Kardaś Tomasz M, Stepanenko Yuriy, Radzewicz Czesław
Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.
Department of Physics, Institute of Experimental Physics, University of Warsaw, Pasteura 5, 02-093, Warsaw, Poland.
Sci Rep. 2018 Sep 25;8(1):14350. doi: 10.1038/s41598-018-32676-9.
A novel method for numerical modelling of noncollinear and nonlinear interaction of femtosecond laser pulses is presented. The method relies on a separate treatment of each of the interacting pulses by it's own rotated unidirectional pulse propagation equation (UPPE). We show that our method enables accurate simulations of the interaction of pulses travelling at a mutual angle of up to 140°. The limit is imposed by the unidirectionality principal. Additionally, a novel tool facilitating the preparation of noncollinear propagation initial conditions - a 3D Fourier transform based rotation technique - is presented. The method is tested with several linear and nonlinear cases and, finally, four original results are presented: (i) interference of highly chirped pulses colliding at mutual angle of 120°, (ii) optical switching through cross-focusing of perpendicular beams (iii) a comparison between two fluorescence up-conversion processes in BBO with large angles between the input beams and (iv) a degenerate four-wave mixing experiment in a boxcar configuration.
提出了一种用于飞秒激光脉冲非共线和非线性相互作用数值建模的新方法。该方法依赖于通过其自身的旋转单向脉冲传播方程（UPPE）对每个相互作用脉冲进行单独处理。我们表明，我们的方法能够精确模拟相互成高达140°角传播的脉冲之间的相互作用。该限制由单向性原理施加。此外，还提出了一种有助于准备非共线传播初始条件的新工具——基于三维傅里叶变换的旋转技术。该方法在几个线性和非线性情况下进行了测试，最后给出了四个原始结果：（i）相互成120°角碰撞的高啁啾脉冲的干涉，（ii）通过垂直光束的交叉聚焦实现光开关，（iii）在输入光束之间具有大角度的BBO中两种荧光上转换过程的比较，以及（iv）在箱式配置中的简并四波混频实验。
