Solitons In Self-defocusing Media Research Articles

Propagation Characteristics of Coupled Dark Solitons in Self-defocusing Media

Propagation Characteristics of Coupled Dark Solitons in Self-defocusing Media

Incoherently coupled two-color vector dark solitons in self-defocusing media.

We investigate the stability of incoherently coupled two-color vector dark and grey solitons in a nonlinear self-defocusing media. We employ the variational technique to derive approximate solutions of the two-color vector dark solitons. The relations between the soliton parameters and the representation of the transverse velocities of the vector solitons are analytically obtained. We also demonstrate numerically the propagation dynamics of the two-color vector solitons, which shows that the two-color vector dark and grey solitons with different wavelengths are always unstable.

Two dimensional gap solitons in self-defocusing media with PT-symmetric superlattice

A theory is presented to study the existence and stability properties of fundamental solitons, multi-peaked gap solitons and vortex solitons in self-defocusing media with PT-symmetric superlattice. In the first gap of the superlattice potential, fundamental, dipole, and in-phase quadruple solitons can exist stably within a wide parameter region, while in-phase two-peaked solitons, out-of-phase quadruple solitons and vortex solitons are always unstable. Compared with simple-lattice solitons in similar potentials, the gap solitons in superlattice have a wider stable range than those in simple-lattice.

Algebraic bright and vortex solitons in self-defocusing media with spatially inhomogeneous nonlinearity

We investigate algebraic bright and vortex solitons in self-defocusing (SDF) media with a type of spatially inhomogeneous nonlinearity. For a specific choice of the nonlinearity parameters, certain exact analytical solutions for algebraic bright and vortex solitons have been constructed. By applying the linear stability analysis, the stability regions of these algebraic solitons are obtained numerically. In addition, we show analytically that a homogeneous SDF nonlinearity superposed by a localized self-focusing nonlinearity can support exact algebraic bright solitons under certain conditions.

Three-Dimensional Vortex Solitons in Self-Defocusing Media

We demonstrate that families of vortex solitons are possible in a bidispersive three-dimensional nonlinear Schrödinger equation. These solutions can be considered as extensions of two-dimensional dark vortex solitons which, along the third dimension, remain localized due to the interplay between dispersion and nonlinearity. Such vortex solitons can be observed in optical media with normal dispersion, normal diffraction, and defocusing nonlinearity.

DYNAMIC CONVERSION FROM SELF-DEFOCUSING TO EQUIVALENT “SELF-FOCUSING” IN PHOTOVOLTAIC LiNbO3:Fe CRYSTALS

We experimentally studied the dynamic behavior of conversion from self-defocusing to equivalent “self-focusing” in LiNbO3:Fe crystal under certain experiment conditions. Its physical mechanism is the consequence of both the double-Phase conjugate Fabry-Perot interference cavity and photorefractive effect. It is possible to form bright spatial solitons in self-defocusing medium by the effect of dynamic conversion.

Dynamical behaviour of unbounded spatial solitons in self-defocusing media with small χ(5) self-focusing nonlinearity

A numerical study is made on dynamics of unbounded bright/dark spatial soliton (UBSS/DSS) in self-defocusing Kerr media with small χ (5) self-focusing nonlinearity. Induced by the non-soliton part in the initial condition, soliton scattering process is followed by uneven energy redistribution between the scattered wavepackets with the additional radiation taking part in. Enhanced by the χ (5) self-focusing effect with modification of the cubic defocusing nonlinearity, the resultant propagation of the coupled UBSS/DSS channels presents a striking contrast in brightness/blackness. Stable propagation of such soliton pair requires exacting physical conditions composed of appropriate ratio of cubic-quintic nonlinearity and initial repulsive force of sufficient strength matched with fitting input light power.

Oblique interactions of dark spatial solitons in self-defocusing media

The oblique interaction of two dark spatial soliton stripes propagating in a uniform self-defocusing Kerr medium is considered. Both positive and negative colliding phase shifts are possible, depending on the blackness of the dark solitons and the geometry of the interaction. The critical angle between the propagating directions of two solitons at which no phase shift occurs as a result of the interaction is 120°.