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有偏压中心对称光折变晶体中的屏蔽孤子 总被引:1,自引:6,他引:1
给出了中心对称光折变晶体中屏蔽孤子的高阶空间电荷场.当高阶项可以忽略时,这个电荷场就变为早前在中心对称光折变晶体中研究的屏蔽孤子的空间电荷场.研究了中心对称光折变晶体中屏蔽孤子的高阶非线性波动方程.在适当的条件下,这个非线性波动方程能够展示明暗空间光孤子.这类晶体不同于非中心对称晶体,其非线性折射率的改变来源于二次电光效应,而不是一般的线性电光效应.应用光束传播的方法,对这些孤子的稳定性进行了讨论.表明在小的微扰下这类孤子是稳定的,不会发生分裂. 相似文献
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高斯光束在有外电场的中心对称光折变材料中的演化 总被引:5,自引:0,他引:5
为了研究在有外电场的中心对称光折变材料中一束高斯光束及两束高斯光束相互作用的演化,将高斯光束作为入射波,采用数值方法求解波传播方程.结果表明,当外加电场,光强峰值和束腰参量分别与晶体匹配的情况下,一束高斯光束能演化为稳定的屏蔽空间明孤子,而在不匹配时,一束高斯光束在传播过程中则呈现周期性的压缩或膨胀现象.同时也发现,在作用距离范围内.两束同相位高斯光束相互吸引,并伴随着融合现象,两束反相位高斯光束相互排斥,且排斥作用随着光束初始间距的减小而增加. 相似文献
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为了得到双光子非相干耦合光伏孤子族的结果,采用数值模拟方法,对稳态情况下多束互不相干的光束在双光子光伏光折变晶体中的传播进行了研究。结果表明:具有相同偏振和相同波长的多束互不相干的入射光束可在晶体中形成双光子非相干耦合光伏孤子族。当入射光束中仅包含两个分量时,孤子族就转化为光伏孤子对。并用双光子光伏光折变晶体Cu:KNSBN和LiNbO3进行了分析说明。研究结果可为空间光孤子理论的发展提供理论依据。 相似文献
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International Journal of Theoretical Physics - We consider a parametric oscillation driven by coherent light beams and coupled to a two-mode thermal reservoir. Applying the solutions of the quantum... 相似文献
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Solitary Wave Evolution of Optical Planar Vortices in Self-Defocusing Photorefractive Media
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Solitary wave evolution of optical planar vortices in isotropie self-defoeusing photorefractive media is investigated in detail. We demonstrate that the formation of a planar vortex soliton intensively depends on the diameter and maximum intensity of the input vortex Seam. The exact solutions of planar vortex solitons are obtained due to the Petviashvili iteration method. It is found that, with the increasing soliton maximum intensity, the soliton core will be gradually diminished to a minimum value. 相似文献
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光折变介质中四波耦合方程的一种解法及应用 总被引:2,自引:1,他引:1
提出新守恒量的基础上,推导出光折变介质中四波耦合方程的一种新解法,并讨论了这种解法在分析相位共轭光束动力学行为中的应用。 相似文献
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Feng Chen Bao-long Fang Rui He Hong-yi Fan 《International Journal of Theoretical Physics》2014,53(8):2846-2854
We explore the time-evolution law of the optical field of degenerate parametric amplifier (DPA) in dissipative channel. It turns out that its density operator at initial time ρ 0 = A exp(E ? a ?2) exp(a ? alnλ) exp(E a 2) evolves into \(\rho (t)= \frac {A}{\lambda ^{\prime }}\) \(\exp \left (\frac {E^{\ast }e^{-2\kappa t}a^{\dag 2}}{ \lambda ^{\prime 2}}\right )\exp \left \{a^{\dag }a\ln \frac {[\lambda -(\lambda ^{2}-4|E|^{2})T]e^{-2\kappa t}}{\lambda ^{\prime 2}}\right \} \exp \left (\frac { Ee^{-2\kappa t}a^{2}}{\lambda ^{\prime 2}}\right ),\) where κ is the damping constant of the channel, T = 1 ? e ?2κt , and \(\lambda ^{\prime }\equiv \sqrt {(1-\lambda T)^{2}-4|E|^{2}T^{2}}.\) We employ the method of integration (or summation) within an ordered (normally ordered or antinormally ordered) of operators to overcome the obstacles in the process of calculation. 相似文献
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LI Jiang-Fan FANG Jia-Yuan XIAO Fu-Liang LIU Xin-Hai WANG Cheng-Zhi 《理论物理通讯》2009,51(3):514-518
By properly selecting the time-dependent unitary transformation for the linear combination of the number operators, we construct a time-dependent invariant and derive the corresponding auxiliary equations for the degenerate and non-degenerate coupled parametric down-conversion system with driving term. By means of this invariant and the Lewis-Riesenfeld quantum invariant theory, we obtain closed formulae of the quantum state and the evolution operator of the system. We show that the time evolution of the quantum system directly leads to production of various generalized one- and two-mode combination squeezed states, and the squeezed effect is independent of the driving term of the Hamiltonian. In somespecial cases, the current solution can reduce to the results of the previous works. 相似文献
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光折变介质的相位共轭波强度的近似表达式 总被引:1,自引:0,他引:1
以光折变介质中非线性耦合波微分方程的一种精确解为基础,对在推导这种精确解过程中起重要作用的一个守恒量进行讨论,通过初等变换,在不同的特殊条件下得到相位共轭波强度的几处近似表达式。与报道的其它近似方法相比,本近似方法不需要建立及求解简化的微分方程因而具有普适,简单的特点。 相似文献
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The Fermi energy, density of average kinetic energy, and average density of kinetic energy of the transverse finite motion of an electron gas of a specified concentration are calculated taking into account Landau diamagnetism and Pauli paramagnetism. The kinetic energy of a longitudinal continuous electron motion along the direction of the external magnetic field H is estimated. It is shown that the kinetic energy of the longitudinal continuous motion vanishes with increase in the external magnetic field strength in the quantum limit where the maximum Landau quantum number N
m = 0. For N
m > 0, the longitudinal kinetic energy component of a degenerate electron gas somewhat increases with magnetic field strength. The cause of the erroneous result is discussed. 相似文献
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《理论物理通讯》2017,(12)
Linear analysis of low frequency obliquely propagating electrostatic waves in a partially spin polarized degenerate magnetized plasma is presented. Using Fourier analysis, a general linear dispersion relation is derived for low frequency electrostatic lower hybrid(LH) wave, ion acoustic(IA) wave and ion cyclotron(IC) wave in the presence of electron spin polarization. It is found that the electron spin polarization gives birth to a new spin-dependent wave(spin electron acoustic wave) in the spectrum of these waves. Further, the electron spin polarization also causes drastic shifts in the frequency spectrum of these waves. These effects would have a strong bearing on wave phenomena in degenerate astrophysical plasmas. 相似文献
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Doklady Physics - In this paper, we consider the problems of the dynamics of plane shock waves in media with one-dimensional longitudinal density stratification. The rationale, features, and limits... 相似文献