185 results match your criteria multiple solitons

Propagation of the pure-cubic optical solitons and stability analysis in the absence of chromatic dispersion.

Opt Quantum Electron 2021 14;53(9):490. Epub 2021 Aug 14.

Henan Academy of Big Data/School of Mathematics and Statistics, Zhengzhou University, Zhengzhou, 450001 China.

The main concentration of this article is to extract pure-cubic optical solitons in nonlinear optical fiber modeled by nonlinear Schrödinger equation (NLSE). The governing model is discussed the with the effect of third-order dispersion, Kerr law of nonlinearity and without chromatic dispersion. We extract the solutions in different forms like, Jacobi's elliptic, hyperbolic, periodic, exponential function solutions including a class of solitary wave solutions such that bright, dark, singular, kink-shape, multiple-optical soliton, and mixed complex soliton solutions. Read More

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Tubular laser solitons.

Opt Lett 2021 Aug;46(16):4076-4079

We analyze, to the best of our knowledge, a new type of topological optical solitons in lasers with fast saturable absorption, which is intermediate between 2D and 3D ones. Being generated by 2D laser solitons, such 3D dissipative solitons in a laser cavity of length have a number of vortex lines, which are straight for under-critical values and spiral for larger . For supercritical , a vortex with multiple topological charges >1 in generating 2D solitons transforms into separate vortex lines. Read More

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Multiple double-pole bright-bright and bright-dark solitons and energy-exchanging collision in the M-component nonlinear Schrödinger equations.

Phys Rev E 2021 Jun;103(6-1):062214

Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong 518060, People's Republic of China.

Multiple double-pole bright-bright and bright-dark soliton solutions for the multicomponent nonlinear Schrödinger (MCNLS) system comprising three types of nonlinearities, namely, focusing, defocusing, and mixed (focusing-defocusing) nonlinearities, arising in different physical settings are constructed. An interesting type of energy-exchanging phenomenon during collision of these double-pole solitons is unraveled. To explore the objectives, we consider the general solutions of a set of generalized MCNLS equations and by taking the long-wavelength limit with proper parameter choices of single-pole bright-bright and bright-dark soliton pairs, the multiple double-pole bright-bright and bright-dark soliton solutions are constructed in terms of determinants. Read More

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Dynamic behaviors of multiple-soliton pulsation in an L-band passively mode-locked fiber laser with anomalous dispersion.

Chaos 2021 Jun;31(6):063122

International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China.

As a universal phenomenon in nonlinear optical systems, the soliton pulsating behavior is useful to achieve high pulse energy and can further enrich the complex soliton dynamics. To the best of our knowledge, herein we have demonstrated the observation of multiple-soliton pulsations in an L-band mode-locked fiber laser based on a nonlinear amplifying loop mirror with anomalous dispersion for the first time. Based on the dispersive Fourier transform method, we find that the pulsations in the multi-soliton regime are accompanied with the pulse width breathing and spectrum oscillation. Read More

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Orbital-angular-momentum-resolved diagnostics for tracking internal phase evolution in multi-bound solitons.

Opt Express 2021 May;29(11):16686-16694

The generation of multi-bound solitons is a fascinating subject of investigation in many conservative and dissipative systems, such as photonics, fluid mechanics, Bose-Einstein condensates, and so on. In this study, we demonstrate the successful extraction of phase dynamics between solitons in bound multiple solitons with up to seven constituents in a mode-locked Er laser system. By mapping the internal phase motions of multi-bound solitons to the spatial phase movement of cylindrical vector beams using orbital angular momentum (OAM)-based diagnostics, different categories of internal pulsations are revealed. Read More

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Multiple Self-Organized Phases and Spatial Solitons in Cold Atoms Mediated by Optical Feedback.

Phys Rev Lett 2021 May;126(20):203201

SUPA and Department of Physics, University of Strathclyde, Glasgow G4 0NG, Scotland, United Kingdom.

We study the transverse self-structuring of cold atomic clouds with effective atomic interactions mediated by a coherent driving beam retroreflected by means of a single mirror. The resulting self-structuring due to optomechanical forces is much richer than that of an effective-Kerr medium, displaying hexagonal, stripe and honeycomb phases depending on the interaction strength parametrized by the linear susceptibility. Phase domains are described by Ginzburg-Landau amplitude equations with real coefficients. Read More

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Synthesis and dissociation of soliton molecules in parallel optical-soliton reactors.

Light Sci Appl 2021 Jun 7;10(1):120. Epub 2021 Jun 7.

Max Planck Institute for the Science of Light Staudtstrasse 2, 91058, Erlangen, Germany.

Mode-locked lasers have been widely used to explore interactions between optical solitons, including bound-soliton states that may be regarded as "photonic molecules". Conventional mode-locked lasers normally, however, host at most only a few solitons, which means that stochastic behaviours involving large numbers of solitons cannot easily be studied under controlled experimental conditions. Here we report the use of an optoacoustically mode-locked fibre laser to create hundreds of temporal traps or "reactors" in parallel, within each of which multiple solitons can be isolated and controlled both globally and individually using all-optical methods. Read More

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Real-time observation of pulsating period-doubled vector solitons in a passively mode-locked fiber laser.

Opt Express 2021 Apr;29(9):14101-14111

Dissipative solitons (DSs) are self-organized localized structures in non-conservative systems, which require a continuous energy exchange with external sources. In addition to parameter-invariant stationary DSs, there exists a variety of dynamical ones manifesting breathing behaviors. Such intriguing phenomena, termed as soliton pulsations, have been widely studied in recent years under the impetus of advances in real-time spectroscopy. Read More

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Sensitivity assessment and optimal economic evaluation of a new COVID-19 compartmental epidemic model with control interventions.

Chaos Solitons Fractals 2021 May 20;146:110885. Epub 2021 Mar 20.

Department of Mathematics and Statistics, University of Energy and Natural Resources, Sunyani, Ghana.

Optimal economic evaluation is pivotal in prioritising the implementation of non-pharmaceutical and pharmaceutical interventions in the control of diseases. Governments, decision-makers and policy-makers broadly need information about the effectiveness of a control intervention concerning its cost-benefit to evaluate whether a control intervention offers the best value for money. The outbreak of COVID-19 in December 2019, and the eventual spread to other parts of the world, have pushed governments and health authorities to take drastic socioeconomic, sociocultural and sociopolitical measures to curb the spread of the virus, SARS-CoV-2. Read More

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Localized gap modes of coherently trapped atoms in an optical lattice.

Opt Express 2021 Feb;29(3):3011-3025

We theoretically investigate one-dimensional localized gap modes in a coherent atomic gas where an optical lattice is formed by a pair of counterpropagating far-detuned Stark laser fields. The atomic ensembles under study emerge as Λ-type three-level configuration accompanying the effect of electromagnetically induced transparency (EIT). Based on Maxwell-Bloch equations and the multiple scales method, we derive a nonlinear equation governing the spatial-temporal evolution of the probe-field envelope. Read More

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February 2021

An Emotion Care Model using Multimodal Textual Analysis on COVID-19.

Chaos Solitons Fractals 2021 Mar 22;144:110708. Epub 2021 Jan 22.

School of Mathematical Sciences, College of Science and Technology, Wenzhou-Kean University, Wenzhou, China.

At the dawn of the year 2020, the world was hit by a significant pandemic COVID-19, that traumatized the entire planet. The infectious spread grew in leaps and bounds and forced the policymakers and governments to move towards lockdown. The lockdown further compelled people to stay under house arrest, which further resulted in an outbreak of emotions on social media platforms. Read More

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Optimal control approach of a mathematical modeling with multiple delays of the negative impact of delays in applying preventive precautions against the spread of the COVID-19 pandemic with a case study of Brazil and cost-effectiveness.

Chaos Solitons Fractals 2021 Jan 4;142:110438. Epub 2020 Nov 4.

LAMS, Department of Mathematics and Computer Science, Faculty of Sciences Ben M'Sik, Hassan II University of Casablanca, Morocco.

As of June 02, 2020. The number of people infected with COVID-19 virus in Brazil was about 529,405, the number of death is 30046, the number of recovered is 211080, and the number is subject to increase. This is due to the delay by a number of countries in general, and Brazil in particular, in taking preventive and proactive measures to limit the spread of the COVID-19 pandemic. Read More

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January 2021

Observation of Universal Quench Dynamics and Townes Soliton Formation from Modulational Instability in Two-Dimensional Bose Gases.

Phys Rev Lett 2020 Dec;125(25):250401

Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA.

We experimentally study universal nonequilibrium dynamics of two-dimensional atomic Bose gases quenched from repulsive to attractive interactions. We observe the manifestation of modulational instability that, instead of causing collapse, fragments a large two-dimensional superfluid into multiple wave packets universally around a threshold atom number necessary for the formation of Townes solitons. We confirm that the density distributions of quench-induced solitary waves are in excellent agreement with the stationary Townes profiles. Read More

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December 2020

Real-time multispeckle spectral-temporal measurement unveils the complexity of spatiotemporal solitons.

Nat Commun 2021 Jan 4;12(1):67. Epub 2021 Jan 4.

School of Physics and Optoelectronics; State Key Laboratory of Luminescent Materials and Devices; Guangdong Engineering Technology Research and Development Center of Special Optical Fiber Materials and Devices; Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques, South China University of Technology, 381 Wushan Road, Guangzhou, 510640, China.

The dynamics of three-dimensional (3D) dissipative solitons originated from spatiotemporal interactions share many common characteristics with other multi-dimensional phenomena. Unveiling the dynamics of 3D solitons thus permits new routes for tackling multidisciplinary nonlinear problems and exploiting their instabilities. However, this remains an open challenge, as they are multi-dimensional, stochastic and non-repeatable. Read More

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January 2021

Intrinsical localization of both topological (anti-kink) envelope and gray (black) gap solitons of the condensed bosons in deep optical lattices.

Chaos 2020 Dec;30(12):123133

Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China.

By developing quasi-discrete multiple-scale method combined with tight-binding approximation, a novel quadratic Riccati differential equation is first derived for the soliton dynamics of the condensed bosons trapped in the optical lattices. For a lack of exact solutions, the trial solutions of the Riccati equation have been analytically explored for the condensed bosons with various scattering length a. When the lattice depth is rather shallow, the results of sub-fundamental gap solitons are in qualitative agreement with the experimental observation. Read More

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December 2020

Prediction of COVID-19 confirmed cases combining deep learning methods and Bayesian optimization.

Chaos Solitons Fractals 2021 Jan 28;142:110511. Epub 2020 Nov 28.

Faculty of Information Technology and Computer Engineering, Azarbaijan Shahid Madani University, Tabriz, Iran.

COVID-19 virus has encountered people in the world with numerous problems. Given the negative impacts of COVID-19 on all aspects of people's lives, especially health and economy, accurately forecasting the number of cases infected with this virus can help governments to make accurate decisions on the interventions that must be taken. In this study, we propose three hybrid approaches for forecasting COVID-19 time series methods based on combining three deep learning models such as multi-head attention, long short-term memory (LSTM), and convolutional neural network (CNN) with the Bayesian optimization algorithm. Read More

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January 2021

A survey on artificial intelligence approaches in supporting frontline workers and decision makers for the COVID-19 pandemic.

Chaos Solitons Fractals 2020 Dec 10;141:110337. Epub 2020 Oct 10.

Information Systems Group, Tallinn University of Technology, Akadeemia tee 15a, 12618, Tallinn, Estonia.

While the world has experience with many different types of infectious diseases, the current crisis related to the spread of COVID-19 has challenged epidemiologists and public health experts alike, leading to a rapid search for, and development of, new and innovative solutions to combat its spread. The transmission of this virus has infected more than 18.92 million people as of August 6, 2020, with over half a million deaths across the globe; the World Health Organization (WHO) has declared this a global pandemic. Read More

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December 2020

ZrSe nanosheet as saturable absorber for soliton operations within an Er-doped passive mode-locked fiber laser.

Appl Opt 2020 Sep;59(25):7484-7489

Two-dimensional materials have extensively promoted the development of ultrafast photonics in the past decade. In our work, the saturable absorption properties of were presented. The saturation intensity, modulation depth, and nonlinear absorption coefficient of the saturable absorber (SA) are about 13. Read More

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September 2020

The origin of spin wave pulse-induced domain wall inertia.

J Phys Condens Matter 2020 Sep 1;32(47):475803. Epub 2020 Sep 1.

School of Physical Science and Technology, Yangzhou University, Yangzhou 225002, People's Republic of China. Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea.

The fundamental problem of domain wall (DW) inertia-the property that gives to inertial behaviors remains unclear in the physics of magnetic solitons. To understand its nature as well as to achieve accurate DW positioning and efficient manipulation of domain wall motion (DWM), spin wave (SW) pulse-induced DW transient effect is studied both numerically and theoretically in a magnetic nanostrip. It is shown for the first time that there occurs inevitable deceleration/automotion after SW pulse, which indicates nonzero DW inertia. Read More

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September 2020

A quantitative framework for exploring exit strategies from the COVID-19 lockdown.

Chaos Solitons Fractals 2020 Nov 24;140:110244. Epub 2020 Aug 24.

Department of Mathematics and Statistics, University of Massachusetts, Amherst, MA 01003-4515, USA.

Following the highly restrictive measures adopted by many countries for combating the current pandemic, the number of individuals infected by SARS-CoV-2 and the associated number of deaths steadily decreased. This fact, together with the impossibility of maintaining the lockdown indefinitely, raises the crucial question of whether it is possible to design an exit strategy based on quantitative analysis. Guided by rigorous mathematical results, we show that this is indeed possible: we present a robust numerical algorithm which can compute the cumulative number of deaths that will occur as a result of increasing the number of contacts by a given multiple, using as input only the most reliable of all data available during the lockdown, namely the cumulative number of deaths. Read More

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November 2020

Data driven estimation of novel COVID-19 transmission risks through hybrid soft-computing techniques.

Chaos Solitons Fractals 2020 Nov 25;140:110152. Epub 2020 Jul 25.

Research Scholar, USBAS, GGS Indraprastha University, Delhi, India.

Coronavirus genomic infection-2019 (COVID-19) has been announced as a serious health emergency arising international awareness due to its spread to 201 countries at present. In the month of April of the year 2020, it has certainly taken the pandemic outbreak of approximately 11,16,643 infections confirmed leading to around 59,170 deaths have been recorded world-over. This article studies multiple countries-based pandemic spread for the development of the COVID-19 originated in the China. Read More

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November 2020

Applications of machine learning and artificial intelligence for Covid-19 (SARS-CoV-2) pandemic: A review.

Chaos Solitons Fractals 2020 Oct 25;139:110059. Epub 2020 Jun 25.

Department of Computing, Uiversity of York, Heslington, York, YO10 5DD, UK.

Background And Objective: During the recent global urgency, scientists, clinicians, and healthcare experts around the globe keep on searching for a new technology to support in tackling the Covid-19 pandemic. The evidence of Machine Learning (ML) and Artificial Intelligence (AI) application on the previous epidemic encourage researchers by giving a new angle to fight against the novel Coronavirus outbreak. This paper aims to comprehensively review the role of AI and ML as one significant method in the arena of screening, predicting, forecasting, contact tracing, and drug development for SARS-CoV-2 and its related epidemic. Read More

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October 2020

A novel mathematical approach of COVID-19 with non-singular fractional derivative.

Chaos Solitons Fractals 2020 Oct 1;139:110048. Epub 2020 Jul 1.

Department of Mathematics, Faculty of Sciences, Sohag University, Sohag 82524, Egypt.

We analyze a proposition which considers new mathematical model of COVID-19 based on fractional ordinary differential equation. A non-singular fractional derivative with Mittag-Leffler kernel has been used and the numerical approximation formula of fractional derivative of function is obtained. A new operational matrix of fractional differentiation on domain [0, ],  ≥ 1,  ∈  by using the extended Legendre polynomial on larger domain has been developed. Read More

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October 2020

Soliton formation and stability under the interplay between parity-time-symmetric generalized Scarf-II potentials and Kerr nonlinearity.

Phys Rev E 2020 Jul;102(1-1):012216

Department of Theoretical Physics, Horia Hulubei National Institute for Physics and Nuclear Engineering, Bucharest-Magurele, RO-077125, Romania.

We present an alternative type of parity-time (PT)-symmetric generalized Scarf-II potentials, which makes possible for non-Hermitian Hamiltonians in the classical linear Schrödinger system to possess fully real spectra with unique features such as the multiple PT-symmetric breaking behaviors and to support one-dimensional (1D) stable PT-symmetric solitons of power-law waveform, namely power-law solitons, in focusing Kerr-type nonlinear media. Moreover, PT-symmetric high-order solitons are also derived numerically in 1D and 2D settings. Around the exactly obtained nonlinear propagation constants, families of 1D and 2D localized nonlinear modes are also found numerically. Read More

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Magnetic Solitons in a Spin-1 Bose-Einstein Condensate.

Phys Rev Lett 2020 Jul;125(3):030402

School of Physics, Georgia Institute of Technology, 837 State Street, Atlanta, Georgia 30332, USA.

Vector solitons are a type of solitary or nonspreading wave packet occurring in a nonlinear medium composed of multiple components. As such, a variety of synthetic systems can be constructed to explore their properties, from nonlinear optics to ultracold atoms, and even in metamaterials. Bose-Einstein condensates have a rich panoply of internal hyperfine levels, or spin components, which make them a unique platform for exploring these solitary waves. Read More

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Observation of Magnetic Solitons in Two-Component Bose-Einstein Condensates.

Phys Rev Lett 2020 Jul;125(3):030401

INO-CNR BEC Center and Dipartimento di Fisica, Università di Trento, and Trento Institute for Fundamental Physics and Applications, INFN, 38123 Povo, Italy.

We experimentally investigate the dynamics of spin solitary waves (magnetic solitons) in a harmonically trapped, binary superfluid mixture. We measure the in situ density of each pseudospin component and their relative local phase via an interferometric technique we developed and as such, fully characterize the magnetic solitons while they undergo oscillatory motion in the trap. Magnetic solitons exhibit nondispersive, dissipationless longtime dynamics. Read More

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Functional all-optical logic gates for true time-domain signal processing in nonlinear photonic crystal waveguides.

Opt Express 2020 Jun;28(12):18317-18331

We present a conceptual study on the realization of functional and easily scalable all-optical NOT, AND and NAND logic gates using bandgap solitons in coupled photonic crystal waveguides. The underlying structure consists of a planar air-hole type photonic crystal with a hexagonal lattice of air holes in crystalline silicon (c-Si) as the nonlinear background material. The remaining logical operations can be performed using combinations of these three logic gates. Read More

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Control of topology of two-dimensional solitons in a laser with saturable absorption by means of a coherent holding radiation.

Opt Lett 2020 Jun;45(12):3284-3287

We propose a simple method to control the topology of laser vortex solitons and their complexes in a wide-aperture laser with saturable absorption by means of weak coherent holding radiation. The holding radiation acting on initial "free" vortex solitons induces the appearance of new peripheral vortices and the splitting of multiple central vortices, as well as reconfiguration of energy flow topology. A wide variety of these stable vortex structures makes the scheme promising for topologically protected information processing. Read More

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Real-time forecasts and risk assessment of novel coronavirus (COVID-19) cases: A data-driven analysis.

Chaos Solitons Fractals 2020 Jun 30;135:109850. Epub 2020 Apr 30.

AERU, Indian Statistical Institute, 203, B. T. Road, Kolkata 700108, India.

The coronavirus disease 2019 (COVID-19) has become a public health emergency of international concern affecting 201 countries and territories around the globe. As of April 4, 2020, it has caused a pandemic outbreak with more than 11,16,643 confirmed infections and more than 59,170 reported deaths worldwide. The main focus of this paper is two-fold: (a) generating short term (real-time) forecasts of the future COVID-19 cases for multiple countries; (b) risk assessment (in terms of case fatality rate) of the novel COVID-19 for some profoundly affected countries by finding various important demographic characteristics of the countries along with some disease characteristics. Read More

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Vortex soliton molecule in a fiber laser.

Opt Express 2020 Mar;28(7):9666-9676

We report the generation of vortex soliton molecules (VSMs) in a passively mode-locked fiber laser based on a mode selective coupler (MSC). ±1-order VSMs with variable numbers of molecules are observed. By adjusting the polarization state of the light in the cavity, we further demonstrate the process in which one VSM splits to multiple. Read More

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