Effective regulation of the interaction process among three optical solitons

The interaction between three optical solitons is a complex and valuable research direction,which is of practical application for promoting the development of optical communication and all-optical information processing technology.In this paper,we start from the study of the variable-coefficient coupled higher-order nonlinear Schodinger equation(VCHNLSE),and obtain an analytical three-soliton solution of this equation.Based on the obtained solution,the interaction of the three optical solitons is explored when they are incident from different initial velocities and phases.When the higher-order dispersion and nonlinear functions are sinusoidal,hyperbolic secant,and hyperbolic tangent functions,the transmission properties of three optical solitons before and after interactions are discussed.Besides,this paper achieves effective regulation of amplitude and velocity of optical solitons as well as of the local state of interaction process,and interaction-free transmission of the three optical solitons is obtained with a small spacing.The relevant conclusions of the paper are of great significance in promoting the development of high-speed and large-capacity optical communication,optical signal processing,and optical computing.

Ultraslow Optical Solitons in a Coupled Double Quantum-Well Nanostructure

We demonstrate the formation of ultraslow dark semiconductor double quantum well （SDQW） structure based optical solitons with a four-level scheme in an asymmetric on intersubband transitions by using only a low-intensity pulsed laser radiation. With appropriate conditions we show numerically that the dark optical soliton can travel with a ultraslow group velocity Vg/c - -10^-3. Such a semiconductor system is much more practical than its atomic counterpart because of its flexible design and the controllable interference strength. This nonlinear optical process in the SDQW solid-state material may be used for the control technology of optical delay lines and optical buffers.

Ultraslow optical solitons via electromagnetically induced transparency:a density-matrix approach

We study the ultraslow optical solitons in a resonant three-level atomic system via electromagnetically induced transparency under a density-matrix （DM） approach. The results of linear and nonlinear optical properties are compared with those obtained by using an amplitude variable （AV） approach. It is found that the results for both approaches are the same in the linear regime if the corresponding relations between the population-coherence decay rates in the DM approach and the energy-level decay rates in the AV approach are appropriately imposed. However, in the nonlinear regime there is a small difference for the self-phase modulation coefficient of the nonlinear SchrSdinger equation that governs the time evolution of probe pulse envelope. All analytical predicts are checked by numerical simulations.

Hybrid Dispersive Optical Solitons in Nonlinear Cubic-Quintic-Septic Schrödinger Equation

Certain hybrid prototypes of dispersive optical solitons that we are looking for can correspond to new or future behaviors, observable or not, developed or will be developed by optical media that present the cubic-quintic-septic law coupled, with strong dispersions. The equation considered for this purpose is that of non-linear Schrödinger. The solutions are obtained using the Bogning-Djeumen Tchaho-Kofané method extended to the new implicit Bogning’ functions. Some of the obtained solutions show that their existence is due only to the Kerr law nonlinearity presence. Graphical representations plotted have confirmed the hybrid and multi-form character of the obtained dispersive optical solitons. We believe that a good understanding of the hybrid dispersive optical solitons highlighted in the context of this work allows to grasp the physical description of systems whose dynamics are governed by nonlinear Schrödinger equation as studied in this work, allowing thereby a relevant improvement of complex problems encountered in particular in nonliear optaics and in optical fibers.

Fractional Optical Solitons and Fractional Noether’s Theorem with Ortigueira’s Centered Derivatives

This paper shows that the centered fractional derivatives introduced by Manuel Duarte Ortigueira in 2006 are useful in the description of optical solitons. It is shown that we can construct a fractional extension of the nonlinear Schrödinger (NLS) equation which incorporates Ortigueira’s derivatives and has soliton solutions. It is also shown that this fractional NLS equation has a Lagrangian density and can be derived from a variational principle. Finally, a fractional extension of Noether’s theorem is formulated to determine the conserved quantities associated to the invariances of the action integral under infinitesimal transformations.

High-order effect on the transmission of two optical solitons

For optical solitons with the pulse width in the subpicosecond and femtosecond scales in optical fibers,a modified model containing higher-order effects such as third-order dispersion and third-order nonlinearity is needed.In this paper,in order to study the dynamic mechanism of femtosecond solitons in different media,we take the nonlinear Schr?dinger equation considering higher-order effects as the theoretical model,discuss the propagation of solitons in single-mode fibers,and explore the third-order dispersion and third-order nonlinear effects on the generation of optical solitons.The exact solution of the theoretical model is obtained through the bilinear method,and the transmission characteristics of two solitons with exact soliton solutions in actual fiber systems are analyzed and studied.The influence of various conditions on the transmission and interaction of optical solitons is explored.Methods for optimizing the transmission characteristics of optical solitons in optical communication systems are suggested.The relevant conclusions of this paper have guiding significance for improving the quality of fiber optic communication and increasing bit rates.

Optical solitons supported by finite waveguide lattices with diffusive nonlocal nonlinearity

We investigate the properties of fundamental,multi-peak,and multi-peaked twisted solitons in three types of finite waveguide lattices imprinted in photorefractive media with asymmetrical diffusion nonlinearity.Two opposite soliton selfbending signals are considered for different families of solitons.Power thresholdless fundamental and multi-peaked solitons are stable in the low power region.The existence domain of two-peaked twisted solitons can be changed by the soliton self-bending signals.When solitons tend to self-bend toward the waveguide lattice,stable two-peaked twisted solitons can be found in a larger region in the middle of their existence region.Three-peaked twisted solitons are stable in the lower(upper)cutoff region for a shallow(deep)lattice depth.Our results provide an effective guidance for revealing the soliton characteristics supported by a finite waveguide lattice with diffusive nonlocal nonlinearity.

Adjusting amplitude of the stored optical solitons by inter-dot tunneling coupling in triple quantum dot molecules

We study the propagation properties of a probe field in an aligned asymmetric triple quantum dot molecule with both sides inter-dot tunneling coupling effect. It is shown that the probe field can form optical soliton due to the destructive quantum interference induced by the quantum inter-dot tunneling coupling effect. Interestingly, these optical solitons can be stored and retrieved by adjusting single or double inter-dot tunneling coupling effect, different from that light memory in the ultra-cold atom system. Furthermore, we also find that the amplitude of the stored optical soliton can be adjusted by the strength of the single or double inter-dot tunneling coupling. It is possible to improve the stability and the fidelity of the optical information in the process of the storage and retrieval in semiconductor quantum dots devices.

Coupled Optical Solitons for Pulse Propagation in Multi-Level Media

We investigate the shape-preserving propagation of N optical pulses in an （N ＋ 1）-level medium. We solve Maxwell-Schroedinger equations exactly and provide several types of explicit coupled soliton solutions, which are temporally amplitude- and group-velocity-matched multi-mode slow-optical pulses of the system.

Ultraslow optical solitons in tunnel-coupled double semiconductor quantum well

This paper investigates the nonlinear evolution of the pulse probe field in an asymmetric coupled-quantum well driven coherently by a pulse probe field and two controlled fields. This study shows that, by choosing appropriate physical parameters, self-modulation can precisely balance group velocity dispersion in the investigated system, leading to the formation of ultraslow optical solitons of the probe field. The proposed scheme may lead to the development of the controlled technique of optical buffers and optical delay lines.

Self—Steepening and Thired—Order Dispersion Induced Optical Solitons in Fiber

Usually,one considers only the group velocity dispersion(GVD)-and self-phase modulation(SPM)-induced solitons in optic soliton communication while other higher order effects such as the third-order dispersion(TOD),self-steepening(SS),and stimulated Raman scattering are considered only perturbatively,In this paper,we study the existence of the TOD-and SS-induced soliton solutions.The existence conditions of the TOD-and SS-induced bright and dark solitons are quite different from those of the GVD-and SPM-induced solitons.

Numerical Analyses Optical Solitons in Dual Core Couplers with Kerr Law Nonlinearity

In this paper, we present the results of numerical analysis of optical solitons in dual core couplers. We studied the optical couplers as an application for the non-linear Schrödinger equation in the case of Kerr law for non-linear and clarify the exact solution in this case. Then we have provided a numerical study of the effect of changing the constants in the form of the three types of solitons: bright soliton and dark solitons and singular soliton.

Controllable Optical Solitons in Optical Fiber System with Distributed Coefficients

We present how to control the dynamics of optical solitons in optical fibers under nonlinearity and dispersion management, together with the fiber loss or gain. We obtain a family of exact solutions for the nonlinear Schrfidinger equation, which describes the propagation of optical pulses in optical fibers, and investigate the dynamical features of solitons by analyzing the exact analytical solutions in different physical situations. The results show that under the appropriate condition, not only the group velocity dispersion and the nonlinearity, but also the loss/gain can be used to manipulate the light pulse.

Asymptotic analysis on bright solitons and breather solutions of a generalized higher-order nonlinear Schrödinger equation in an optical fiber or a planar waveguide

We study a generalized higher-order nonlinear Schr¨odinger equation in an optical fiber or a planar waveguide.We obtain the Lax pair and N-fold Darboux transformation(DT)with N being a positive integer.Based on Lax pair obtained by us,we derive the infinitely-many conservation laws.We give the bright one-,two-,and N-soliton solutions,and the first-,second-,and Nth-order breather solutions based on the N-fold DT.We conclude that the velocities of the bright solitons are influenced by the distributed gain function,g(z),and variable coefficients in equation,h1(z),p1(z),r1(z),and s1(z)via the asymptotic analysis,where z represents the propagation variable or spatial coordinate.We also graphically observe that:the velocities of the first-and second-order breathers will be affected by h1(z),p1(z),r1(z),and s1(z),and the background wave depends on g(z).

Optical solitons for the decoupled nonlinear Schr?dinger equation using Jacobi elliptic approach

Most of the important aspects of soliton propagation through optical fibers for transcontinental and transoceanic long distances can best be described using the nonlinear Schr?dinger equation.Optical solitons are electromagnetic waves that span in nonlinear dispersive media and permit the stress and intensity to stay unaltered as a result of the delicate balance between dispersion and nonlinearity effects.However,this study exploited the Jacobi elliptic method and obtained different soliton solutions of the decoupled nonlinear Schr?dinger equation with ease.Discussions about the obtained solutions were made with the aid of some 3D graphs.

Bright and dark optical solitons in the nonlinear Schrdinger equation with fourth-order dispersion and cubic-quintic nonlinearity

By the use of an auxiliary equation, we find bright and dark optical soliton and other soliton solutions for the higher-order nonlinear Schrodinger equation (NLSE) with fourth-order dispersion (FOD), cubic-quintic terms, self-steepening, and nonlinear dispersive terms. Moreover, we give the formation condition of the bright and dark solitons for this higher-order NLSE.

Storage and retrieval of ultraslow optical solitons in coherent atomic system

We investigate the propagation of intense probe pulses in a lifetime broadened A-type three-level atomic system with a configuration of electromagnetically induced transparency. We find that ultraslow optical solitons formed by a balance between dispersion and nonlinearity can be stored and retrieved in the system by switching off and on a control field. Such pulses are robust during storage and retrieval, and hence may have potential applications in optical and quantum information processing.

Diverse chirped optical solitons and new complex traveling waves in nonlinear optical fibers

This paper studies chirped optical solitons in nonlinear optical fibers.However,we obtain diverse soliton solutions and new chirped bright and dark solitons,trigonometric function solutions and rational solutions by adopting two formal integration methods.The obtained results take into account the different conditions set on the parameters of the nonlinear ordinary differential equation of the new extended direct algebraic equation method.These results are more general compared to Hadi et al(2018 Optik 172545–53)and Yakada et al(2019 Optik197163108).

Effect of interaction strength on gap solitons of Bose-Einstein condensates in optical lattices

We have developed a systematic analytical approach to the study on the dynamic properties of the linear and the nonlinear excitations for quasi-one-dimensional Bose-Einstein condensate trapped in optical lattices. A novel linear dispersion relation and an algebraic soliton solution of the condensate are derived analytically under consideration of Bose-Einstein condensate with a periodic potential. By analysing the soliton solution, we find that the interatomic interaction strength has an important effect on soliton dynamic properties of Bose-Einstein condensate.

The impact of temperature on the evolution and self-deflection of spatial optical solitons in photovoltaic photorefractive media

The temperature effects on the evolution and self-deflection of bright spatial optical solitons in photo-voltaic photorefractive media were investigated by taking into account diffusion effects. The numerical results show that the evolution of the bright solitary beam depends strongly on the crystal temperature. It is also found that the bending distance of the bright solitary beam centre increases and reaches its maximum value at a characteristic temperature, and then decreases as temperature rises and ap-proaches zero at low and high temperatures. Both the maximum value and characteristic temperature increase with the input power density. The self-deflection of bright solitary beam is further studied by a perturbation technique, and the results are found to be in good agreement with that obtained by the numerical method. The diffusion process and the dark irradiance dominate the temperature depend-ence of bending distance in most values of temperature besides at the characteristic temperature and in the higher temperature regime. The diffusion process will mainly dominate the temperature dependence at the characteristic temperature and the dark irradiance will dominate in the higher tem-perature range.