Dynamics Of Optical Pulses Research Articles

Exploring the physical characteristics and nonlinear wave dynamics of a (3+1)-dimensional integrable evolution system

This study comprehensively explores the [Formula: see text]-dimensional Mikhailov–Novikov–Wang [Formula: see text] integrable equation, with the primary objective of elucidating its physical manifestations and establishing connections with analogous nonlinear evolution equations. The investigated model holds significant physical meaning across various disciplines within mathematical physics. Primarily, it serves as a fundamental model for understanding nonlinear wave propagation phenomena, offering insights into wave behaviors in complex media. Moreover, its relevance extends to nonlinear optics, where it governs the dynamics of optical pulses and solitons crucial for optical communication and signal processing technologies. Employing analytical methodologies, namely the unified [Formula: see text], Khater II ([Formula: see text]hat.II) method, and He’s variational iteration [Formula: see text] method, both numerical and analytical solutions are meticulously examined. Through this investigation, the intricate behaviors of the equation are systematically unveiled, shedding illuminating insights on various physical phenomena, notably including wave propagation in complex media and nonlinear optics. The outcomes not only underscore the efficacy of the analytical techniques deployed but also accentuate the equation’s pivotal role in modeling a broad spectrum of nonlinear wave dynamics. Consequently, this research significantly advances our comprehension of complex physical systems governed by nonlinear dynamics, thereby contributing notably to interdisciplinary pursuits in mathematical physics.

Dynamics of optical pulses with the effect of second-order spatiotemporal dispersion

Dynamics of optical pulses with the effect of second-order spatiotemporal dispersion

Frequency‐Resolved Optical Gating in Transverse Geometry for On‐Chip Optical Pulse Diagnostics

AbstractA new on‐chip diagnostic tool is developed, allowing for real‐time full characterization of waveguided ultrashort optical pulses. This technique, called transverse frequency‐resolved optical gating (T‐FROG), relies on second harmonic generation (SHG) in a transverse (surface emitting) geometry. The T‐FROG is implemented on a thin‐film lithium niobate (LN) platform, demonstrating its versatility and consistency in accurately characterizing waveguided femtosecond pulses, including information about chirp and self‐phase modulation. In contrast to traditional FROG techniques, T‐FROG represents a significant improvement as it provides temporal amplitude and phase profiles of ultrafast optical pulses directly inside photonic integrated circuits. The real‐time in situ characteristics and dynamics of optical pulses offered by T‐FROG show promise for their potential applications in the design, testing, and optimization of ultrafast photonic integrated circuits.

Dispersion tuning of nonlinear optical pulse dynamics in gas-filled hollow capillary fibers

Gas-filled hollow capillary fibers can be used for continuum generation and pulse compression. Here, the authors change the gas pressure inside hollow capillary fibers and investigate how ultrashort laser pulses propagating through the fibers respond to these changes. The use of short pulses and a long capillary fiber enables the authors to survey a much wider range of dynamics than previously observed.

Maximizing supercontinuum bandwidths in gas-filled hollow-core fibers using artificial neural networks

Machine learning has been used to accelerate studies in the dynamics of optical pulses. In this study, we use machine learning to investigate the optimal design of supercontinuum-generating hollow-core antiresonant fibers (HC-ARFs) pressurized and filled with methane. Artificial neural networks (ANNs) are trained to replace the numerical solvers, accelerate the simulation of fibers, and provide a more rapid fiber design procedure. We first use an analytical model to approximate the dispersion and loss of the methane-filled silica HC-ARF. This approximation is used by the generalized unidirectional pulse propagation equation solver to simulate the pulse propagation and generate training data for our ANNs by varying design parameters including the pump center wavelength, fiber hollow-core radius, fiber length, cladding strut thickness, and gas pressure. We evaluate the performance of different spectral-predicting ANN architectures and use the trained ANN along with a custom fiber performance function to search the full parameter space. Subsequently, the regions with design parameters with predicted high performance are identified, and these high-performance HC-ARF designs are further optimized for supercontinuum generation at target supercontinuum bandwidths. We also extend our effort to maximizing the total spectral energy outside of the input pump wavelength by integrating the ANN with a global optimization technique for the search of an optimal HC-ARF design.

Dynamics of optical pulses in fiber optics with stimulated Raman scattering effect

In this paper, we discuss the propagation of optical pulses in the nonlinear optical fibers. The generalized higher-order nonlinear Schrödinger equation (NLSE) is under consideration as a governing model. The studied model is composed of group-velocity dispersion, self-phase modulation, third-order dispersion, self-steepening and stimulated Raman scattering. Researchers have been studying a wide range of natural phenomena in depth, and nonlinear science has gradually become a part of people’s consciousness. We have extracted the optical pulses in different forms like bright, dark, singular and combined solitons by assistance of recently developed integration tool, namely the new extended direct algebraic method (NEDAM). Moreover, the solutions for the hyperbolic, periodic and trigonometric functions are retrieved. Using proper parameters in numerical simulations and physical explanations, it is possible to demonstrate the importance of the findings. It is proposed that the offered method can be utilized to support nonlinear dynamical models applicable to a wide variety of physical situations. We hope that a wide spectrum of engineering model professionals will find this study to be beneficial.

Dynamics of optical pulses in dual-core optical fibers modelled by decoupled nonlinear Schrodinger equation via GERF and NEDA techniques

Dynamics of optical pulses in dual-core optical fibers modelled by decoupled nonlinear Schrodinger equation via GERF and NEDA techniques

Dynamics of optical pulses in birefringent fibers without four-wave mixing effect via efficient computational techniques

In this manuscript, we discuss the dynamical behavior of Chen-Lee-Liu (CLL) equation in birefringent fibers which is modeled by two-component nonlinear Schrodinger equation (NLSE) without four-wave mixing effect. In optical fibers and other wave-guide mediums this system models the propagation of soliton flow using group velocity dispersion (GVD) and self-steeping coefficients. In the realms of maritime transport, motion, and energy, the dynamics of deep-sea waves is one of oceanography’s greatest challenges. A mathematical model of the dynamics of solitary waves in the deep ocean under a two-layer stratification yields the NLSE, and resultantly, the interaction between the two can be described by a coupled NLSE. Using two recently developed integration tools, namely the generalized exponential rational function method (GERFM) and the new extended direct algebraic method (NEDAM), the various optical pulses in the forms of bright, dark, combined, and complex solitons are extracted. Moreover, the hyperbolic, exponential, and trigonometric function solutions are recovered. In addition, a comparison is made between our results and those that are well-known, and the study concludes that the solutions we’ve reached are novel. By choosing appropriate parameter values for numerical simulation and physical explanations, the significance of the results is demonstrated. The results of this paper can enhance the nonlinear dynamical behavior of a given system and demonstrate the suitability of the methodology employed. This research, in our opinion, will be beneficial to a wide variety of engineering model specialists.

Manipulating photonic signals by a multipurpose quantum junction

We address a prototype integrated quantum circuit model system: a multifunctional quantum junction comprising three-level atomic nodes that couple two waveguides. We consider nodes with the $\mathrm{\ensuremath{\Lambda}}$ scheme of the allowed optical transitions, one of which is driven by an external classical electromagnetic field. We demonstrate that the latter field can be used to control the mode of the device operation: studying the dynamics of optical pulses, we show that the proposed integrated junction can operate as a controlled router or a switch, a 1/4 splitter, a delay line, or a storage node. The system offers also a possibility of intrinsic parallelism of quantum operations and can provide useful guidelines for making possible future quantum circuitry building blocks more scalable and integrated.

Bifurcation analysis and classification of all single traveling wave solution in fiber Bragg gratings with Radhakrishnan-Kundu-Lakshmanan equation

<abstract><p>The current work studies the bifurcation and the classification of single traveling wave solutions of the coupled version of Radhakrishnan-Kundu-Lakshmanan equation that usually describes the dynamics of optical pulses in fiber Bragg gratings, which is also described by a family of nonlinear Schrödinger equations with cubic nonlinear terms. The solutions of the hyperbolic functions, the rational functions, the trigonometric functions and the Jacobian functions are retrieved by using the complete discrimination system of polynomial. By selecting appropriate parameters, phase portraits, two-dimension graphics and three-dimension graphics of the obtained solutions are drawn.</p></abstract>

Оптические импульсы в фотонном кристалле на основе сверхрешетки в условиях оптического резонатора

Based on Maxwell's equations, an effective wave equation for the vector-potential of the electric field of the pulse is obtained. A computer simulation of the evolution of an optical pulse with a duration of several femtoseconds in a medium with a spatially variable refractive index based on a superlattice has been carried out. The system is placed in a cylindrical optical resonator. It has been established that optical pulses propagating in such a system retain their energy in a limited region of space. Numerical simulation of the dynamics of optical pulses was carried out at long times (up to 100 ps).

Dynamics of optical pulses in fiber optics

In this paper, we pay attention to the nonlinear dynamical behavior of ultra-short pulses in optical fiber. The new Hamiltonian amplitude equation is used as a governing model to analyze the pulses. We secure the ultra-short pulses in the forms of bright, dark, singular, combo and complex soliton solutions by the utilization of three of sound computational integration techniques that are protracted (or extended) Fan-sub equation method (PFSEM), the generalized exponential rational function method (GERFM), extended Sinh-Gordon equation expansion method (ShGEEM). Moreover, Jacobi’s elliptic, trigonometric, and hyperbolic functions solutions are also discussed as well as the constraint conditions of the achieved solutions are also presented. In addition, we discuss the different wave structures by the assistance of logarithmic transformation. The findings demonstrate that the examined equation theoretically contains a large number of soliton solution structures. By selecting appropriate criteria, the actual portrayal of certain obtained results is sorted out graphically in 3D and 2D profiles. The results suggest that the procedures used are concise, direct, and efficient, and that they can be applied to more complex phenomena. The resulting solutions are novel, intriguing, and potentially useful in understanding energy transit and diffusion processes in mathematical models of several disciplines of interest, including nonlinear optics. Our new results have been compared to these in the literature.

Predicting the dynamic process and model parameters of the vector optical solitons in birefringent fibers via the modified PINN

A modified physics-informed neural network is used to predict the dynamics of optical pulses including one-soliton, two-soliton, and rogue wave based on the coupled nonlinear Schrödinger equation in birefringent fibers. At the same time, the elastic collision process of the mixed bright-dark soliton is predicted. Compared the predicted results with the exact solution, the modified physics-informed neural network method is proven to be effective to solve the coupled nonlinear Schrödinger equation. Moreover, the dispersion coefficients and nonlinearity coefficients of the coupled nonlinear Schrödinger equation can be learned by modified physics-informed neural network. This provides a reference for us to use deep learning methods to study the dynamic characteristics of solitons in optical fibers.

3D few cycle optical pulses in carbon nanotube-based photonic crystal with allowance for mechanical stress

This paper constructs and numerically analyzes a theoretical model of three-dimensional few cycle optical pulse dynamics in semiconductor carbon nanotube-based spatially-modulated refractive index medium. It takes into account external deformation in terms of the gauge theory. It identifies the stable propagation of that kind of pulses in photonic crystal. The paper also reveals the dependence of pulse dynamics on photonic crystal characteristics (refractive index depth and modulation period in particular).

Optical-pulse dynamics under quasi- PT -symmetry

Optical-pulse dynamics under quasi- <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi mathvariant="script">P</mml:mi><mml:mi mathvariant="script">T</mml:mi></mml:mrow></mml:math> -symmetry

Design of Silica Multimode Optical Fibers with Extremely Enlarged Core Diameter for Laser-Based Multi-Gigabit Short-Range Optical Networks

This work presents an alternative fast and simple method for the design of a refractive index profile of silica multimode optical fibers (MMFs) with extremely enlarged core diameters of up to 100 µm for laser-based multi-gigabit short-range optical networks. We demonstrate some results of 100 µm core MMF graded index profile optimization performed by a proposed solution, which provides a selected mode staff differential mode delay (DMD) reduction over the “O”-band under particular launching conditions. Earlier on, a developed alternative model for a piecewise regular multimode fiber optic link operating in a few-mode regime for the computation of laser-excited optical pulse dynamics during its propagation over an irregular silica graded-index MMF with an extremely large core diameter, is utilized to estimate the potentiality of fiber optic links with the described MMFs. Here, we also present the comparison results of the simulation of 10GBase-LX optical signal transmission over 100 µm core MMFs with conventional and optimized graded-index refractive index profiles.

Spatiotemporal Control of Light Transmission through a Multimode Fiber with Strong Mode Coupling.

We experimentally generate and characterize eigenstates of the Wigner-Smith time-delay matrix, called principal modes, in a multimode fiber with strong mode coupling. The unique spectral and temporal properties of principal modes enable global control of temporal dynamics of optical pulses transmitted through the fiber, despite random mode mixing. Our analysis reveals that well-defined delay times of the eigenstates are formed by multipath interference, which can be effectively manipulated by spatial degrees of freedom of input wave fronts. This study is essential to controlling dynamics of wave scattering, paving the way for coherent control of pulse propagation through complex media.

Spatiotemporal dynamics of an optical pulse propagating in multimode hollow-core fibers filled with prealigned molecular gases

Spatiotemporal propagation dynamics of optical pulses in a multimode hollow-core fiber filled with prealigned molecular gases is numerically studied. Due to the use of accurate models, several interesting results are obtained, such as the periodic spatiotemporal evolution behavior, the formation of a stable donut-shaped beam profile, and the increasing of pulse energy during frequency upconversion. It is the use of hollow-core fibers that enables these behaviors to be observed. These observations enrich our understanding of optical pulse propagation dynamics and will benefit relevant technologies.

Dynamics of optical pulses in highly noninstantaneous Kerr media

The dynamics of optical pulses in noninstantaneous Kerr media are considered. It is found that the ``mass center'' of the localized profile exhibits an accelerated transversal (on the time axis) motion during propagation. In the highly noninstantaneous regime, especially, the motion can approximately be uniformly accelerated up to one dispersion length, which is also proportional to the ratio between the pulse power and the relaxation time of the media. The evolutions of the pulse width and chirp are also investigated. An interesting phenomenon is found: the nonlinearity-induced chirp in the highly noninstantaneous regime is the ``inverted image'' of the pulse shape. Based on the acceleration property of the transversal motion, the existence of soliton-like solutions in the noninstantaneous Kerr system is also discussed. It is found that the highly noninstantaneous Kerr system has no soliton-like solutions.

Optical pulse dynamics in active metamaterials with positive and negative refractive index

We study numerically the propagation of two-color light pulses through a metamaterial doped with active atoms such that the carrier frequencies of the pulses are in resonance with two atomic transitions in the &#x39B; configuration and that one color propagates in the regime of positive refraction and the other in the regime of negative refraction. In such a metamaterial, one resonant color of light propagates with positive and the other with negative group velocity. We investigate nonlinear interaction of these forward- and backward-propagating waves and find self-trapped waves, counterpropagating radiation waves, and hot spots of medium excitation.