to the efficient second-order nonlinearity (2nd-NL) up-conversion and significant 3rd-NL SPM effect both in the pump and HHG laser pulses, 350-2500 nm supercontinuum white laser is eventually obtained with 17 μJ per pulse under pump of 45 μJ per pulse mid-infrared femtosecond laser corresponding to an average high conversion efficiency of 37%. Our work opens up a route towards creating UV-Vis-IR all-spectrum white lasers through engineering the synergic action of HHG and SPM effects in nonlinear crystals for applications in ultrafast spectroscopy, single-shot remote sensing, biological imaging, and so on.
基金funded by the Russian Science Foundation(No.22-79-10068)。
文摘An exceptionally high stimulated Raman scattering[SRS]conversion efficiency to the first Stokes component associated with the secondary[low-frequency and low intensity]vibrational mode v2[~330 cm^[-1]]was observed in a BaWO4 crystal in a highly transient regime of interaction.The effect takes place in the range of pump pulse energy from~0.1 to~0.5μJ with maximum energy conversion efficiency up to 35%at 0.2μJ.The nature of the observed effects is explained by interference of SRS and self-phase modulation,where the latter is related to a noninstantaneous orientational Kerr nonlinearity in the BaWO4 crystal.
基金Supported by the Basic Research Foundation of Tsinghua Na-tional Laboratory for Information Science and Technology (TNList)the National Natural Science Foundation of China (No. 60577033)the Open Fund of the Key Laboratory of Optical Communication and Lightwave Technologies (Beijing University of Posts and Telecommunications), Ministry of Education, China
文摘An ultrashort 10-GHz pulse generation scheme was successfully demonstrated using a bulk material InGaAsP electroabsorption modulator to generate the seed pulse. A self-phase modulation-based reshaper was used after the adiabatic soliton compression in a comb-like dispersion profiled fiber. Experiments and simulations confirm that the reshaper effectively removes the pulse pedestal and improves the pulse extinction ratio. As a result, the 10-GHz pulse had no pedestal, a high extinction ratio, and a pulse width of only 1.4 ps.
基金financially supported by the National Natural Science Foundation of China (Nos. 61875232, 61874141, and 11904239)the China Postdoctoral Science Foundation (No. 2021M690169)
文摘A new unsaturated wind-chime model is proposed for calculating the formation time of the diffraction rings induced by spatial self-phase modulation(SSPM) in molybdenum disulfide suspension.To optimize the traditional wind-chime model,the concentration variable of 2 D materials was introduced.The results of the unsaturated wind-chime model match quite well with the SSPM experimental results of molybdenum disulfide.Based on this model,the shortest formation time of diffraction rings and their corresponding concentration and light intensity can be predicted using limited data.Theoretically,by increasing the viscosity coefficient of the solution,the response time of the diffraction ring,to reach the maximum value,can be significantly reduced.It has advanced significance in shortening the response time of photonic diodes.
基金funding from the National Key Research and Development Program of China(No.2018YFE0110000)the National Natural Science Foundation of China(No.11274259,No.11574258)the Science and Technology Commission Foundation of Shanghai(21DZ1205500)in support of the present research.
文摘While reinforcement learning-based underwater acoustic adaptive modulation shows promise for enabling environment-adaptive communication as supported by extensive simulation-based research,its practical performance remains underexplored in field investigations.To evaluate the practical applicability of this emerging technique in adverse shallow sea channels,a field experiment was conducted using three communication modes:orthogonal frequency division multiplexing(OFDM),M-ary frequency-shift keying(MFSK),and direct sequence spread spectrum(DSSS)for reinforcement learning-driven adaptive modulation.Specifically,a Q-learning method is used to select the optimal modulation mode according to the channel quality quantified by signal-to-noise ratio,multipath spread length,and Doppler frequency offset.Experimental results demonstrate that the reinforcement learning-based adaptive modulation scheme outperformed fixed threshold detection in terms of total throughput and average bit error rate,surpassing conventional adaptive modulation strategies.
基金supported by the Academic Natural Science Basic Item of the Education Department of Jiangsu Province of China (Grant No. 08KJ510019)
文摘A novel method to enhance the bandwidth of a chaotic carrier from a delayed feedback semiconductor laser transmitter is pre- sented using self-phase modulation (SPM) in an optical fiber external round cavity. A physical model of the laser dynamics is established under the condition of optical feedback light with the SPM effect in the fiber path. A formula for frequency detuning of the optical dual-feedback under SPM is theoretically deduced. The results show that the nonlinear phase shift caused by SPM has an impact on the gain and bandwidth enhancement factor of the laser. The second-order nonlinear effect of the fiber enriches the variety of the amplitudes and phases of the laser while the nonlinear phase shift produces a number of new frequencies, which can spread the bandwidth. Numerical results reveal that with the SPM effect, the bandwidth can be enhanced 4 times more than the bandwidth without it, and the relaxation oscillation frequency of the chaotic laser is increased to 2.56 times more than that of the laser without the fiber path. The enhancement of the chaotic bandwidth can be extended by increasing the optical fiber length, the coupling-feedback ratio, the mirror reflectance and the second order nonlinear coefficient affect.
基金supports from National Key Research and Development Program of China(2021YFB2800703)Sichuan Province Science and Technology Support Program(25QNJJ2419)+1 种基金National Natural Science Foundation of China(U22A2008,12404484)Laoshan Laboratory Science and Technology Innovation Project(LSKJ202200801).
文摘Diatomic metasurfaces designed for interferometric mechanisms possess significant potential for the multidimensional manipulation of electromagnetic waves,including control over amplitude,phase,frequency,and polarization.Geometric phase profiles with spin-selective properties are commonly associated with wavefront modulation,allowing the implementation of conjugate strategies within orthogonal circularly polarized channels.Simultaneous control of these characteristics in a single-layered diatomic metasurface will be an apparent technological extension.Here,spin-selective modulation of terahertz(THz)beams is realized by assembling a pair of meta-atoms with birefringent effects.The distinct modulation functions arise from geometric phase profiles characterized by multiple rotational properties,which introduce independent parametric factors that elucidate their physical significance.By arranging the key parameters,the proposed design strategy can be employed to realize independent amplitude and phase manipulation.A series of THz metasurface samples with specific modulation functions are characterized,experimentally demonstrating the accuracy of on-demand manipulation.This research paves the way for all-silicon meta-optics that may have great potential in imaging,sensing and detection.
基金This work was supported by the National Natural Science Foundation of China(Grant no.62171087,61671119)the Sichuan Science and Technology Program(Grant no.2021JDJQ0023)the Fundamental Research Funds for the Central Universities(Grant no.ZYGX2019J003).
文摘A novel scheme for generating optical chaos is proposed and experimentally demonstrated,which supports to simultaneously produce two low-correlation chaotic signals with wideband spectrum and suppressed time-delay-signature(TDS).In the proposed scheme,we use the output of an external-cavity semiconductor laser(ECSL)as the driving signal of a phase modulator to modulate the output of a CW laser.Then the phase-modulated continuous-wave(CW)light is split into two parts,one is injected back into the ECSL that outputs one chaotic signal,while the other part is passed through a dispersion module for generating another chaotic signal simultaneously.The experimental results prove that the proposed scheme has three merits.Firstly,it can improve the bandwidth of ECSL-based chaos by several times,and simultaneously generate another wideband flat-spectrum chaotic signal.Secondly,the undesired TDS characteristics of the simultaneously-generated chaotic signals can be efficiently suppressed to an indistinguishable level within a wide parameter range,as such the complexities of the chaotic signals are considerably high.Thirdly,the correlation coefficient between these two simultaneously-generated chaotic signals is smaller than 0.1.The proposed scheme provides an attractive solution for parallel multiple chaos generation,and shows great potential for multiple channel chaos communications and multiple random bit generations.
基金the funding and generous support of the National Natural Science Foundation of China(52103263,52271249)the Key Project of International Science&Technology Cooperation of Shaanxi Province(2023-GHZD-09)+5 种基金the Key Project of Science Foundation of Education Department of Shaanxi Province(22JY011)the Key Project of Scientific Research and Development of Shaanxi Province(2023GXLH-070)the Qinchuangyuan"Scientist+Engineer"Team of Shaanxi Province(2023KXJ-069)the Key Research and Development Program of Shaanxi(2023-YBGY-488)the Sci-tech Innovation Team of Shaanxi Province(2024RS-CXTD-46)the Key Research and Development Program of Shaanxi Province(2020ZDLGY13-11).
文摘All-season thermal management with zero energy consumption and emissions is more crucial to global decarbonization over traditional energy-intensive cooling/heating systems.However,the static single thermal management for cooling or heating fails to self-regulate the temperature in dynamic seasonal temperature condition.Herein,inspired by the dual-temperature regulation function of the fur color changes on the backs and abdomens of penguins,a smart thermal management composite hydrogel(PNA@H-PM Gel)system was subtly created though an"on-demand"dual-layer structure design strategy.The PNA@H-PM Gel system features synchronous solar and thermal radiation modulation as well as tunable phase transition temperatures to meet the variable seasonal thermal requirements and energy-saving demands via self-adaptive radiative cooling and solar heating regulation.Furthermore,this system demonstrates superb modulations of both the solar reflectance(ΔR=0.74)and thermal emissivity(ΔE=0.52)in response to ambient temperature changes,highlighting efficient temperature regulation with average radiative cooling and solar heating effects of 9.6℃in summer and 6.1℃in winter,respectively.Moreover,compared to standard building baselines,the PNA@H-PM Gel presents a more substantial energy-saving cooling/heating potentials for energy-efficient buildings across various regions and climates.This novel solution,inspired by penguins in the real world,will offer a fresh approach for producing intelligent,energy-saving thermal management materials,and serve for temperature regulation under dynamic climate conditions and even throughout all seasons.
基金supported by National Natural Science Foundation of China(62174164,U23A20568,and U22A2075)National Key Research and Development Project(2021YFA1202600)+2 种基金Talent Plan of Shanghai Branch,Chinese Academy of Sciences(CASSHB-QNPD-2023-022)Ningbo Technology Project(2022A-007-C)Ningbo Key Research and Development Project(2023Z021).
文摘The traditional von Neumann architecture faces inherent limitations due to the separation of memory and computa-tion,leading to high energy consumption,significant latency,and reduced operational efficiency.Neuromorphic computing,inspired by the architecture of the human brain,offers a promising alternative by integrating memory and computational func-tions,enabling parallel,high-speed,and energy-efficient information processing.Among various neuromorphic technologies,ion-modulated optoelectronic devices have garnered attention due to their excellent ionic tunability and the availability of multi-dimensional control strategies.This review provides a comprehensive overview of recent progress in ion-modulation optoelec-tronic neuromorphic devices.It elucidates the key mechanisms underlying ionic modulation of light fields,including ion migra-tion dynamics and capture and release of charge through ions.Furthermore,the synthesis of active materials and the proper-ties of these devices are analyzed in detail.The review also highlights the application of ion-modulation optoelectronic devices in artificial vision systems,neuromorphic computing,and other bionic fields.Finally,the existing challenges and future direc-tions for the development of optoelectronic neuromorphic devices are discussed,providing critical insights for advancing this promising field.
基金supported by the National Natural Science Foundation of China(Grant Nos.52272103 and 52072010)Beijing Natural Science Foundation(Grant Nos.2242029 and JL23004).
文摘High temperature piezoelectric energy harvester(HTPEH)is an important solution to replace chemical battery to achieve independent power supply of HT wireless sensors.However,simultaneously excellent performances,including high figure of merit(FOM),insulation resistivity(ρ)and depolarization temperature(Td)are indispensable but hard to achieve in lead-free piezoceramics,especially operating at 250°C has not been reported before.Herein,well-balanced performances are achieved in BiFeO3–BaTiO3 ceramics via innovative defect engineering with respect to delicate manganese doping.Due to the synergistic effect of enhancing electrostrictive coefficient by polarization configuration optimization,regulating iron ion oxidation state by high valence manganese ion and stabilizing domain orientation by defect dipole,comprehensive excellent electrical performances(Td=340°C,ρ250°C>10^(7)Ωcm and FOM_(250°C)=4905×10^(–15)m^(2)N^(−1))are realized at the solid solubility limit of manganese ions.The HT-PEHs assembled using the rationally designed piezoceramic can allow for fast charging of commercial electrolytic capacitor at 250°C with high energy conversion efficiency(η=11.43%).These characteristics demonstrate that defect engineering tailored BF-BT can satisfy high-end HT-PEHs requirements,paving a new way in developing selfpowered wireless sensors working in HT environments.
基金jointly supported by projects of the National Natural Science Foundation of China [grant numbers 42141017 and 41975112]。
文摘El Niño-Southern Oscillation(ENSO)is a major driver of climate change in middle and low latitudes and thus strongly influences the terrestrial carbon cycle through land-air interaction.Both the ENSO modulation and carbon flux variability are projected to increase in the future,but their connection still needs further investigation.To investigate the impact of future ENSO modulation on carbon flux variability,this study used 10 CMIP6 earth system models to analyze ENSO modulation and carbon flux variability in middle and low latitudes,and their relationship,under different scenarios simulated by CMIP6 models.The results show a high consistency in the simulations,with both ENSO modulation and carbon flux variability showing an increasing trend in the future.The higher the emissions scenario,especially SSP5-8.5 compared to SSP2-4.5,the greater the increase in variability.Carbon flux variability in the middle and low latitudes under SSP2-4.5 increases by 30.9%compared to historical levels during 1951-2000,while under SSP5-8.5 it increases by 58.2%.Further analysis suggests that ENSO influences mid-and low-latitude carbon flux variability primarily through temperature.This occurrence may potentially be attributed to the increased responsiveness of gross primary productivity towards regional temperature fluctuations,combined with the intensified influence of ENSO on land surface temperatures.
文摘Oxygen evolution reaction(OER)is often regarded as a crucial bottleneck in the field of renewable energy storage and conversion.To further accelerate the sluggish kinetics of OER,a cation and anion modulation strategy is reported here,which has been proven to be effective in preparing highly active electrocatalyst.For example,the cobalt,sulfur,and phosphorus modulated nickel hydroxide(denoted as NiCoPSOH)only needs an overpotential of 232 mV to reach a current density of 20 mA cm^(–2),demonstrating excellent OER performances.The cation and anion modulation facilitates the generation of high-valent Ni species,which would activate the lattice oxygen and switch the OER reaction pathway from conventional adsorbate evolution mechanism to lattice oxygen mechanism(LOM),as evidenced by the results of electrochemical measurements,Raman spectroscopy and differential electrochemical mass spectrometry.The LOM pathway of NiCoPSOH is further verified by the theoretical calculations,including the upshift of O 2p band center,the weakened Ni–O bond and the lowest energy barrier of rate-limiting step.Thus,the anion and cation modulated catalyst NiCoPSOH could effectively accelerate the sluggish OER kinetics.Our work provides a new insight into the cation and anion modulation,and broadens the possibility for the rational design of highly active electrocatalysts.
基金supported by“National Natural Science Foundation of China(U21A20171,U20A20245)”“Hubei Provincial Natural Science Foundation of China(2023AFA010)”+1 种基金“Independent Innovation Projects of the Hubei Longzhong Laboratory(2022ZZ-09)”“Social Public Welfare and Basic Research Special Project of Zhongshan(2020B2015).”。
文摘Two-terminal(2-T)perovskite(PVK)/CuIn(Ga)Se_(2)(CIGS)tandem solar cells(TSCs)have been considered as an ideal tandem cell because of their best bandgap matching regarding to Shockley–Queisser(S–Q)limits.However,the nature of the irregular rough morphology of commercial CIGS prevents people from improving tandem device performances.In this paper,D-homoserine lactone hydrochloride is proven to improve coverage of PVK materials on irregular rough CIGS surfaces and also passivate bulk defects by modulating the growth of PVK crystals.In addition,the minority carriers near the PVK/C60 interface and the incompletely passivated trap states caused interface recombination.A surface reconstruction with 2-thiopheneethylammonium iodide and N,N-dimethylformamide assisted passivates the defect sites located at the surface and grain boundaries.Meanwhile,LiF is used to create this field effect,repelling hole carriers away from the PVK and C60 interface and thus reducing recombination.As a result,a 2-T PVK/CIGS tandem yielded a power conversion efficiency of 24.6%(0.16 cm^(2)),one of the highest results for 2-T PVK/CIGS TSCs to our knowledge.This validation underscores the potential of our methodology in achieving superior performance in PVK/CIGS tandem solar cells.
基金funded by the Key Program of the National Natural Science Foundation of China(No.82130122).
文摘The subnucleus reticularis dorsalis(SRD),also known as the dorsal reticular nucleus(DRt)or dorsal medullary reticular nucleus(MdD),which resides at the caudal end of the medulla,plays a pivotal role in regulating pain perception.Despite extensive research efforts to unravel its mechanisms,the operational intricacies of SRD remain poorly understood.Advances in experimental methodologies such as brain imaging and chemogenetics have facilitated deeper investigations into the involvement of SRD in various pain disorders.This comprehensive review aims to analyze 36 years(1989–2024)of preclinical research highlighting the critical role of SRD in diffuse noxious inhibitory control(DNIC),also known as conditioned pain modulation(CPM)in humans,and its interconnected neural circuits.Moreover,this review explores the neural circuits related to SRD,including locus coeruleus(LC)-SRD,parabrachial nucleus(PBN)-SRD,rostroventromedial medulla(RVM)-ventrolateral medulla(VLM)-SRD,anterior cingulate cortex(ACC)-SRD,medial medullary reticular formation(mMRF)-SRD,and dorsal striatum(DS)-SRD.Their activation also plays a significant role in analgesia.The pivotal roles of neurotransmitters such asμ-opioid receptor(MOR),noradrenaline,and metabotropic glutamate receptor 7(mGluR7)in modulating SRD responsiveness to pain stimuli are also discussed,as are the influences of SRD on different pain types.This review identified promising avenues for innovative analgesic treatments by shedding light on potential therapeutic strategies targeting SRD.
