共查询到20条相似文献,搜索用时 0 毫秒
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All-optical steering of the nonlinear interactions between multiple spatial solitons can be performed in an isotropic photoisomerization polymer, by propagating an external control beam in perpendicular direction. Fusing, giving birth to another new soliton, and transferring energy can take place in the interactions of signal beams, which can be achieved by changing the incident position of the control beam, the initial relative phase and the power ratio between the signal beams and the control beam. These phenomena are physically explained, and they have significantly potential applications in optical signal readdressing, logic gating, and all-optical switching, etc. 相似文献
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Higher-order space-charge field effects on the self-deflection of photovoltaic dark spatial solitons
We investigate theoretically the effects of higher-order space-charge field on the self-deflection of photovoltaic dark spatial solitons by numerical method under steady-state conditions. The expression for an induced space-charge electric field, including higher-order space-charge field terms is obtained. Numerical results indicate that photovoltaic dark solitons possess self-deflection process during propagation, and the solitons always bend in the direction of the c-axis of the crystal. The self-deflection of dark solitons can experience considerable increase especially in the regime of high photovoltaic field strengths. Relevant examples are provided. 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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We investigate the interaction of spatial dark optical soliton pair in open-circuit photovoltaic photorefractive crystals by considering the effect of background light and diffusion nonlinearity. We show that the spatial dark solitons repel each other and travel along different trajectories for the coherent interactions that one undergoes reflection and the other one deflects significantly when they are closely overlapped, and the dark solitons attract and deflect simultaneously along a parabolic trajectory for the case of incoherent interactions. The deflection distance depends on the intensities and the initial separation between the dark solitons. 相似文献
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We investigate the formation of high-order polarization vortex spatial solitons. The high-order polarization vortex solitons have novel polarization states which are different from fundamental polarization vortex solitons and have rotational symmetry only in intensity. It is proved that the polarization vortex solitons cannot carry vortex phase. The existence domain and dynamical characteristic of these high-order polarization vortex solitons in Bessel optical lattices are discussed in detail. 相似文献
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A new type of spatial solitons i.e. pyroelectric photovoltaic spatial solitons based on the combination of pyroelectric and photovoltaic effect is predicted theoretically. It shows that bright, dark and grey spatial solitons can exist in unbiased photovoltaic photorefractive crystals with appreciable pyroelectric effect. Especially, the bright soliton can form in self-defocusing photovoltaic crystals if it gives larger self-focusing pyroelectric effect. 相似文献
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Keqing Lu Kehao Li Yanpeng Zhang Changyun Miao Jingjun Xu 《Optics Communications》2010,283(23):4741-4748
We show that gray spatial optical solitons are possible in biased photorefractive polymers under steady-state conditions. We find that for a given material parameter the absolute value of a gray photorefractive polymeric soliton's phase decreases with an increase in the beam's grayness, whereas it increases with the material parameter for a given beam's grayness and that the full width half maximum (FWHM) of the gray soliton beam's intensity increases with the beam's grayness when the normalized background intensity and the material parameter are fixed and decreases with an increase in the normalized background intensity when the material parameter is fixed. On the other hand, we also show that N coupled beam evolution equations in biased photorefractive polymers can exhibit multicomponent gray solitons. These multicomponent gray solitons can be obtained provided that the N coupled beams share the same polarization, wavelength, and are incoherent with one another. The characteristics and stability properties of these multicomponent gray solitons are also discussed in detail. 相似文献
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采用数值模拟方法研究光折变晶体中的高阶耦合光伏空间孤子.该孤子可用包含两种频率的四束平行光入射到折射率改变为正的光折变晶体中形成.数值研究还发现,当入射光束为双曲正割光束时,在一定条件下可以模拟高阶耦合光伏空间孤子,而且,这种高阶耦合光伏空间孤子显示出光控光的特性.入射光束显著偏离左右对称会影响高阶耦合光伏空间孤子的实现.
关键词:
耦合光伏空间孤子
光控光 相似文献
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The wave equation of TM polarized subwavelength beam propagations in a nonlinear planar waveguide is derived beyond the paraxial approximation. This modified equation contains more higher-order linear and nonlinear terms than the nonlinear Schrödinger equation. The propagation of fundamental subwavelength spatial solitons is numerically studied. It is shown that the effect of the higher nonlinear terms is significant. That is, for the propagation of narrower beam the modified nonlinear Schrödinger equation is more suitable than the nonlinear Schrödinger equation. 相似文献
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We investigate theoretically the time behavior of spatial solitons in biased centrosymmetric photorefractive crystals. A one-dimensional time-dependent wave propagation equation in biased centrosymmetric photorefractive crystals is presented. It is shown that the bright solitons exist in both quasi-steady-state and steady-state regimes for high saturation values. When the intensity ratio is smaller than unity, the bright soliton width decreases monotonically to a minimum value toward steady state. Moreover, the time-dependent nonlinear wave equation exhibits only steady-state screening dark spatial solitons. 相似文献
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Yihong Qi 《Optics Communications》2010,283(7):1471-281
We study steering of weak-light solitons in a resonant lambda-type atomic system. Signal soliton steering can be realized via input angle and power control of the control soliton. It is shown that, the deflection angle of a vertical input signal soliton increases linearly with the increase of the input angle of the control soliton due to the repulsive effect in collision, and thus leads to the increase of the output position shift of the signal soliton. When a signal soliton is input parallel with a control soliton, the output position shift of the signal soliton depends parabolically on the normalized power of the control soliton. Decreasing their soliton separation can increase the output position shift of the signal soliton. These properties may be useful in all-optical soliton switching and optical information processing, etc. 相似文献
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The effects of diffusion on self-deflection of steady-state bright spatial solitons in biased centrosymmetric photorefractive crystals are investigated systematically by both numerical and perturbation methods. The results show that the soliton propagates along a parabolic trajectory and the central spatial frequency component shifts linearly with the propagation distance. Both the deflection effects vary cubically with applied external bias field. 相似文献
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分别用数值法和微扰法研究了考虑背景光时光伏暗空间孤子的自偏转特性.与亮孤子不同,暗孤子光束中心的运动轨迹不为抛物线.在归一化的直角坐标系(ξ,ζ)中,暗孤子朝ξ>0的方向偏转;同时,暗孤子光束中心光强发生改变.通过调节晶体对信号光和背景光的有效光伏系数之比r或信号光光强可以控制它的自偏转.还用数值方法研究了灰空间孤子的自偏转特性,发现灰孤子光束自偏转特性依赖于横向初速度v.当v>0时,灰孤子光束朝ξ>0的方向
关键词:
光伏空间暗孤子
光伏空间灰孤子
扩散效应
自偏转 相似文献
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The internal modes of incoherent vector solitons (IVSs) in
photovoltaic photorefractive materials are investigated in the
framework of coupled nonlinear Schr\"{o}dinger equations. It is found
that there is a pair of internal modes corresponding to a
bright--bright IVS. The propagation dynamics of the bright-bright IVS
perturbed by the internal modes is simulated by numerical method. 相似文献