共查询到17条相似文献,搜索用时 70 毫秒
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理论研究了基于双光子异构非线性的非相干耦合孤子族的存在性.发现非相干耦合灰孤子族及暗孤子族可以在具有双光子异构非线性的块状聚合物中存在.若各分量成分具有相同的偏振和波长但彼此互不相干,可能形成这种孤子族.用数值方法详细地研究了这种非相干耦合灰孤子族及暗孤子族的存在条件及其特性.非相干耦合孤子族的每一个分量成分具有相同的半高全宽.当这一非相干耦合灰孤子族或暗孤子族在具有双光子光致异构非线性的聚合物中传播时,各分量成分光束都能稳定传播.研究表明,灰孤子族各分量成分具有横向运动速度,但暗孤子族不会在横向上发生移动.当这种非相干耦合孤子族只有两个分量成分时,它们自动退化成灰孤子对或暗孤子对. 相似文献
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本文从一维强非局域非线性模型出发,推导出非相干光满足的非线性薛定谔方程.按照相干密度描述方法,写出非相干光的描述方式,求出了非相干光孤子的形成条件和孤子形式,还得到了相干光和非相干光在强非局域非线性介质中形成孤子的临界功率,结果说明非相干光形成孤子时,需要更高的能量.当非相干光孤子的条件不满足时,非相干光束以呈现振荡行为.空间振荡周期仅与介质、入射的非相干光的光功率有关,而与光源的非相干角功率谱宽度及具体组分无关.同时,我们还数值模拟了这种非相干光束的振荡行为和单一组分、一对组分的非相干强度演化过程. 相似文献
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采用数值方法研究了在一个具有扩散效应的光伏光折变晶体中的非相干耦合的亮和暗光伏空间孤子对的偏转特性.结果表明,由于非相干相互作用,晶体中的一个亮孤子和一个暗孤子互相俘获,且两个孤子的中心沿着相同的轨迹移动.发现,当亮孤子的入射峰值强度不变时,通过调节暗孤子的入射背景强度可以控制亮孤子的偏转;当暗孤子的入射背景强度处于一个特殊值时,亮孤子的偏转被抑制,而当暗孤子的入射背景强度偏离这个特殊值时,亮孤子发生偏转.同样,当暗孤子的入射背景强度不变时,其偏转可以通过调节亮孤子的入射峰值强度来控制. 相似文献
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It is shown that bright-dark incoherently coupled soliton pairs can exist in photorefractive (PR) crystals under steady-state conditions, each soliton constituent of which is spatially incoherent. The characteristics of bright-dark incoherently coupled soliton pairs are studied by the coherent density approach and the intensity expressions of soliton pairs are obtained. The propagation properties of coherent components of each constituent in a soliton pair are also discussed in detail. 相似文献
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Propagation properties of bright and dark incoherent beams are numerically studied in photovoltaic-photorefractive crystal by using coherent density approach for the first time. Numerical simulations not only exhibit that bright incoherent photovoltaic quasi-soliton, grey-like incoherent photovoltaic soliton, incoherent soliton doublet and triplet can be established under proper conditions, but also display that the spatial coherence properties of these incoherent beams can be significantly affected during propagation by the photovoltaic field. 相似文献
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It is shown theoretically that incoherently coupled bright or dark spatial soliton families can be realized in biased guest-host photorefractive polymers under steady-state conditions. These soliton families can be established provided the multiple carrier beams share the same polarization, wavelength, and are mutually incoherent. These soliton families will reduce to soliton pairs when they contain only two components. Moreover, the stability of such soliton families has been discussed by the numerical method. 相似文献
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We present the observation of incoherent anti-dark photovoltaic solitons in LiNbO3:Fe crystal. This new class of soliton states involves bright photovoltaic solitons on a background beam meeting ?? > 1, where ?? is the ratio of background illumination photovoltaic constant to that of soliton beam. For ?? < 1, dark photovoltaic solitons are generated. Furthermore, this novel type solitons are investigated experimentally by injecting coherent light and partially coherent background of infinite extent. In case of spatial coherence of the background lower than the threshold of incoherent modulation instability, these results indicate that bright photovoltaic solitons can propagate in a stable fashion. 相似文献
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Chunfu Huang 《Optik》2012,123(2):140-143
We investigate numerically the interactions of partially spatially incoherent odd dark solitons in a de-focusing kerr nonlinear media based on the coherent density approach, and find that a pair of partially spatially incoherent dark solitons may be changed from repulsion to attraction with an appropriate incoherence parameter. Moreover, a pair of partially incoherent gray soliton may form under appropriate conditions. Some numerical examples are provided to illustrate their interaction behavior further. 相似文献