共查询到20条相似文献,搜索用时 15 毫秒
1.
Neshev DN Alexander TJ Ostrovskaya EA Kivshar YS Martin H Makasyuk I Chen Z 《Physical review letters》2004,92(12):123903
We report on the first experimental observation of discrete vortex solitons in two-dimensional optically induced photonic lattices. We demonstrate strong stabilization of an optical vortex by the lattice in a self-focusing nonlinear medium and study the generation of the discrete vortices from a broad class of singular beams. 相似文献
2.
We report the first experimental demonstration of ring-shaped photonic lattices by optical induction and the formation of discrete solitons in such radially symmetric lattices. The transition from discrete diffraction to single-channel guidance or nonlinear self-trapping of a probe beam is achieved by fine-tuning the lattice potential or the focusing nonlinearity. In addition to solitons trapped in the lattice center and in different lattice rings, we demonstrate controlled soliton rotation in the Bessel-like ring lattices. 相似文献
3.
Buljan H Cohen O Fleischer JW Schwartz T Segev M Musslimani ZH Efremidis NK Christodoulides DN 《Physical review letters》2004,92(22):223901
We predict the existence of random phase solitons in nonlinear periodic lattices. These solitons exist when the nonlinear response time is much longer than the characteristic time of random phase fluctuations. The intensity profiles, power spectra, and statistical (coherence) properties of these stationary waves conform to the periodicity of the lattice. The general phenomenon of such solitons is analyzed in the context of nonlinear photonic lattices. 相似文献
4.
利用变分法和数值计算方法研究了空间调制作用下Bessel型光晶格中玻色-爱因斯坦凝聚体系中孤立子的稳定性, 给出了存在随空间非周期变化的线性Bessel型光晶格和非线性光晶格(原子之间非线性相互作用的空间调制)时, 各种参数组合下涡旋和非涡旋孤立子的稳定性条件. 首先, 利用圆对称的高斯型试探波函数得出描述体系稳定性参数满足的Euler-Lagrange方程和变分法分析体系稳定性所需要的有效作用势能的表达式. 然后, 根据有效作用势能是否具有局域最小值判断体系是否具有稳定状态, 得出体系具有稳定状态时参数所满足的条件. 最后, 利用有限差分法求解Gross-Pitaevskii方程验证变分法结果的正确性, 所得结果和变分法结果一致.
关键词:
Bessel型光晶格
非线性光晶格
孤立子
稳定性 相似文献
5.
We address soliton transmission and reflection in nonlinear photonic lattices embedded into uniform Kerr nonlinear media. We show that by introducing disorder into the guiding lattice channels, one may achieve soliton transmission even under conditions where regular lattices reflect the input beam completely. In contrast, in the parameter range in which the lattice is almost transparent for incoming solitons, disorder may induce a significant reflection. 相似文献
6.
7.
Stable soliton complexes in two-dimensional photonic lattices 总被引:2,自引:0,他引:2
We show that two-dimensional photonic Kerr nonlinear lattices can support stable soliton complexes composed of several solitons packed together with appropriately engineered phases. This may open up new prospects for encoding pixellike images made of robust discrete or lattice solitons. 相似文献
8.
We introduce solitons supported by Bessel photonic lattices in cubic nonlinear media. We show that the cylindrical geometry of the lattice, with several concentric rings, affords unique soliton properties and dynamics. In particular, in addition to the lowest-order solitons trapped in the center of the lattice, we find soliton families trapped at different lattice rings. Such solitons can be set into controlled rotation inside each ring, thus featuring novel types of in-ring and inter-ring soliton interactions. 相似文献
9.
We address the existence,stability and propagation dynamics of solitons supported by large-scale defects surrounded by the harmonic photonic lattices imprinted in the defocusing saturable nonlinear medium.Several families of soliton solutions,including flat-topped,dipole-like,and multipole-like solitons,can be supported by the defected lattices with different heights of defects.The width of existence domain of solitons is determined solely by the saturable parameter.The existence domains of various types of solitons can be shifted by the variations of defect size,lattice depth and soliton order.Solitons in the model are stable in a wide parameter window,provided that the propagation constant exceeds a critical value,which is in sharp contrast to the case where the soliton trains is supported by periodic lattices imprinted in defocusing saturable nonlinear medium.We also find stable solitons in the semi-infinite gap which rarely occur in the defocusing media. 相似文献
10.
P. Rose T. Richter B. Terhalle J. Imbrock F. Kaiser C. Denz 《Applied physics. B, Lasers and optics》2007,89(4):521-526
We investigate the formation of fundamental discrete solitons and dipole-mode gap solitons in triangular photonic lattices
imprinted in photorefractive nonlinear media. These lattices are strongly affected by the photorefractive anisotropy, resulting
in orientation-dependent refractive index structures with reduced symmetry. It is demonstrated that two different orientations
of the lattice wave enable the formation of fundamental discrete solitons in the total internal reflection gap. Furthermore,
it is shown that one lattice orientation additionally supports dipole-mode solitons in the Bragg reflection gap. The experimental
results are corroborated by numerical simulations using the full anisotropic model.
PACS 42.65.Tg; 42.65.Wi; 42.70.Qs 相似文献
11.
We show that optically induced photonic lattices in a nonconventionally biased photorefractive crystal can support the formation of discrete and gap solitons owing to a mechanism that differs from the conventional screening effect. Both the bias direction and the lattice orientation can dramatically influence the nonlinear beam-propagation dynamics. We demonstrate a transition from self-focusing to -defocusing and from discrete to gap solitons solely by adjusting the optical-beam orientation. 相似文献
12.
We address the existence of vortex solitons supported by azimuthally modulated lattices and reveal how the global lattice discrete symmetry has fundamental implications on the possible topological charges of solitons. We set a general "charge rule" using group-theory techniques, which holds for all lattices belonging to a given symmetry group. Focusing on the case of Bessel lattices allows us to derive also an overall stability rule for the allowed vortex solitons. 相似文献
13.
Changming Huang 《Optics Communications》2011,284(18):4225-17188
We report on the dynamics of semi-localized nonlinear optical modes supported by an interface separating a uniform defocusing saturable medium and an imprinted semi-infinite photonic lattice. Out-of-phase and in-phase kink solitons composed by dark-soliton-like pedestals and oscillatory tails are found. Two branches of out-of-phase kink solitons exist in shallow lattices. Saturable nonlinearity enhances the pedestal height and renormalized energy flow of kink solitons evidently. While in-phase kink solitons are always unstable, out-of-phase kink solitons will be completely stable provided that lattice depth exceeds a critical value. Furthermore, stable kink solitons in the higher band gaps are also possible. Our results may give a helpful hint for understanding the dynamics of kink solitons with high pedestals in other fields. 相似文献
14.
Bingzhi Zhang 《Physics letters. A》2011,375(7):1110-1115
We investigate the formation of polarization vortex spatial optical solitons in optical lattice induced by a non-diffracting Bessel beam. The properties of these solitons in zeroth-order and first-order Bessel lattices with focusing and defocusing Kerr nonlinearity are discussed. It is found that these solitons have some analogies with phase vortex solitons carrying single positive or negative topological charge in these lattices. Besides, these polarization vortex solitons have complicated dynamical characteristic and can be stabilized in some parameter region. 相似文献
15.
Systematic results of collisions between discrete spatiotemporal dissipative Ginzburg-Landau solitons in two-dimensional photonic
lattices are reported. The generic outcomes are identified for (i) the collision of two identical solitons located in the
corner, at the edge, and in the center of the photonic lattice, and for (ii) the collision of two non-identical corner and
edge solitons located at different distances from the boundaries of the photonic lattice. Depending on the values of the kick
(collision momentum) and of the nonlinear (cubic) gain, the collision scenarios include soliton merging, creation of an extra
soliton, soliton bouncing, soliton spreading, and quasi-elastic (symmetric) interactions. 相似文献
16.
We study higher-order nonlinear modes in the form of vortex solitons and soliton clusters propagating in the waveguides created
in photonic crystal fibers made of a material with the focusing Kerr nonlinearity. We find numerically different families
of such nonlinear modes with a nontrivial topology and study their bifurcations. We also study the soliton stability to propagation.
We demonstrate that waveguides in photonic crystal fibers may support a variety of soliton clusters with the symmetries that
may differ from the lattice symmetry. We also discuss briefly the case of a dual-core coupler created by two neighboring cores
in a photonic crystal fiber and find numerically the profiles of symmetric and asymmetric nonlinear modes. 相似文献
17.
Terhalle B Richter T Desyatnikov AS Neshev DN Krolikowski W Kaiser F Denz C Kivshar YS 《Physical review letters》2008,101(1):013903
We report on the first observation of topologically stable spatially localized multivortex solitons generated in optically induced hexagonal photonic lattices. We demonstrate that topological stabilization of such nonlinear localized states can be achieved through self-trapping of truncated two-dimensional Bloch waves and confirm our experimental results by numerical simulations of the beam propagation in weakly deformed lattice potentials in anisotropic photorefractive media. 相似文献
18.
Topological edge solitons represent a significant research topic in the nonlinear topological photonics. They maintain their profiles during propagation, due to the joint action of lattice potential and nonlinearity, and at the same time are immune to defects or disorders, thanks to the topological protection. In the past few years topological edge solitons were reported in systems composed of helical waveguide arrays, in which the time-reversal symmetry is effectively broken. Very recently, topological valley Hall edge solitons have been demonstrated in straight waveguide arrays with the time-reversal symmetry preserved. However, these were scalar solitary structures. Here, for the first time, we report vector valley Hall edge solitons in straight waveguide arrays arranged according to the photonic lattice with innate type-II Dirac cones, which is different from the traditional photonic lattices with type-I Dirac cones such as honeycomb lattice. This comes about because the valley Hall edge state can possess both negative and positive dispersions, which allows the mixing of two different edge states into a vector soliton. Our results not only provide a novel avenue for manipulating topological edge states in the nonlinear regime, but also enlighten relevant research based on the lattices with type-II Dirac cones. 相似文献
19.
We study self-localized second-band vortex states in two-dimensional photonic lattices and find stable ring solitons whose phase forms an array of counterrotating vortices. We also identify composite solitons in which a second-band vortex is jointly trapped with a mode arising from the first band and study their stability. When such a composite entity is unstable, it disintegrates while exchanging angular momentum between its constituents, eventually stabilizing into another form of composite soliton. 相似文献
20.
We discuss the formation of guided modes localized at the interface separating two different periodic photonic lattices. Employing the effective discrete model, we analyze linear and nonlinear interface modes and also predict the existence of stable interface solitons including the hybrid staggered/unstaggered lattice solitons with the tails belonging to spectral gaps of different types. 相似文献