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201.
Self-deflection of a bright soliton in a separate bright-dark spatial soliton pair based on a higher-order space charge field 下载免费PDF全文
The self-deflection of a bright solitary beam can be controlled by a dark solitary beam via a parametric coupling effect between the bright and dark solitary beams in a separate bright-dark spatial soliton pair supported by an unbiased series photorefractive crystal circuit. The spatial shift of the bright solitary beam centre as a function of the input intensity of the dark solitary beam (\hatρ) is investigated by taking into account the higher-order space charge field in the dynamics of the bright solitary beam via both numerical and perturbation methods under steady-state conditions. The deflection amount (Δs_0), defined as the value of the spatial shift at the output surface of the crystal, is a monotonic and nonlinear function of \hatρ. When \hatρ is weak or strong enough, Δs_0 is, in fact, unchanged with \hatρ, whereas Δs_0 increases or decreases monotonically with \hatρ in a middle range of \hatρ. The corresponding variation range (δs) depends strongly on the value of the input intensity of the bright solitary beam (r). There are some peak and valley values in the curve of δs versus r under some conditions. When \hatρ increases, the bright solitary beam can scan toward both the direction same as and opposite to the crystal's c-axis. Whether the direction is the same as or opposite to the c-axis depends on the parameter values and configuration of the crystal circuit, as well as the value of r. Some potential applications are discussed. 相似文献
202.
Diffusion-induced deflection and the effect of two-wave mixing gain on dissipative photovoltaic solitons 总被引:1,自引:0,他引:1 下载免费PDF全文
In an open-circuit dissipative photovoltaic (PV) crystal, by
considering the diffusion effect, the deflection of bright
dissipative photovoltaic (DPV) solitons has been investigated by
employing numerical technique and perturbational procedure. The
relevant results show that the centre of the optical beam moves along
a parabolic trajectory, while the central spatial-frequency component
shifts linearly with the propagation distance; furthermore, both the
spatial deflection and the angular derivation are associated with the
photovoltaic field. Such DPV solitons have a fixed deflection degree
completely determined by the parameters of the dissipative system.
The small bending cannot affect the formation of the DPV soliton via
two-wave mixing. 相似文献
203.
基于将Maxweil方程与四能级原子系统速率方程相结合而建立起的随机激光时域理论,并利用有限时域差分法,研究了一维随机激活介质中激光模式的输出强度与抽运速率之间的关系.结果表明,与传统激光模式相似,随机激光模式的强度随抽运速率的变化不仅具有阈值特性,而且具有饱和特性.用模式的空间区域来表征模式的局域化程度,发现局域化程度越强的模式,阈值越低.不过,这种关系不是一一对应的.这表明模式的局域化程度是决定阈值大小的重要因素,但不是唯一的因素. 相似文献
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