层流混沌的实验研究：时变时滞与噪声非线性系统。

Laminar Chaos in Experiments: Nonlinear Systems with Time-Varying Delays and Noise.

机构信息

Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA.

Department of Physics, University of Maryland, College Park, Maryland 20742, USA.

出版信息

Phys Rev Lett. 2019 Oct 11;123(15):154101. doi: 10.1103/PhysRevLett.123.154101.

DOI:10.1103/PhysRevLett.123.154101

PMID:31702295

Abstract

A new type of dynamics called laminar chaos was recently discovered through a theoretical analysis of a scalar delay differential equation with time-varying delay. Laminar chaos is a low-dimensional dynamics characterized by laminar phases of nearly constant intensity with periodic durations and a chaotic variation of the intensity from one laminar phase to the next laminar phase. This is in stark contrast to the typically observed higher-dimensional turbulent chaos, which is characterized by strong fluctuations. In this Letter we provide the first experimental observation of laminar chaos by studying an optoelectronic feedback loop with time-varying delay. The noise inherent in the experiment requires the development of a nonlinear Langevin equation with variable delay. The results show that laminar chaos can be observed in higher-order systems, and that the phenomenon is robust to noise and a digital implementation of the variable time delay.

摘要

最近，通过对时变时滞标量时滞微分方程的理论分析，发现了一种新型的动力系统，称为层流混沌。层流混沌是一种低维动力系统，其特征是具有周期性持续时间的几乎恒定强度的层流相，以及强度从一个层流相到下一个层流相的混沌变化。这与通常观察到的具有强波动的高维湍流混沌形成鲜明对比。在这封信中，我们通过研究具有时变时滞的光电反馈环首次实验观测到了层流混沌。实验中固有的噪声要求开发具有时变时滞的非线性朗之万方程。结果表明，层流混沌可以在高阶系统中观察到，并且该现象对噪声和时变延迟的数字实现具有鲁棒性。