论文标题
多模纤维中自相似抛物线脉冲演化的时空动力学
Spatiotemporal Dynamics of Self-Similar Parabolic Pulse Evolution in Multimode Fibers
论文作者
论文摘要
在本文中，我们首次研究了多模纤维（MMFS）自相似抛物线脉冲演化的时空动力学。我们介绍了分级和步骤索引MMF中抛物线脉冲存在的数值预测，并证明抛物线脉冲形成过程可能对两个纤维中的时空行为产生显着影响。我们研究输入脉冲能及其初始模态组成对所得抛物线脉冲和相应的空间束轮廓的影响。当基本模式大多激发时，脉冲会以抛物线强度形状演变成线性chi脉的脉冲，在两个纤维中都可以传播自相似。这允许以低于40 fs脉冲持续时间的效率和高质量的脉冲压缩。还报告了对输入脉冲形状的依赖性，其Chirp参数和符号转换为抛物线形状。我们使用失配参数量化了抛物线脉冲的重塑。我们演示了所有模式相等能量分布的初始条件的抛物线脉冲演变的途径。此外，我们还观察到，对于具有不同初始脉冲能的同一MMF，输出场的束轮廓可能不同。此外，研究了一种特定模式的时空非线性动力学，自动选择光束。因此，保持空间稳定的输入脉冲能量变化十多年。抛物线脉冲形成过程在这些非线性动力学中起关键作用。这种方法提供了另一个框架，以了解MMF中复杂的非线性动力学。
In this paper, we investigate for the first time, the spatiotemporal dynamics of self-similar parabolic pulse evolution in multimode fibers (MMFs). We present numerical predictions of the existence of parabolic pulse in a graded and step index MMFs and demonstrate that the parabolic pulse formation process could have a prominent effect on the spatiotemporal behavior in both fibers. We study the effect of the input pulse energy and its initial modal composition on the resulting parabolic pulse and the corresponding spatial beam profile. When the fundamental mode is mostly excited, the pulse evolves into a linearly chirped pulse with parabolic intensity shape that propagates self-similarly in both fibers.This allows for efficient and high-quality pulse compression with sub-40 fs pulse duration. Dependence on input pulse shapes, its chirp parameter and sign towards conversion into parabolic shape are also reported. We quantify the reshaping of the parabolic pulse using the misfit parameter. We demonstrate a route to the parabolic pulse evolutions for all modes equal energy distributed initial condition. In addition, we also observe that the beam profiles of output fields could be different for same MMF with different initial pulse energy. Moreover, a spatiotemporal nonlinear dynamic, auto-selection beam of one specific mode is investigated. Thus remain spatio-temporally stable for more than a decade of the input pulse energy variation. Parabolic pulse formation process plays critical roles in these nonlinear dynamics. This approach provides another framework to understand the complex nonlinear dynamics in MMFs.
