Nonlocal Solitons Research Articles

Nonlocal solitons in the parametrically driven nonlinear Schrödinger equation: Stability analysis

We study analytically and numerically the linear stability of weakly nonlocal solitons in the parametrically driven nonlinear Schrödinger equation. Two exact solutions are derived in an implicit form. We show analytically that despite the well-known stabilizing properties of nonlocality one of the solitons remains unstable even in the nonlocal case for any values of the dissipation, the damping, and the degree of nonlocality. The second soliton, as compared to its local counterpart, attains wider stable regions in the space of the parameters of the system.

Large phase shift of spatial solitons in lead glass

A large phase shift of the strongly nonlocal spatial optical soliton (SNSOS) was predicted by Guo et al. [Phys. Rev. E69, 016602 (2004)]. We investigate the phase shift of the SNSOS in lead glass. It is found that the phase shift rate along the propagating direction of such a soliton is one order larger than that of the local soliton. The theory agrees quantitatively with the experiment on the dependence of the phase shift on the degree of nonlocality. We realize a π-phase shift by changing the optical power by about 10 mW around the critical soliton power, which agrees qualitatively with our theoretical result.

Frustrated quantum phase diffusion and increased coherence of solitons due to nonlocality

We investigate the quantum properties of solitons with nonlocal self-interaction. We find significant changes when compared to the local interaction. Quantum phase diffusion of nonlocal solitons is always reduced with respect to the local interaction and vanishes in the strongly nonlocal limit. Thus, coherence is increased in the nonlocal case. Furthermore, we compare the intrinsic quantum wave packet spreading to the recently discussed classical Gordon-Haus effect for nonlocal solitons [V. Folli and C. Conti, Phys. Rev. Lett. 104, 193901 (2010)].

Relation between surface solitons and bulk solitons in nonlocal nonlinear media

We find that a surface soliton in nonlocal nonlinear media can be regarded as a half of a bulk soliton with an antisymmetric amplitude distribution. The analytical solutions for surface solitons and breathers in strongly nonlocal media are obtained, and the critical power and breather period are gotten analytically and confirmed by numerical simulations. In addition, the oscillating propagation of nonlocal surface solitons launched away from the stationary position is considered as interaction between the soliton and its out-of-phase image beam. Its trajectory and oscillating period obtained by our model are in good agreement with the numerical simulations.

Three-dimensional short-range interactions of strongly nonlocal optical spatial solitons

Basing on the accurate Gaussian analytical solution of a pair of (1+2)D optical spatial solitons with symmetrical oblique incidence,we investigated the short-range interactions in the strongly nonlocal nonlinear media.Two solitons in close proximity can be intertraped via the strong nonlocality ,and propagate together in a stable spiral and the trajectory of mass center of solitons will deflect because of the phase difference and the ratio of the power of two solitons under the condition of momentum conservation. It is possible to find its application in planar all-optical interconnection in bulk media.We analyszed the evolution of the Poynting vector as they propagate through the strongly nonlocal media.

Strongly nonlocal spatial soliton propagation in lead glass

The soliton propagations in lead glass separately with circle and rectangle boundaries are theoretically and experimentally investigated. Based on the image beam method the soliton propagation in lead glass is comprised of two independent processes: the soliton forming and the soliton steering as a whole. The soliton-forming process is boundary independent, which is caused by the source beam itself induced refractive index distribution. The force which leads to the soliton steering essentially comes from the boundary effect and is equal to the force between the soliton beam and all of the image beams. The numbers of the images are one and infinite respectively for the boundaries of circle and rectangle. This results in a different steering force with a different boundary. The closed-form solutions of the soliton critical power and the steering trajectories are in good agreement with the experimental results.

Theoretical study on large phase shift of strongly nonlocal spatial optical soliton and its application design

Compared with local spatial optical solitons and linearly propagating beams, nonlocal spatial optical solitons each have a large phase shift during their propagation. However no one has paid attention to the intrinsic characteristics since the theoretical proof by Guo. We develop the phenomenological theory of Guo and find that there appears π phase shift with the change of the soliton power or the power of the pump soliton. Based on the conclusion that the modulation of the pump-soliton power on the signal-soliton phase has a high sensitivity, we propose a feasible scheme of realizing the optical switch.

非局域空间光孤子临界功率的确定

非局域空间光孤子临界功率的确定

Highly Noninstantaneous Solitons in Liquid-Core Photonic Crystal Fibers

The nonlinear propagation of pulses in liquid-filled photonic crystal fibers is considered. Because of the slow reorientational nonlinearity of some molecular liquids, the nonlinear modes propagating inside such structures can be approximated, for pulse durations much shorter than the molecular relaxation time, by temporally highly nonlocal solitons, analytical solutions of a linear Schrödinger equation. The physical relevance of these novel solitons is discussed.

Three-dimensional interaction of strongly nonlocal optical spatial solitons

Abstract With a 1 + 2D strongly nonlocal model, we present an analytical solution of the interaction of two unaligned optical solitons. It is shown that transferring of the two beams in a stable spiraling is possible for a large range of parameters. The spiraling structure dose not depend on the initial relative phase. The projection of the two beams centers in the transverse coordinate plane lies in the same ellipse. The two periods such as the spiraling period and the energy exchange period are expressed firstly.

Enhancement of third-harmonic generation in nonlocal spatial solitons

We report on the observation of Type I third-harmonic generation induced by a train of femtosecond laser pulses in nematic liquid crystals. We find that as the average power of the train is increased, the frequency conversion process is enhanced as a consequence of the tight confinement of the pulses into a nonlocal spatial soliton.

Spectral tunneling of lattice nonlocal solitons

We address spectral tunneling of walking spatial solitons in photorefractive media with nonlocal diffusion of the nonlinear response and an imprinted shallow optical lattice. In contrast to materials with local nonlinearities, where solitons travelling across the lattice close to the Bragg angle suffer large radiative losses, in photorefractive media with diffusion nonlinearity resulting in self-bending solitons survive when their propagation angle approaches and even exceeds the Bragg angle. In the spatial frequency domain this effect can be considered as tunneling through the band of spatial frequencies centered around the Bragg frequency where the spatial group velocity dispersion is positive.

Analytical theory of dark nonlocal solitons

We investigate properties of dark solitons in nonlocal materials with an arbitrary degree of nonlocality. We employ the variational technique and describe dark solitons, for the first time to our knowledge, in the whole range of degree of nonlocality.

The propagation of dipole solitons in highly nonlocal medium

This paper studies the propagation of dipole solitons in highly nonlocal medium by using the variational method. It finds that the dipole solitons will be stable when the input power obeys a restrict value. When the incident power does not satisfy the stable conditions, the nonlocal accessible dipole solitons will undergo linear harmonic oscillation. It shows such evolution behaviours in detail.

Space-time bullet trains via modulation instability and nonlocal solitons

We introduce the generation of dense trains of light-bullets in nonlocal nonlinear dielectrics. We exploit stable spatio-temporal self-trapped optical packets stemming from the interplay between local electronic and nonlocal reorientational nonlinearities, considering a seeded temporal modulation instability by specifically referring to nematic liquid crystals.

Applications of spectral renormalization method to the research of nonlocal optical spatial soliton

We use spectral renormalization method to solve the nonlocal nonlinear Schrdinger equation, which gives accurate waveform of nonlocal optical spatial soliton. The relation between critical power and critical beamwidth is acquired in different nonlocal conditions. We discovered that optical spatial soliton exists stably in any nonlocal degree. Comparing analytic solution with numerical solution for different response functions, we find that they are consistent only under strong nonlocal and weak nonlocal conditions. The effective range of analytic solution is also given.

Steering of nonlocal optical soliton in rectangular boundary lead glass

We studied the steering of the nonlocal spatical optical soliton in thermal optical nonlinear lead glass theoretically and experimentally. By employing the conformal mapping method, the response function of the lead glass was obtained, and the influence of the boundary on the response function is discussed. Then we obtained the trajectory for the off-center soliton and the output displacement equation when the point of incidence is varied. We also observed experimentally the phenomenon of steering of the optical soliton in lead glass whose boundary shape is rectangular. The theoretical results are in good agreement with the experimental observations.

Two-dimensional Kummer-Gaussian soliton clusters in strongly nonlocal nonlinear media

We solve the two-dimensional strongly nonlocal nonlinear Schrdinger equation in polar coordinates. An exact analytical solution of self-similar waves, namely Kummer-Gaussian soliton clusters, is obtained. Numerical simulations confirm the validity of the analytical solutions. It is shown that the nonlocal optical spacial solitons have large phase shift.

Power controlled short-range interactions between strongly nonlocal spatial soliton

We investigate the power controlled short-range interactions between spacial optical solitons in the strongly nonlocal nonlinear media. For the short-range interactions, the trajectory of mass center of solitons will deflect because of the phase difference under the condition of momentum conservation. We verify by experiment that the degree of deflection depends on the ratio of the power of two solitons, and the case of equal power corresponds to the maximum deflection. Using the characteristics of power control on the interaction between solitons, we measure the photic-induced response time of nematic liquid crystals, and find that it is much shorter than the bias-voltage-induced response time.

Incoherently coupled vector dipole soliton pairs in nonlocal media

We investigate the incoherently and strongly coupled Manakov vector dipole soliton pairs in nonlocal nonlinear media. We use variational approach, to describe analytical properties of these solutions in a strongly nonlocal regime. We show that the presence of fundamental component improve stability of the dipole nonlocal soliton. In the limit of highly nonlocal nonlinearity, the evolution behaviors of the vector solitons is determined by their total power.