Propagation In Optical Fibers Research Articles

Engineering the high-frequency components of coherent supercontinuum generation in hybrid optical fibers with yttrium aluminum garnet core

Coherent supercontinuum (SC) generation in optical fibers has spurred extensive research interest and found many applications. Here, we report a hybrid optical crystal fiber with an yttrium aluminum garnet (YAG) core. The optimized fiber features broad and flat near-zero normal dispersion and three wavelengths where the dispersion slope is zero. Through numerical modeling, we in detail investigate the influence of the pump wavelengths near the three wavelengths on the spectral broadening. The spectral broadening shows asymmetric towards the high-frequency region. The longer the pump wavelength, the more is the short wavelength components of the generated SC. Thus, the high-frequency components of the SC spectra can be engineered in the fiber. Interestingly, the occurrence of optical wave breaking (OWB) in the low-frequency region is prior to that in the high-frequency region when the pump wavelength is at 1660 nm. The broadest spectrum could be obtained when the pump wavelength is near the middle wavelength where the dispersion slope is zero. The result provides a new strategy for fiber design and broadband SC generation, which is different from the viewpoint that the broadest spectrum can be obtained when the pump wavelength near the local maximum dispersion. Combined with high nonlinearity and flat dispersion, the hybrid fiber allows octave-spanning SC generation with the pump power low to 1 kW at 1100 nm. This provides the potentials for high-power, broadband, and coherent SC generation at 1064 nm where the dispersion slope is near zero.

The soliton analysis for optical fibers models

Optical fibers have a major role in the industry and daily life. To simulate the pulse propagation in optical fibers, numerous models are seen in the literature. In this work, the Kundu-Mukherjee-Naskar (KMN) model and the anti-cubic Schrödinger equation are considered. To solve these models, ansatz-based methods are considered and also, the problem about the determination of transformation is replied so that it is not clear in the literature. The results of the proposed models will play a key role in applications in nonlinear optics, fluid dynamics, quantum mechanics and various other branches of science.

Optical solitons and single traveling wave solutions of Biswas-Arshed equation in birefringent fibers with the beta-time derivative

<abstract><p>This article describes the construction of optical solitons and single traveling wave solutions of Biswas-Arshed equation with the beta time derivative. By using the polynomial complete discriminant system method, a series of traveling wave solutions are constructed, including the rational function solutions, Jacobian elliptic function solutions, hyperbolic function solutions, trigonometric function solutions and inverse trigonometric function solutions. The conclusions of this paper comprise some new and different solutions that cannot be found in existing literature. Using the mathematic software Maple, the 3D and 2D graphs of the obtained traveling wave solutions were also developed. It is worth noting that these traveling wave solutions may motivate us to explore new phenomena which may be appear in optical fiber propagation theory.</p></abstract>

Abundant optical solitons of the (2 + 1)-dimensional Biswas-Milovice equation arising in optical fiber

In this study, we aim to investigate the (2 + 1)-dimensional Biswas-Milovice equation that describes the pulse propagation in optical fiber. With the help of the Exp-function based method and He’s frequency formulation, eleven sets of the optical solitons such as bright soliton, dark soliton, bright-dark soliton, kinky bright-dark soliton and periodic soliton solutions are obtained. The behaviors of the results are presented through the 3-D plot and 2-D curve. The findings of this paper are expected to opened up new horizons for the study of the soliton theory in optics.

Specialty optical fiber modeling, fabrication, and characterization: introduction

In this introduction, we provide an overview of the papers that were accepted for publication in the feature issue on specialty optical fiber modeling, fabrication, and characterization. A total of 22 papers were published in JOSA B. This feature issue presents cutting-edge research on specialty optical fibers and highlights recent developments in a new generation of optical fibers.

A generalized Kundu--Eckhaus equation with an extra-dispersion: pulses configuration

Raman effect is due to self-phase modulation (SPM), which is embedded in Kundu--Eckhaus equation KEE. Here, the objective of this work is to present a generalized KEE by accounting for an extra dispersion which may be induced by Raman scattering. Also, attention is focused to study the effects of the extra dispersion.Which are investigated via obtaining the exact solutions of the new model equation. These solutions are found by the unified method and by introducing a new transformation that ispects soliton- periodic wave collision. We aim to show that a variety of shapes of optical pulses OPs propagation in optical fibers occurs. Waves of multiple geometric structures are observed. Among these waves, hybrid lumps, soliton, cascade, complex chirped, hybrid w-shaped, rhombus (diamond) waves and soliton self phase modulation.The characteristics of the pulses; intensity, frequency, wavelength, polarization, and spectral content are identified. The results found here are of great interest in experimenting the effects of the induced dispersion on pulses configurations. Further, the colliding dynamics are inspected and as it is observed that no rogue or sharp waves formation hold, so the collision is elastic.

Abundant exact soliton solutions to the Fokas system

In the current work, we consider the Fokas system that describes the nonlinear pulse propagation in monomode optical fibers. By employing the Exp-function method, we succeed in constructing six families(eleven sets) of the exact soliton solutions. And the behaviors of the real, imaginary and absolute parts of the solutions are described through the 3-D contours. It reveals that the Exp-function method is an effective method to construct abundant exact solutions for the partial differential equations arising in optics.

Soliton interaction of a generalized nonlinear Schrödinger equation in an optical fiber

Under investigation in this work is a generalized nonlinear Schrödinger (NLS) equation with high-order dispersion and quintic nonlinear terms, which can describe a subpicosecond pulse propagation in optical fibers. By developing Hirota method, the bilinear form and analytical one- and two-soliton solutions are derived. Based on the analytical solutions, we give the corresponding soliton patterns to analyse dynamics of the pulse solitons. It shows that high order dispersion term may change the periodicity of propagation. The interaction of two pulse solitons is an elastic collision. By choosing suitable parameter values, we can obtain the two parallel solitons. It can be applied to improve transmission quality and capacity of information in optical fiber.

Dynamics of optical solitons in higher-order Sasa–Satsuma equation

Higher order and multidimensional generalizations of the nonlinear Schrödinger equation are useful in a variety of applications. A generalized (3+1)-dimensional nonlinear Sasa–Satsuma equation is studied via the improved generalized Riccati equation mapping method and its Bäcklund transformation and the extended hyperbolic function method. This nonlinear model can be use to describe the physical processes of wave propagation in optical fibers. We explicitly retrieved varieties of optical solitons like bright, dark, singular, combined bright–dark and combined singular-bright to this multidimensional generalized nonlinear model. Other solutions, such as periodic, rational, and exponential solutions of different structures, are also produced as a result of the evolution of this improved technique. Furthermore, the graphs in two and three dimensions are provided to visualize the structure of the solutions acquired by choosing certain parameter values.

Analytical simulations of the Fokas system; extension (2 + 1)-dimensional nonlinear Schrödinger equation

This paper studies novel analytical solutions of the extended [Formula: see text]-dimensional nonlinear Schrödinger (NLS) equation which is also known with [Formula: see text]-dimensional complex Fokas ([Formula: see text]D–CF) system. Fokas derived this system in 1994 by using the inverse spectral method. This model is considered as an icon model for nonlinear pulse propagation in monomode optical fibers. Many novel computational solutions are constructed through two recent analytical schemes (Ansatz and Projective Riccati expansion (PRE) methods). These solutions are represented through sketches in 2D, 3D, and contour plots to demonstrate the dynamical behavior of pulse propagation in breather, rogue, periodic, lump, and solitary characteristics. The stability property of the obtained solutions is examined based on the Hamiltonian system’s properties. The obtained solutions are checked by putting them back into the original equation through Mathematica 12 software.

Light Localization and Principal Mode Propagation in Optical Fibers

The capacity of optical fiber communications has grown exponentially since its implementation decades ago. Optical fiber amplifiers, wavelength division multiplexing, and coherent communications have all enabled discontinuous growth. Space division multiplexing is proposed as the next discontinuity. Here tens of modes rather than a single mode are utilized in the transmission. Random scattering due to index fluctuations within the optical fiber cause coupling among the modal channels thereby degrading signal transmission. Principal mode transmission overcomes this limitation. Here a set of modes arrive localized at the fiber output unscattered. We review this methodology as it relates to optical communication capacity, but also as it relates to light localization. We also review the characterization of these modes both theoretically and experimentally.

Study of the parametric effects on soliton propagation in optical fibers through two analytical methods

The dual-core optical fiber has significant applications in optical electronics for long-wave propagation, especially in telecommunication fibers. The aim of this article is to study the parametric effects on solitary wave propagation and characteristic aspects of long-wave traveling through optical fibers by establishing some standard and wide-spectrum solutions via the improved Bernoulli sub-equation function (IBSEF) method and the new auxiliary equation (NAE) approach. The investigated solitary wave solutions are ascertained as an integration of hyperbolic, exponential, rational and trigonometric functions and can be extensively applicable in optics. The physical significance of the solutions attained is illustrated for the definite values of the included parameters through depicting the 3D profiles. The solitons profile represents different types of waves associated with the free parameters which are related to wave number and velocity. It turns out that the solutions obtained through both the methods are potential and can be used to interpret signals in telecommunication fibers and other works which can reduce casualties that ensue in essence.

Abstracts from the World Federation for Laser Dentistry—Asia Pacific Division Virtual Conference July 16–17, 2021

Abstracts from the World Federation for Laser Dentistry—Asia Pacific Division Virtual Conference July 16–17, 2021

Hollow-core mode propagation in an isomeric nested anti-resonant fiber.

We present a modified fiber model based on the nested hollow core anti-resonant fiber that enables the stable transmission of the orbital-angular-momentum mode HE21. By replacing a pair of nested anti-resonant tubes in the horizontal axis with resonant tubes, the coupling between core mode and cladding mode has been increased. Therefore, the relative strength of fundamental mode HE11 and the first higher mode HE21 has been modified. The numerical simulation results indicate that the loss ratio of the lowest loss HE11 to HE21 can be optimized to more than 187, while the HE21 still maintains a low confinement loss as 0.0027 dB/m. Our research has brought about a solution of low loss hollow core mode propagation in optical fiber. Those properties will make this fiber an ideal medium for blue-detuned atomic guidance.

A shower of mid-infrared Raman solitons at designed wavelength of ∼3 μm from a tapered fluorotellurite fiber

Optical temporal soliton generation in optical fibers and resonators has achieved great breakthroughs and found significant applications in many fields. Despite recent advances on optical soliton generation in optical fibers, it remains challenging to realize a shower of Raman solitons at a certain wavelength in optical fibers, i.e. put all the generated Raman solitons at a same wavelength on demand. Here we propose and experimentally demonstrate a shower of mid-infrared Raman solitons at designed wavelength of 3 μm from a tapered fluorotellurite fiber pumped by a 1960 nm picosecond fiber laser. Tapered fluorotellurite fibers have an untapered region length of ∼49 cm and a tapered transition region length of ∼1 cm. The fiber segment at the end of the tapered region has a 2nd zero-dispersion wavelength of ∼3 μm. Firstly, multiple Raman solitons with different wavelengths are generated in the untapered region pumped by the 1960 nm picosecond laser. Then, as Raman solitons propagate into the tapered region, the redshift of all the generated Raman solitons with different wavelengths are accelerated due to the dramatic increase of the nonlinear coefficient. Finally, as Raman solitons move out from the tapered region, all the accelerated Raman solitons are stopped around 3 μm owing to the occurrence of soliton self-frequency shift cancellation, causing the generation of a shower of mid-infrared Raman solitons around 3 μm. This phenomenon may find applications in super-efficient nonlinear light generation and signal processing.

Dynamical properties of the generalized model for description of propagation pulses in optical fiber with arbitrary refractive index

A partial differential equation for description of pulse propagation in optical fiber with arbitrary refractive index is considered. Using Melnikov method, an analytical condition for the existence of horseshoe chaos is obtained for the traveling wave reduction of the investigated equation. A way to control chaos in the dynamical system is proposed. An analytical prediction is tested numerically by plotting basins of attraction.

Optical solitons of the [formula omitted]-dimensional Biswas–Milovic equation using modified extended [formula omitted]-function method

In this paper, we study the novel exact solutions of the (2+1)-dimensional Biswas–Milovic equation for the description of pulse propagation in optical fiber. We successfully constructed some important solutions, such as dark, singular, combined dark-singular soliton, singular periodic wave and rational function solutions, have been analytically obtained using the extended tanh method. These solutions might play an important role in the engineering and physics fields. It is shown that the considered method provide a straightforward and powerful mathematical tool for solving problems in nonlinear optic and other physical phenomena.

Analytical solutions for the coupled Hirota equations in the firebringent fiber

Under investigation in this paper are the coupled Hirota (CH) equations, which describe the collision of two waves in the deep ocean and the propagation of the ultrashort optical pulses in a birefringent fiber. Based on the bilinear method, multi-soliton solutions for the CH equations are given. From the perspective of analysis, the interaction dynamics of solitons are obtained. The head-on and overtaking interactions of two/three solitons are analyzed. The elastic and inelastic interactions of two/three solitons are presented. The soliton velocity can be controlled by adjusting the physical parameters ϕj,(j=1,2,…N) and ϵ. The energy exchange occurs between the variables u and v before and after the collision. The local interference of two/three solitons is observed. The closer to the center of the interaction, the more significant the interference. The real and imaginary parts of the parameters ϕj,(j=1,2,…N) have the effects on the numbers of peaks and holes in the collisions. The structure of four eyes and one peak is observed during the two-soliton interaction. The three-soliton interactions are given with two peaks and local interference. It is hoped that the results of this study can provide some reference for the wave interaction in deep ocean, pulse propagation in optical fiber, financial option pricing, valuation of intangible assets in sports and so on.

Interactions of Soliton in Weakly Nonlocal Nonlinear Media

Solitary waves or solitons is a nonlinear phenomenon which has been studied intensively due to its application in solid-state matter such as Bose-Einstein condensates state, plasma physics, optical fibers and nematic liquid crystal. In particular, the study of nonlinear phenomena occurs in the structure of waves gained interest of scholars since their discovery by John Russell in 1844. The Nonlinear Schrödinger Equation (NLSE) is the theoretical framework for the investigation of nonlinear pulse propagation in optical fibers. Nonlocality can be found in an underlying transport mechanisms or long-range forces like electrostatic interactions in liquid crystals and many-body interactions with matter waves in Bose-Einstein condensate or plasma waves. The length of optical beam width and length of response function are used to classify nonlocality in optical materials. The nonlocality can be categorized as weak nonlocal if the width of the optical beam broader than the length of response function and if the width of the optical beam is narrower than the length of response function, it is considered as highly nonlocal. This work investigates the interactions of solitons in a weakly nonlocal Cubic NLSE with Gaussian external potential. The variational approximation (VA) method was employed to solve non integrable NLSE to ordinary differential equation (ODE). The soliton parameters and the computational program are used to simulate the propagation of the soliton width and its center-of-mass position. In the presence of Gaussian external potential, the soliton may be transmitted, reflected or trapped based on the critical velocity and potential strength. Direct numerical simulation of Cubic NLSE is programmed to verify the results of approximation method. Good agreement is achieved between the direct numerical solution and VA method results.

Visible light flashes induced by pulsed stimulated Brillouin scattering in narrow-linewidth, high-power, near-IR fiber lasers

We report an interesting observation of visible light flashes indicating pulsing events in Near Infrared fiber laser systems. Using a narrow-linewidth, continuous-wave (CW) fiber laser operating at 1064 nm, we observed visible flashes composed of faint, red, orange, yellow and green colors. Concurrently with the visible flashes, the spectra in the backward direction showed different Raman Stokes orders of 1064 nm for a silica medium. We attribute this form of visible light generation to Cherenkov-type phase-matched harmonic generation in optical fibers enabled by high-peak-power parasitic pulses. These pulses are attributed to the onset of stimulated Brillouin scattering. The harmonics of different Raman Stokes orders of the pulses are responsible for the different visible colors observed. This effect is potentially observable in any laser system with a high optical power with a CW, quasi-CW or pulsed form.