论文标题
气体中有效产生高阶谐波
Efficient generation of high-order harmonics in gases
论文作者
论文摘要
气体中的高阶谐波产生（HHG）导致短脉冲极端紫外线（XUV）辐射在许多应用中有用，例如Attosecond Science和Nanscale Imaging。但是，此过程取决于许多参数，并且关于如何选择目标几何以优化源效率仍然没有共识。在这里，我们回顾了HHG的物理学，重点是非线性相互作用的宏观方面。我们使用数值建模和分析表达式分析了培训激光器对HHG转换效率（CE）的中等长度，压力，介质的位置和强度的影响。我们发现，如果遵循某个双曲线方程，则可以在大量的压力和中长度上实现有效的高阶谐波产生。但是，生成的辐射的空间和时间特性在很大程度上取决于压力和中长的选择。我们的结果解释了高效HHG的气体目标设计中的大量多功能性，并为将来的高流量XUV来源提供了设计指南。
High-order harmonic generation (HHG) in gases leads to short-pulse extreme ultraviolet (XUV) radiation useful in a number of applications, for example, attosecond science and nanoscale imaging. However, this process depends on many parameters and there is still no consensus on how to choose the target geometry to optimize the source efficiency. Here, we review the physics of HHG with emphasis on the macroscopic aspects of the nonlinear interaction. We analyze the influence of medium length, pressure, position of the medium and intensity of the driving laser on the HHG conversion efficiency (CE), using both numerical modelling and analytical expressions. We find that efficient high-order harmonic generation can be realized over a large range of pressures and medium lengths, if these follow a certain hyperbolic equation. The spatial and temporal properties of the generated radiation are, however, strongly dependent on the choice of pressure and medium length. Our results explain the large versatility in gas target design for efficient HHG and provide design guidance for future high-flux XUV sources.
