DFG-RSF:Controlled femtosecond super-filaments

所谓的超长丝是最近才发现的，它不同于普通长丝，因为它具有更高的自由电子强度和更高的密度。它们的出现是由于复丝束的强烈相互作用以及两根或更多根细丝的分裂所致。超细丝在所谓的无赖波的背景下引起了人们的注意。特别是，等离子体密度高一个数量级意味着光致电离产生的非线性程度更高，从而产生更高的等离子体诱导太赫兹的效率。在这个项目中，我们从实验和理论上研究了超长丝的动力学，特别是超长丝中THz的产生。实验部分将在莫斯科小组的一个新型太瓦激光设备上进行。理论部分将在莫斯科和汉诺威集团之间分配，受益于位于汉诺威的强大计算机集群设施。除了单色超细丝，我们还研究了双色超细丝作为高能亚周期太赫兹脉冲的可能来源。在我们工作的理论部分，我们将通过对超细丝中的场和电子密度的动力学进行全面的建模来支持实验。此外，我们在几个方向上扩展了理论，特别是阐明了多色(多于两色)超细丝的可能性，以及通过强声波引起原子压强的周期性变化来引入准相位匹配的可能性。

So-called super-filaments were discovered very recently and are different from common filaments by higher intensity and higher density of free electrons. They appear due to strong interaction of a multifilament bundle and fission of two and more filaments together. Super-filaments attracted attention in context of so called rogue waves. In particular, one order of magnitude higher plasma density promises higher degree of nonlinearity induced by photo-ionization, and thus, higher efficiency of plasma-induced THz generation. In this project we consider, both experimentally and theoretically, dynamics of super-filaments and in particular THz generation in super-filaments. The experimental part will be carried out in the Moscow group on a novel terawatt laser facility. Theoretical part will be divided between Moscow and Hannover group, profiting from the strong computer cluster facility in located in Hannover. Beyond single color superfilaments, we study two-colour filaments as a possible source of high-energy sub-cycle THz pulses. In theoretical part of our work we will support experiment by comprehensive modeling of the dynamics of field and electron density in superfilaments. Furthermore, we extend the theory in several directions, in particular to clarify the possibility of multi-colour (more than two-colour) super-filaments and the possibility to introduce quasi-phase matching via periodic variation of atomic pressure by a strong acoustic wave.