论文标题
Terahertz代
Tilted-pulse-front schemes for terahertz generation
论文作者
论文摘要
高能量单一至几个周期的Terahertz脉冲可以探索科学领域，例如电子加速度，强场物理学和光谱。产生这种Terahertz脉冲的一种重要方法是使用倾斜脉冲（TPF）技术。但是，由于非连续性相匹配，大角度分散剂会导致光泵的空间和时间分解，从而限制了Terahertz的产生效率，并降低了生成的Terahertz领域的几个周期特征。为了减少角度分散引起的影响，已经提出了多种具有离散脉冲前倾斜的方案。我们提出了一种Terahertz的生成方案，其中使用了时空的搅动（STC）泵脉冲。借助我们的2D+1个数值模型，我们对常规TPF方案，三个离散TPF方案和STC方案进行了系统的比较研究。与简单的1D模型相比，该模型可以预测较小的最佳相互作用长度和明显较小的转换效率。我们得出的结论是，STC方案在空间上提供了最高的转化效率的差不多的几个循环terahertz脉冲。此外，如果相互作用长度短，离散的TPF方案不能超越连续性。通常，这项工作为给定Terahertz实验选择最合适的设置提供了指导
High energy single- to few-cycle terahertz pulses enable the exploration of the frontier of science, such as electron acceleration, strong-field physics, and spectroscopy. One important method of generating such terahertz pulses is to use the tilted-pulse-front (TPF) technique. However, due to the non-collinear phase-matching, the large angular dispersion leads to a spatial and temporal break-up of the optical pump, limiting the terahertz generation efficiency and reducing the few-cycle character of the generated terahertz fields. To reduce the effects caused by angular dispersion, multiple schemes with discrete pulse-front-tilt have been suggested. We propose a terahertz generation scheme, where a spatio-temporally chirped (STC) pump pulse is utilized. With our 2D+1 numerical model, we perform a systematic comparative study of the conventional TPF scheme, three discrete TPF schemes, and the STC scheme. This model predicts smaller optimal interaction length and significantly smaller conversion efficiency compared to simple 1D models. We conclude that the STC scheme delivers spatially homogeneous few-cycle terahertz pulses with the highest conversion efficiency. Additionally, given a short interaction length, the discrete TPF schemes cannot outperform the continuous ones. In general, this work gives guidance to choose the most appropriate setup for a given terahertz experiment
