共查询到20条相似文献,搜索用时 78 毫秒
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We show theoretically and experimentally in an optical fiber system that solitons can be spontaneously generated from incoherent light in an instantaneous response nonlinear Kerr medium. The theory reveals that the unexpected existence of these incoherent solitons relies on a phase-locking mechanism, which leads to the emergence of a mutual coherence between the incoherent waves that constitute the soliton. 相似文献
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Coskun TH Christodoulides DN Kim YR Chen Z Soljacic M Segev M 《Physical review letters》2000,84(11):2374-2377
We present the first observation of incoherent antidark spatial solitons in noninstantaneous nonlinear media. This new class of soliton states involves bright solitons on a partially incoherent background of infinite extent. In the case where the nonlinearity is of the Kerr type, their existence is demonstrated analytically by means of an exact solution. Computer simulations and experiments indicate that these incoherent antidark solitons can propagate in a stable fashion provided that the spatial coherence of their background is reduced below the incoherent modulation instability threshold. 相似文献
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基于相干密度理论,数值地研究了在饱和对数非线性介质中多个部分非相干光空间孤子之间的相互作用. 数值结果表明,在非相干参量较小情况下,非相干光孤子的相互作用与相干光孤子的相互作用规律较类似. 当非相干参量较大时,强的非相干性模糊了孤子之间的相位关系,孤子间的相互作用主要以非相干相互吸引作用为主. 特别是在非相干参量较大而且孤子初始相对相位差为π的情况下,多个部分非相干光孤子可并行传播形成稳定的阵列孤子. 利用多个非相干光孤子的不同相互作用形态写入各种阵列波导,为实现光控制光、导向光提供了一种可能性.
关键词:
多个部分非相干光空间孤子
空间光孤子的相互作用
相干密度理论
饱和对数非线性 相似文献
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We present a simple and straightforward approach to investigate coupled spatial-soliton pairs of two copropagating mutually incoherent (i.e., both beams are fully spatially and temporally coherent, but are incoherent with respect to one another) light beams in saturable nonlinear media. The approach provides a deeper understanding of coupled spatial-soliton pairs and reveals many interesting features, including the entire existence curve of such solitons. 相似文献
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We study numerically the formation and interactions of incoherent white-light solitons in a nonlinear media with logarithmic saturable nonlinearity based on the coherent density approach. We find that not only the formation but also the interactions of incoherent white-light solitons are fundamentally a collective effect, where all the frequencies participate in the process, and self-adjust their respective contributions to the formation and interactions. We find that the interactions of incoherent white-light solitons in logarithmic media are always attractive. 相似文献
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We study the properties of surface solitons generated at the edge of a semi-infinite photonic lattice in nonlinear quadratic media, namely two-color surface lattice solitons. We analyze the impact of phase mismatch on the existence and stability of nonlinear surface modes and find novel classes of two-color twisted surface solitons, which are stable in a large domain of their existence. 相似文献
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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
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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
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We demonstrate experimentally the existence of two transverse-dimensional counterpropagating (CP) incoherent spatial solitons in a 5 x 5 x 23 mm SBN:60Ce photorefractive crystal and investigate their dynamical behavior. We carry out numerical simulations that confirm our experimental findings. Substantially different behavior from the copropagating incoherent solitons is found. A symmetry breaking transition from stable overlapping CP solitons to unstable transversely displaced CP solitons is observed. We perform linear stability analysis that predicts the threshold for the split-up transition, in qualitative agreement with numerical simulations and experimental results. 相似文献
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Waveguides formed by incoherent dark solitons 总被引:5,自引:0,他引:5
We demonstrate experimentally optical guidance of coherent light beams, using incoherent light. Such guidance is made possible by generation of partially spatially incoherent self-trapped dark beams (dark incoherent solitons) in a noninstantaneous nonlinear medium. In the one-dimensional case, the incoherent solitons induce single and Y-junction planar waveguides, whereas in the two-dimensional case, they form circular waveguides. These experiments introduce the possibility of controlling high-power laser beams with low-power incoherent light sources such as LED's or lightbulbs. 相似文献
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The propagation of elliptic incoherent beam in strongly nonlocal media with noninstantaneous anisotropic Kerr nonlinearity is systematically investigated. Using the mutual coherence function approach, we obtain the existence curve of such solitons and an interesting outcome: correlation characteristics of the elliptic incoherent solitons can be anisotropic as well as isotropic. When the existence conditions of solitons are not satisfied, the elliptic incoherent beam will undergo periodic oscillation. Nonstationary evolution behaviors of the elliptic beam are shown in detail by numerical calculation. It is also obtained that the oscillation periods of the beam in x and y direction are different and the elliptic beam will become circular at some propagation distance under special conditions. 相似文献
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We demonstrate, theoretically and experimentally, incoherent surface solitons in a noninstantaneous nonlocal nonlinear media. These incoherent surface waves are located at the interface between a nonlinear medium with long-range nonlocality and a linear dielectric medium (air). 相似文献
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By the use of theory of optical solitons, nonlinear equations governed by screening photorefractive photovoltaic solitons are introduced. By means of numerical methods, intensity profile, refractive index change of the media and also stability under propagation are investigated. Self-bending of solitons under first-order diffusion is also studied. Besides, incoherent coupled bright-bright soliton pairs and incoherent interaction are studied. 相似文献
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We show the existence of new stationary solutions in the form of domain wall soliton in the nonlinear Schrödinger-Poisson equations describing the dynamics of quantum electron plasmas. It is found that the domain wall soliton exists at strong coupling constant regime and shows a different dynamical behavior in comparison with the previously found dark and gray solitons. The robustness and the conservation of the energy of the domain wall solitons is demonstrated by numerical simulations. 相似文献
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We study the propagation of elliptic incoherent accessible solitons in strongly nonlocal media with noninstantaneous Kerr nonlinearity. For this soliton to exist, the coherence properties of the incoherent beam should be anisotropic. The total power of the incident beam should also equal to a critical value which depend on the beam width as well as the coherence properties. When initial parameters of the beam do not satisfy the existence conditions, the elliptic incoherent accessible solitons will undergo linear harmonic oscillation in different states. Corresponding properties are studied in detail. 相似文献
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We uncover a strong coupling between nonlinearity and diffraction in a photonic crystal at the supercollimation point. We show that this is modeled by a nonlinear diffraction term in a nonlinear-Schr?dinger-type equation in which the properties of solitons are investigated. Linear stability analysis shows solitons are stable in an existence domain that obeys the Vakhitov-Kolokolov criterium. In addition, we investigate the influence of the nonlinear diffraction on soliton collision scenarios. 相似文献