Kartashov Yaroslav V, Ye Fangwei, Konotop Vladimir V, Torner Lluis
ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain.
Institute of Spectroscopy, Russian Academy of Sciences, Troitsk, Moscow 108840, Russia.
Phys Rev Lett. 2021 Oct 15;127(16):163902. doi: 10.1103/PhysRevLett.127.163902.
We predict that photonic moiré patterns created by two mutually twisted periodic sublattices in quadratic nonlinear media allow the formation of parametric solitons under conditions that are strongly impacted by the geometry of the pattern. The question addressed here is how the geometry affects the joint trapping of multiple parametrically coupled waves into a single soliton state. We show that above the localization-delocalization transition the threshold power for soliton excitation is drastically reduced relative to uniform media. Also, the geometry of the moiré pattern shifts the condition for phase matching between the waves to the value that matches the edges of the eigenmode bands, thereby shifting the properties of all soliton families. Moreover, the phase-mismatch bandwidth for soliton generation is dramatically broadened in the moiré patterns relative to latticeless structures.
我们预测，在二次非线性介质中由两个相互扭曲的周期性子晶格产生的光子莫尔条纹图案，能够在受图案几何形状强烈影响的条件下形成参量孤子。这里要解决的问题是，几何形状如何影响多个参量耦合波联合捕获到单个孤子态。我们表明，在局域化 - 非局域化转变之上，相对于均匀介质，孤子激发的阈值功率会大幅降低。此外，莫尔条纹图案的几何形状将波之间的相位匹配条件移动到与本征模带边缘相匹配的值，从而改变了所有孤子族的特性。而且，相对于无晶格结构，莫尔条纹图案中孤子产生的相位失配带宽显著拓宽。
