不同激光等离子体条件下的阿秒光脉冲产生

通过一维粒子模拟研究了利用相对论少周期强激光与固体密度等离子体表面相互作用实现单个孤立阿秒光脉冲产生的参数条件。主要研究描述相互作用的多维参数，如激光强度、入射角和等离子体标尺长度等，对相对论高次谐波能量转换效率和孤立阿秒光脉冲分离度的影响。研究发现，虽然激光等离子体参数对阿秒光脉冲产生的影响是复杂的，但是存在着能够实现大能量孤立阿秒光脉冲的最佳等离子体标尺长度和最佳入射角。当其他相互作用条件确定时，使用中等强度的相对论强激光可以在较宽的参数范围内实现孤立的阿秒光脉冲。大角度入射时，孤立阿秒光脉冲的分离度较高，能够实现孤立阿秒光脉冲的相互作用参数范围也较宽。

Attosecond light pulses in simulations using various laser plasmas

The generation of single isolated attosecond light pulses from the interaction of relativistic few-cycle lasers with solid density plasma surfaces is investigated using one dimensional particle-in-cell simulations. The primary subject of the study is the effects of the multi-parameter combinations which uniquely define the laser plasma interactions, on the laser to relativistic high-order harmonic energy conversion efficiencies, and also on the single attosecond light pulse isolation degrees. Here these multi-parameters include laser intensities, incidence angles, plasma scale lengths, etc. The impact of laser-plasma interaction parameters on attosecond light pulse generations is generally complicated. However, there exist an optimal plasma scale length and an optimal incidence angle to efficiently generate high-order harmonics and intense attosecond light pulses. When other parameters are fixed, a moderately intense relativistic laser is more advantageous to realize isolated attosecond light pulses with a broad controlling parameters range. And a larger incidence angle favors a higher isolation degree as well as a broader range of controlling parameters towards the generation of intense isolated attosecond light pulses.