强时间非局域系统中自相位调制诱导的“脉冲镜像”啁啾∗

摘要

非局域非线性是目前非线性光学乃至非线性科学研究领域的热点。本文研究了时间非局域系统中的脉冲啁啾特性，发现了一个非常有趣的现象：当系统的时间非局域程度很强时，由自相位调制引起的非线性啁啾可以近似成为脉冲强度的“镜像”，并且，这种特性与脉冲包络的具体形式无关。利用这种特性，分析了脉冲在强时间非局域系统中传输的时间演化过程。%Nonlocal nonlinearity is one of the hottest topics in the nonlinear optics and even the nonlinear science. In this paper, the frequency chirp induced by the self-phase modulation (SPM) in a high noninstantaneous medium is investigated. It is found that the temporal distribution of the SPM-induced chirp can be approximated by the “inverted image” of the pulse intensity in the highly noninstantaneous limit. Moreover, this property does not depend on the envelope of the pulse. By using these properties, the temporal characteristics of the pulse propagation in a highly noninstantaneous medium is analyzed.