Solitons and nonlinear dynamics in dual-core optical fibers (original) (raw)

Symmetric and asymmetric solitons in twin-core nonlinear optical fibers

1996

Static soliton states in twin-core nonlinear optical fibers are examined using an improved variational approximation: the soliton s width is an additional varying parameter, together with the ratio of the energies in, and the phase difference between, the two cores. For the symmetric coupler, results agree well with numerical ones; in particular, the bifurcation between symmetric and asymmetric solitons is shown to be slightly subcritical. For the asymmetric coupler, the control parameters are the difference between the cores' dispersion coefficients and the phase velocity mismatch. Soliton states in the asymmetric coupler show a strong and easily controlled bistability. The soliton exists for some energies even when one of the cores has normal dispersion.

Asymmetric solitons in mismatched dual-core optical fibers

Journal of the Optical Society of America B, 1997

We consider soliton solutions to equations describing a pair of tunnel-coupled nonlinear optical fibers with a phase-velocity mismatch between them. The analysis is based on the variational approximation, which is checked (with quite favorable results) against direct numerical solutions at selected values of the parameters. The results are presented in the form of curves demonstrating evolution of the energy in one of the soliton's components with increase of the mismatch, with the total energy of the soliton being fixed. Two bifurcations are found. One of them, which to our knowledge has not been observed in any form earlier, involves a termination, occurring at a finite value of the mismatch parameter, of the branch whose solitons have components of the opposite sign; this branch corresponds to the antisymmetric soliton in the model with no mismatch. The other, more important, bifurcation is perceived as the occurrence of a hysteresis-type behavior of another branch, whose solitons have the same signs of their components; this branch corresponds to both the symmetric and the asymmetric solitons in the model with no mismatch. The implications of this second bifurcation for the propagation of a subpicosecond soliton in a real-world dual-core fiber are also discussed. © 1997 Optical Society of America [S0740-3224 Kaup et al.

Saturation of the nonlinear refractive index for optical solitons in two-core fibers

Optik - International Journal for Light and Electron Optics, 2016

This article studies the dynamics of optical solitons in two-core fibers with saturation of the nonlinear refractive index describe by dual power law. The decoupled model is considered with group velocity dispersion, linear coupling coefficients and spatio-temporal dispersion. As the result bright, dark and two forms if singular optical 1-solitons are extracted using ansatz approach. Additionally, the constraint conditions for the existence of these solutions are also listed.

Spatiotemporal Vectorial Solitons in Nonlinear Ultrafast Dual-Core Fiber Lasers

The processes of soliton generation and interference focus on the complex nonlinear soliton dynamics resembling matter particles. In order to further understand the dynamic process of solitons from a multidimensional perspective, here we report the vectorial solitons nature under two-sets pulse splitting in a single cavity induced by dual-core fiber assisted ultrafast fiber lasers. Owing to the weakly coupled cores in symmetrical dual core fiber (SDCF), two pulse groups interaction are formed in a cavity. By using the dispersive Fourier transformation technique (DFT), it was found that the four-component polarized rotation vector solitons (PRVS) generate. Moreover, gradually increasing the power can obtain the locked soliton bound state in two core space, and the corresponding evolution is similar to that of non-degenerate bright solitons in Bose Einstein condensates (BEC). In addition, by properly controlling the soliton phase offset in SDCF, the soliton rain state of multi pulse e...

New soliton solutions in dual-core optical fibers

2017

In this paper, we study a certain class of equations that mode l the propagating in dual-core fibers. Linear stability anal ysis is applied to discuss the existence of some types of travelli ng wave solutions and to compute the wave speed. New doubly pe riodic solutions are obtained, and new bright and dark soliton solu tions are found.

Reversible ultrafast soliton switching in dual-core highly nonlinear optical fibers

Optics Letters, 2020

We experimentally investigate a nonlinear switching mechanism in a dual-core highly nonlinear optical fiber. We focus the input stream of femtosecond pulses on one core only, to identify transitions between inter-core oscillations, self-trapping in the cross core, and self-trapping of the pulse in the straight core. A model based on the system of coupled nonlinear Schrödinger equations provides surprisingly good agreement with the experimental findings.

Dynamics of solitons in coupled optical fibers

Optics Letters, 1989

The dynamics of soliton interaction in two tunnel-coupled optical fibers as a function of their phase difference T is analytically and numerically investigated. It is shown that if T = 0 or 7r, no energy redistribution occurs in the fibers, and the soliton pulses either form a coupled state (T = 7r) or repulse each other and separate during propagation (T = 0). Results of computer simulations under strong-coupling conditions are presented.

Stabilizing the Pereira-Stenflo Solitons in Nonlinear Optical Fibers

Physica Scripta, 2000

We study in detail stability of exact chirped solitary-pulse solutions in a model of a ¢ltered nonlinear optical ¢ber, in which stabilization of the pulses is achieved by means of an extra lossy core, parallel-coupled to the main one. We demonstrate that, in the model's three-dimensional parameter space, there is a vast region where the pulses are fully stable, for both signs of the group-velocity dispersion. These results open way to a stable transmission of optical solitons in the normal-dispersion region and, thus, to an essential expansion of the bandwidth o¡ered by the nonlinear optical ¢bers for telecommunications. In the cases when the pulses are unstable, we study the development of the instability, which may end up by either a blowup or decay to zero.