Propagation In Optical Fibers Research Articles

Qualitative analysis of stochastic Schrödinger–Hirota equation in birefringent fibers with spatiotemporal dispersion and parabolic law nonlinearity

In this paper, the stochastic Schrödinger–Hirota equation in birefringent fibers with spatiotemporal dispersion and parabolic law nonlinearity is studied, which is usually used to describe the mathematical model of optical soliton propagation in dispersive optical fibers from the field of nonlinear optics. Firstly, the stochastic Schrödinger–Hirota equation is converted into two-dimensional planar dynamic system by using the traveling wave transformation. Secondly, the qualitative analysis of the stochastic Schrödinger–Hirota equation is discussed by using the theory of planar dynamical systems. Finally, the chaos pattern of the stochastic Schrödinger–Hirota equation with perturbed system is considered. What is more, phase portraits and sensitivity analysis of the perturbed system are plotted by using the Maple software.

All-fiber spatial profile and polarization controller

The spin and orbital angular momentum of photons can perturb during propagation in few mode optical fiber, and hence, in the receiver, perturbations must be adjusted. For polarization adjustment, polarization controllers have been developed previously. In this paper, we show that in the presence of external effects such as tension and tortion, the entanglement between the different degrees of freedom of a photon does not change. A device for simultaneous adjustment of polarization and spatial distribution in few mode fiber is proposed. In addition to modification, this device can also be used to produce different modes in fiber.

Traveling Wave Optical Solutions for the Generalized Fractional Kundu–Mukherjee–Naskar (gFKMN) Model

The work considers traveling wave optical solutions for the nonlinear generalized fractional KMN equation. This equation is considered for describing pulse propagation in optical fibers and communication systems using two quite similar approaches, based on the expansion of these solutions in the exponential or polynomial forms. Both approaches belong to the direct solving class of methods for PDEs and suppose the use of an auxiliary equation. The solutions acquired in this paper are obtained from first- and second-order differential equations that act as auxiliary equations. In addition, we generated 3D, contour, and 2D plots to illustrate the characteristics of the obtained soliton solutions. To create these plots, we carefully selected appropriate values for the relevant parameters.

On the dynamics of a dual space–time fractional nonlinear Schrödinger model in optical fibers

The nonlinear Schrödinger equation (NLSE) is a significant nonlinear complex model known as the most important struture to represent light pulse propagation in optical fibers, which plays a key role in demonstrating the proliferation specifically short pulse in optical fibers and have large appliances in telecommunication system and ultra fast signal routing in nonlinear optics. In this study, we look into explicit solutions of a coupled fractional NLSE for a dual space–time, which reflect numerous explicit travelling wave solutions, as well as their physical interpretation. We use the fractional complex transform to obtain multiple exact answers using the unified technique and the extended simple equation method. These exact answers include trigonometric function solutions as well as dark, bright, singular, periodic, and optical soliton solutions. For a set of appropriate parameters, Mathematica is used to represent the dynamics of various wave structures as 3D, 2D, and contour visualizations. These findings show that the proposed methodologies are simple, prolific, and capable of studying the nature of numerous physical models of complex phenomena in modern science.

Soliton structures for a generalized unstable space–time fractional nonlinear Schrödinger model in mathematical physics

One of the most important physical models for describing the dynamics of optical soliton propagation in the theory of optical fibers is the nonlinear Schrödinger equation (NLSE). Since there are so many uses for ultrafast signal routing systems and brief light pulses in telecommunication, optical soliton propagation in nonlinear optical fibers is a subject of intense current interest. The conventional Khater approach and the extended direct algebraic method are used in this research to study a generalized unstable space–time fractional NLS model in mathematical physics. This leads to the discovery of solutions for the bright, dark, periodic, rational and elliptic functions. To illustrate the physical nature of the nonlinear model, the contour plots in 3D, 2D and 2D are produced by assigning the appropriate values to the arbitrary constants. Additionally, consideration is given to the stability analysis of the solutions to the governing equation. In the current era of communications network technology and nonlinear optics, the applied strategy appears to be a more potent and effective way for producing precise optical solutions to a number of various modern models of recent generations.

Nonlinear autoregressive with external input neural network for predicting the nonlinear dynamics of supercontinuum generation in optical fibers

Full characterization of the propagation dynamics of ultra-short pulses in optical fibers is of fundamental importance in designing optical devices for several applications in the nonlinear optics field. Such applications range from basic descriptions of the light–matter dynamics to Bose–Einstein condensates, plasma physics, hydrodynamics, high-resolution imaging, and remote sensing, among many others. Nevertheless, ultra-short pulse propagation is a highly nonlinear process, so correctly describing all temporal and spectral features of these pulses is a big challenge, consuming extensive computational resources. Looking for simple solutions to this problem, we present in this paper, for the first time, to the best of our knowledge, a nonlinear autoregressive with external input neural network (NARXNET) capable of predicting the nonlinear dynamics of supercontinuum generation in optical fibers. The NARXNET structure allows low prediction error, fast training as short as 1.45 min, satisfactory generalization ability, and low computational resources for the training and testing stages.

Dynamical behaviors of solitons for NLSE with Kudryashov’s sextic power-law of nonlinear refractive index using improved modified extended tanh-function method

The higher order nonlinear Schrödinger equation (NLSE) describes ultrashort pulse propagation in optical fibres. In this paper, we discuss analytically the non-linear schrödinger equation with higher order dispersion terms up to sixth order and sextic power law of nonlinearity with the help of the improved modified extended tanh-function scheme. New families of solutions, such as dark solitons, singular solitons, rational solutions, periodic solutions and exponential type solutions, have been extracted. Extracted solutions will be useful in the development of the communication systems. Furthermore, some solutions are graphically depicted to demonstrate their physical nature by using distinct values of the parameters.

Solitons collision and multi-peak solutions for a new $$(3+1)$$-dimensional NLSE describing pulse propagation in optical fibers

Solitons collision and multi-peak solutions for a new $$(3+1)$$-dimensional NLSE describing pulse propagation in optical fibers

Comparison of supercontinuum spectral widths in CCl4-core PCF with square and circular lattices in the claddings

In this study, we demonstrate the ability to generate a broad supercontinuum (SC) spectrum with a low peak power of square (S-PCF) and circular (C-PCF) lattice photonic crystal fibers with hollow-core infiltrated with carbon tetrachloride (CCl4). The dispersion and nonlinear characteristics have been numerically analyzed in detail and compared to select the optimal structures for SC generation and evaluate the SC generation efficiency for each PCF. With four optimal proposed structures, the all-normal dispersion of square PCF (#SF1) is found to be flatter and smaller. This results in its SC bandwidth reaching 901 nm at 1.095 μm pumping wavelength which is broader than that of circular PCF (#CF1) (768 nm at 0.98 μm wavelength) despite the lower nonlinear coefficient and higher confinement loss. For the anomalous dispersion regime, #CF2 fiber provides a wider SC spectrum (1753.1 nm) with a peak power of 10 kW compared to #SF2 (1689.6 nm) with a peak power of 13.75 kW thanks to the higher nonlinear coefficient and smaller confinement loss. With the higher nonlinearity of CCl4, the proposed fibers can be a new generation of optical fibers, suitable for low peak power all-fiber optical systems replacing glass core fibers.

Novel soliton wave solutions of a special model of the nonlinear Schrödinger equations with mixed derivatives

In this study, the influence of the integrability requirement on nonlinear Schrödinger equations with mixed derivatives is examined. The Rangwala–Rao (RR) equation is named after A. Rangwala, who in 1990 was the first to quantify these effects in their entirety. The aim of our research is identifying how to generate individual waves and how they interact with one another. This is to get a better understanding of the dispersion effect and the progressive variation of the electric field envelope during pulse propagation in optical fibers. The direct algebraic method (DAM), the extended direct algebraic approach (exDAA), and the extended Riccati expansion technique (exREM) are used to develop unique solitary wave solutions for the model under consideration. These numerically calculated solutions illustrate the dynamic behavior of an optical pulse traveling through a cable. Comparing our results to those of other researchers demonstrates the originality of our work.

Predicting the evolution of the mid-infrared supercontinuum in the near-zero dispersion region under weak triggering using LSTM neural networks

To enable active control of rogue waves after pumping a pulse into an optical fiber, adding a weak trigger is necessary. However, this process typically involves numerous numerical simulations based on the nonlinear Schrodinger equation, which can be computationally intensive. Using neural networks to predict complex nonlinear propagation in optical fibers avoids the need for numerical solutions during research. We show a neural network using long short-term memory to predict the temporal and spectral evolutions of the mid-infrared supercontinuum generation in the near-zero dispersion region under weak triggering, simply by determining the input pulse strength in the time and frequency domains.

Bifurcation analysis, stationary optical solitons and exact solutions for generalized nonlinear Schrödinger equation with nonlinear chromatic dispersion and quintuple power-law of refractive index in optical fibers

In this paper, the bifurcation, stationary optical solitons and exact solutions in optical fiber propagation are studied. The propagation model is described by a generalized nonlinear Schrödinger equation with Kudryashov’s quintuple power law of refractive index. First, the equation is transformed into a second-order nonlinear ordinary differential equation by an appropriate transformation. Then, the bifurcation of the phase diagram of the obtained ordinary differential equation is established using planar dynamic system theory, and the types of optical solitons and exact solutions are determined. What is more, the stationary optical solitons and exact solutions are obtained by the polynomial complete discriminant system, and are demonstrated in 3D and 2D graphics by using the symbolic computation software Maple. Finally, the obtained stationary optical solitons and exact solutions include the Jacobi elliptic function solution, hyperbolic function solution, rational function solution, trigonometric function solution and exponential function solution. Moreover, the results provide a method to further study stationary optical solitons and exact solutions of propagation pulses in optical fibers.

Soliton dynamics in optical fiber based on nonlinear Schrödinger equation

Optical fiber is a component of the green and sustainable internet. This paper analyzes the energy loss induced by the attenuation effect of electromagnetic waves during optical fiber propagation. The dynamics of the Hamiltonian, which was derived using the dynamics of the solution the Nonlinear Schrödinger equation (NLS) problem, were used to investigate the energy drop. In this study, the Newton-Raphson (NR) approach was used to establish the stationary solution of the NLS problem, and the fourth order Runge-Kutta method was used to evaluate the dynamics of the solution (RK4). In this study, numerous parameters are adjusted, including group wave dispersion, nonlinearity, attenuation parameter, and potential trap. The solution of the NR approach is fairly close to the analytical solution based on the analytical solutions. The dynamics of the NLS equation solution are greatly influenced by parameters. The obtained results reveal that for large attenuation parameter values, the strength of the propagating electromagnetic waves decreases quite quickly. The result also shows that the other parameters studied must be maintained at the best conditions to support the attenuation parameters and potential trap. This condition is an indicator in the choice of the fundamental material for producing optical fiber, which should have a low attenuation and dispersion effect.

Estimate the Attenuation and Simulation of dispersion Gaussian pulses propagation in a Single Mode Optical Fiber

we studied Attenuation in Fiber Optics, we used two type of Fibers (Plastic and glass) with length (0.5,5,20m) and (1,20,100m) respectively and used two wavelength laser (660nm, 850nm), we found attenuation increase with 850nm wavelength and 660nm wavelength are the best for the plastic fiber optics, in addition the attenuation which occur from axial gap, axes rotation, inclination angle, transversal displacement are investigated. Influence three values of linear dispersion on Pulse propagation along fiber at seam distance is investigated by simulation using Fourier Method using MATLAB.

Innovative and diverse soliton solutions of the dual core optical fiber nonlinear models via two competent techniques

It becomes an interesting part for the researchers to analyze the dynamical behavior of soliton propagation in optical fibers for trans-oceanic and trans-continental distances. In this paper, we desire to retrieve distinct and innovative accurate wave solutions to the dual core optical fiber nonlinear equations by adopting the improved tanh method and the rational [Formula: see text]-expansion method. Consequently, a bundle of accurate wave solutions is achieved in diverse sense. The acquired solutions are made visible in the profiles of three-dimensional (3D), two-dimensional (2D) and contour shapes. The effects of the wave speed in soliton transmission are highlighted by plotting different 2D outlines in a single diagram for some obtained solutions. The employed techniques perform as before to unravel the suggested governing models for appropriate wave solutions and hence deserve to contribute in further research.

The Applications of Digital Signal Processing Techniques for Enhancing the Performance of High Speed Optical Communication Systems

This paper presents Improving performance of 112 Gbits optical coherent communications systems using digital signal processing techniques to compensate linear impairments that are exposed to the signal during its propagation in optical fiber. In this paper, different multi-level modulation formats (DP-QPSK, DP 8PSK, DP- 16PSK and DP-16-QAM) were compared for the same data rate at different distances from the transmitter without amplification. the comparison was done by measuring bit error rate value. We used digital signal processing techniques for linear effects compensation. Where chromatic dispersion was compensated using a simple digital filter, and Polarization mod dispersion was realized by applying the constant-modulus algorithm (CMA). The phase and frequency mismatch between the transmitter and the local oscillator in the receiver was compensated using the modified Viterbi-Viterbi algorithm. We used the Optical simulator Opti-system , which was linked with MATLAB R2011 in order to implementation DSP algorithms and analyze obtained results.

New single traveling wave solution of the Fokas system via complete discrimination system for polynomial method

<abstract> <p>In this paper, the traveling wave solution of the Fokas system which represents the irregular pulse propagation in monomode optical fibers is studied by using the complete discriminant system method of polynomials. Firstly, the Fokas system is simplified into nonlinear ordinary differential equations by using the traveling wave transformation. Secondly, the Jacobian function solutions, the trigonometric function solutions, the hyperbolic function solutions and the rational function solution of Fokas system are obtained by using the complete discriminant system method of polynomials. Finally, in order to show the propagation of Fokas system in monomode optical fibers, three-dimensional diagram, two-dimensional diagram, contour plot and density plot of some solutions are drawn by using Maple software.</p> </abstract>

Construction of Novel Bright-Dark Solitons and Breather Waves of Unstable Nonlinear Schrödinger Equations with Applications

The unstable nonlinear Schrödinger equations (UNLSEs) are universal equations of the class of nonlinear integrable systems, which reveal the temporal changing of disruption in slightly stable and unstable media. In current paper, an improved auxiliary equation technique is proposed to obtain the wave results of UNLSE and modified UNLSE. Numerous varieties of results are generated in the mode of some special Jacobi elliptic functions and trigonometric and hyperbolic functions, many of which are distinctive and have significant applications such as pulse propagation in optical fibers. The exact soliton solutions also give information on the soliton interaction in unstable media. Furthermore, with the assistance of the suitable parameter values, various kinds of structures such as bright-dark, multi-wave structures, breather and kink-type solitons, and several periodic solitary waves are depicted that aid in the understanding of the physical interpretation of unstable nonlinear models. The various constructed solutions demonstrate the effectiveness of the suggested approach, which proves that the current technique may be applied to other nonlinear physical problems encountered in mathematical physics.

Method of Line Solution of Optical Soliton in Optical Communication System

The performance of fiber-optic communication is constrained by the dispersive phenomenon of group velocity dispersion (GVD) and fiber non-linearity of self-phase modulation, but when these effects are balanced, a single wave or soliton is produced. A soliton can travel a great distance with constant speed. It is suitable for use in ultra-long-distance communication because of these unique features. The non-linear Schrodinger (NLS) equation describes the optical soliton propagation in optical fibers. By using the method of line (MOL) to solve the NLS equation, this study mimics the optical soliton propagation. It demonstrates that during simulations at 400 km, the optical soliton maintains its shape and amplitude.

Computational Traveling Wave Solutions of the Nonlinear Rangwala–Rao Model Arising in Electric Field

The direct influence of the integrability requirement on mixed derivative nonlinear Schrödinger equations is investigated in this paper. A. Rangwala mathematically formalized these effects in 1990 and dubbed this form the Rangwala–Rao (RR) equation. Our research focuses on innovative soliton wave solutions and their interactions in order to provide a clear picture of the slowly evolving envelope of the electric field and pulse propagation in optical fibers in terms of the dispersion effect. For creating unique solitary wave solutions to the investigated model, three contemporary computational strategies (extended direct (ExD) method, improved F–expansion (ImFE) method, and modified Kudryashov (MKud) method) are employed. These solutions are numerically computed to demonstrate the dynamical behavior of optical fiber pulse propagation. The originality of the paper’s findings is proved by comparing our results to previously published results.