Ding C, Korotkova O, Zhao D, Li D, Zhao Z, Pan L
Opt Express. 2020 Mar 2;28(5):7463-7474. doi: 10.1364/OE.386598.
In this paper, the propagation of Temporal Coherence Grating (TCG) pulse trains in a dispersive medium with a chirp is investigated for the first time. The two-time mutual coherence function of the TCG pulse trains propagating through extended dispersive medium specified by temporal ABCD matrix is derived and the evolution of their mean intensity and temporal degree of coherence (DOC) is explored. It is shown that the distribution of the mean intensity can be modulated freely by the number of grating lobes N, grating constant a, pulse duration T, power distributions vn, group-velocity dispersion coefficient β and the medium chirper s. Upon dispersive-medium propagation, the single pulse splits into N+1 subpulses with the same or different peak intensities which depend on power distributions vn. What's more, during the propagation the pulse self-focusing occurs being the chirp-induced non-linear phenomenon. And the distribution of temporal DOC will degenerate into Gaussian form from initial periodic coherence distribution with increasing propagation distance z or adjusting incident pulse parameters and medium dispersion. The physical explanation and numerical illustrations relating to the pulse behavior are included.
本文首次研究了具有啁啾的时间相干光栅（TCG）脉冲序列在色散介质中的传播。推导了通过由时间ABCD矩阵指定的扩展色散介质传播的TCG脉冲序列的二次互相关函数，并探讨了其平均强度和时间相干度（DOC）的演化。结果表明，平均强度的分布可以通过光栅瓣数N、光栅常数a、脉冲持续时间T、功率分布vn、群速度色散系数β和介质啁啾器s自由调制。在色散介质传播时，单个脉冲分裂成N + 1个具有相同或不同峰值强度的子脉冲，这取决于功率分布vn。此外，在传播过程中会发生脉冲自聚焦，这是一种啁啾诱导的非线性现象。并且随着传播距离z的增加或调整入射脉冲参数和介质色散，时间DOC的分布将从初始的周期性相干分布退化为高斯形式。文中包含了与脉冲行为相关的物理解释和数值说明。
