共查询到20条相似文献,搜索用时 109 毫秒
1.
强非局域空间光孤子是指满足强非局域条件的空间孤子.在Snyder和Mitchell工作的基础上,获得了不共面对称斜入射(1+2)维强非局域空间光孤子对相互作用问题的精确解析解.结果表明,光束初始中心距离在大范围尺度内变化时,双孤子的演化都能形成类似DNA结构的稳定缠绕,这种稳定缠绕的结构与双孤子的初始相位差无关;光束中心在横截面上的投影轨迹一般是一个斜椭圆,通过改变两光束的初始中心距离和倾斜度可以控制该椭圆轨迹的变化.指出了利用(1+2)维强非局域空间光孤子的相互作用特性实现平面全光开关和全光互联的潜在可能性.
关键词:
(1+2)维非局域非线性介质
空间光孤子的相互作用
全光开关
全光互联 相似文献
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利用(1+1)维Snyder-Mitchell模型讨论了由强非局域介质构成的平面介质波导中同频率和同极化的双光束和三光束同向共同传输的相互作用过程,得到了任意斜入射双光束和三光束相互作用的精确解析解.强非局域空间光孤子的相互作用过程是其特殊情况.基于强非局域空间光孤子的相互作用原理, 提出了实现光子开关、光子“同”(XNOR)和“或非”(NOR)逻辑的新理论方案,并讨论这些基本光子信息处理器件的优化设计问题.
关键词:
强非局域非线性介质
空间光孤子的相互作用
光子开关和光子逻辑 相似文献
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研究了强非局域克尔介质中光束的演化规律,通过相位分析得到了空间孤子相互作用所满足 的非局域非线性薛定谔方程的简化近似模型,并获得了双光束传输的解析解.结果表明在传 输过程中相互作用的高斯光束的相位决定于它们的输入总功率.以振幅一强一弱共同传输的 高斯光束为例进行了具体研究,得到了强光和弱光的解析式,相位分析显示弱光在相当短的 传输距离之内能产生大的相移,可以通过对强光能量的调控来实现对弱光的相位调制.
关键词:
非局域克尔介质
空间光孤子
孤子相互作用
相位调制 相似文献
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光束在非局域非线性介质中传输由非局域非线性薛定谔方程描述.讨论了在不同非局域程度 条件下,空间光孤子的传输特性.提出了一个基于分步傅里叶算法数值求解孤子波形和分布 的迭代算法.假定介质的非线性响应函数为高斯型,得出了在不同非局域程度条件下空间光 孤子的数值解,并数值证明了它们的稳定性.结果表明,不论非局域程度如何,光束都能以 光孤子态在介质中稳定传输.光孤子的波形是从强非局域时的高斯型过渡到局域时的双曲正 割型,形成孤子的临界功率随非局域程度的减弱而减小,光孤子相位随距离线性增大,相位 的变化率随非局域程度的减弱而减小.
关键词:
非局域非线性薛定谔方程
空间光孤子
临界功率
相位 相似文献
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S.?Liu H.?Kn?ckel E.?Tiemann 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,60(2):269-277
We consider localized states of both single- and two-component Bose-Einstein condensates (BECs) confined in a potential resulting
from the superposition of linear and nonlinear optical lattices and make use of Vakhitov-Kolokolov criterion to investigate
the effect of nonlinear lattice on the stability of the soliton solutions in the linear optical lattice (LOL). For the single-component
case we show that a weak nonlinear lattice has very little effect on the stability of such solitons while sufficiently strong
nonlinear optical lattice (NOL) squeezes them to produce narrow bound states. For two-component condensates we find that when
the strength of the NOL (γ
1) is less than that of the LOL (V
0) a relatively weak intra-atomic interaction (IAI) has little effect on the stability of the component solitons. This is true
for both attractive and repulsive IAI. A strong attractive IAI, however, squeezes the BEC solitons while a similar repulsive
IAI makes the component solitons wider. For γ
1 > V
0, only a strong attractive IAI squeezes the BEC solitons but the squeezing effect is less prominent than that found for γ
1 < V
0. We make useful checks on the results of our semianalytical stability analysis by solving the appropriate Gross-Pitaevskii
equations numerically. 相似文献
12.
Sk Golam Ali 《Annals of Physics》2009,324(6):1194-1210
We make use of a potential model to study the dynamics of two coupled matter-wave or Bose-Einstein condensate (BEC) solitons loaded in optical lattices. With separate attention to linear and nonlinear lattices we find some remarkable differences for response of the system to effects of these lattices. As opposed to the case of linear optical lattice (LOL), the nonlinear lattice (NOL) can be used to control the mutual interaction between the two solitons. For a given lattice wave number k, the effective potentials in which the two solitons move are such that the well (Veff(NOL)), resulting from the juxtaposition of soliton interaction and nonlinear lattice potential, is deeper than the corresponding well Veff(LOL). But these effective potentials have opposite k dependence in the sense that the depth of Veff(LOL) increases as k increases and that of Veff(NOL) decreases for higher k values. We verify that the effectiveness of optical lattices to regulate the motion of the coupled solitons depends sensitively on the initial locations of the motionless solitons as well as values of the lattice wave number. For both LOL and NOL the two solitons meet each other due to mutual interaction if their initial locations are taken within the potential wells with the difference that the solitons in the NOL approach each other rather rapidly and take roughly half the time to meet as compared with the time needed for such coalescence in the LOL. In the NOL, the soliton profiles can move freely and respond to the lattice periodicity when the separation between their initial locations are as twice as that needed for a similar free movement in the LOL. We observe that, in both cases, slow tuning of the optical lattices by varying k with respect to a time parameter τ drags the oscillatory solitons apart to take them to different locations. In our potential model the oscillatory solitons appear to propagate undistorted. But a fully numerical calculation indicates that during evolution they exhibit decay and revival. 相似文献
13.
M Raj Lakshmi 《Pramana》1979,12(5):447-464
A procedure is offered for evaluating the forces between classical, charged solitons at large distances. This is employed
for the solitons of a complex, scalar two-dimensional field theory with a U(1) symmetry, that leads to a conserved chargeQ. These forces are the analogues of the strong interaction forces. The potential,U(Q, R), is found to be attractive, of long range, and strong when the coupling constants in the theory are small. The dependence
ofU(Q, R) onQ, the sum of the charges of the two interacting solitons (Q will refer to isospin in the SU(2) generalisation of the U(1) symmetric theory) is of importance in the theory of strong
interactions; group theoretical considerations do not give such information. The interaction obtained here will be the leading
term in the corresponding quantum field theory when the coupling-constants are small. 相似文献
14.
I. A. Ovid'ko 《Zeitschrift für Physik B Condensed Matter》1989,77(3):409-412
New types of spatially non-uniform excitations in icosahedral quasicrystalline lattices — solitons and coreless defects — are studied by the projection and topology techniques. The topological charges of particle-like solitons are revealed, each represents the set (z
1,z
2) of integers. The coreless defects are found to be topologically unstable excitations. 相似文献
15.
We derive rational solutions in Casoratian form for the Nijhoff-Quispel-Capel (NQC) equation by using the lattice potential Korteweg-de Vries (lpKdV) equation and two Miura transformations between the lpKdV and the lattice potential modified KdV (lpmKdV) and the NQC equation. This allows us to present rational solutions for the whole Adler-Bobenko-Suris (ABS) list except Q4. The known Miura transformation for soliton solutions between the NQC equation and Q3δ and the known degenerations for solitons from Q3δ to Q2, Q1δ, H3δ, H2 and H1 in the ABS list are used. We show that the Miura transformation and degenerations are valid as well for rational solutions which are usually considered as “long-wave-limit” of solitons. All the rational solutions can be expressed in terms of {z j} which are linear functions of (n, m). 相似文献
16.
J. W. M. Menezes J. R. R. Sousa W. B. Fraga V. C. M. Lopes F. T. Lima C. S. Sobrinho A. S. B. Sombra 《Optical and Quantum Electronics》2010,42(3):179-192
The propagation and stability of spatiotemporal optical solitons (or optical bullets) in a planar waveguide with periodically
modulated cubic-quintic nonlinearity is studied numerically as a function of the amplitudes of modulation (A
m
), the frequency of modulation (ω
m
) and the propagation distance z. The optical spatiotemporal solitons are the result of the balance between the nonlinear parameters, of dispersion (dispersion
length, L
D
) and diffraction (diffraction length, L
d
) with temporal and spatial auto-focusing behavior respectively. With the objective of ensure the stability and preventing
the collapse or the spreading of pulses, in this study we explore the cubic-quintic nonlinearity with the optical fields coupled
by XPM and take into account several values for the non linear parameter α and for amplitudes (A
m
) and frequency (ω
m
) of modulation as a function of the propagation distance z and we cause the collisions of two pulses (envelope of the optical field) to ensure that the optical pulse are solitons.
After numerical analysis of parameter settings selected four conditions and for all we get stable solitons and this paper
shown that, for a fixed amplitude and frequency of modulation we have stable spatiotemporal solitons. 相似文献
17.
N.D. Nguyen 《Optics Communications》2008,281(8):2012-2022
Bound solitons generated in actively mode-locked lasers enable new forms of pulse pairs and multiple pairs or groups of solitons in optical transmission or logics. In this paper, we present the generation of stable bound states of multiple solitons in an active mode-locked fiber laser using continuous phase modulation for wideband phase matching. Not only that dual-soliton bound states but also the triple- and quadruple-soliton pulses can be established. Simulation of the generated solitons are demonstrated. We have also prove by simulation that experimental relative phase difference and chirping caused by phase modulation of LiNbO3 modulator in the fiber loop significantly influences the interaction between the solitons and hence their stability as they circulate in the anomalous path-averaged dispersion fiber loop. 相似文献
18.
We study stationary two-dimensional solitons in an easy-axis Heisenberg magnet with the Hamiltonian density wherei=1, 2,a=1, 2, 3, and (x
i
) is the angle between unit vector s(x
i
) and the easy axis, 0<p<. Stable solitons with a topological chargeQ=1 and localized distributionss
a
(x
i
) withQ=2 are found. The existence of the bound states of two solitons withQ=1 is shown numerically for 0<p<. 相似文献
19.
C. Brunhuber F. G. Mertens Y. Gaididei 《The European Physical Journal B - Condensed Matter and Complex Systems》2004,42(1):103-112
We study the motion of envelope solitons on anharmonic atomic chains in the presence of dissipation and thermal fluctuations. We consider the continuum limit of the discrete system and apply an adiabatic perturbation theory which yields a system of stochastic integro-differential equations for the collective variables of the ansatz for the perturbed envelope soliton. We derive the Fokker-Planck equation of this system and search for a statistically equivalent system of Langevin equations, which shares the same Fokker-Planck equation. We undertake an analytical analysis of the Langevin system and derive an expression for the variance of the soliton position Var[x
s
] which predicts a stronger than linear time dependence of Var[x
s
] (superdiffusion). We compare these results with simulations for the discrete system and find they agree well. We refer to recent studies where the diffusion of pulse solitons were found to exhibit a superdiffusive behaviour on longer time scales.Received: 28 June 2004, Published online: 26 November 2004PACS:
05.10.Gg Stochastic analysis methods - 05.45.Yv Solitons - 05.40.-a Fluctuation phenomena, random processes, noise, and Brownian motion - 05.50. + q Lattice theory and statistics 相似文献
20.
We have investigated incoherent interaction between photovoltaic bright–bright soliton pairs in photorefractive crystals under steady-state condition in an unbiased series two-photon photorefractive crystal circuit in one dimension. The numerical scheme according to the Crank-Nicholson and Runge-kutta methods are applied to simulate the propagation of incoherent interaction for different normalized separation distances and different E0. Results show that in the case of one-dimensional interaction between these photovoltaic solitons, attraction occurs and width of beams decreases with increasing biased field E0 and two soliton interact in longer distance for smaller E0. The result can be used for design optical switches that controlled by biased field. 相似文献