利用两色组合激光场驱动氦原子产生单个阿秒脉冲  

Isolated attosecond pulse generated by a model helium atom exposed to the combined field

作　　者：黄峰[1] 李鹏程[1] 周效信[1] 

机构地区：[1]西北师范大学物理与电子工程学院,甘肃省原子分子物理与功能材料重点实验室,兰州730070

出　　处：《物理学报》2012年第23期187-192,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11044007;11047016;11264036);高等学校博士学科点专项科研基金(批准号:20096203110001);西北师范大学创新基金(批准号:NWNU-KJCXGC-03-62)资助的课题~~

摘　　要：对由波长为1600 nm和800 nm两色激光形成组合场驱动氦原子产生的高次谐波进行了研究,通过改变组合场中主要发射高次谐波期间电场的上升沿和下降沿随时间不同的变化率,使电子长路经和短路径发射谐波的特性发生变化,将由此产生的高次谐波进行叠加时可以得到更短的阿秒脉冲,再调节两束激光场的延迟时间,能够有效地实现抑制电子短路径的贡献,从而得到脉宽为33.7 as的单个阿秒脉冲.We theoretically study the high-order harmonic generation （HHG） of a model He atom exposed to a combined field of 1600 nm and 800 nm laser pulses. The changing of rising rate and falling rate with time for the combined filed during main HHG, can present the different characteristics of high-order harmonic generation from the short electron trajectories and the long electron trajectories. By superimposing several harmonics generated from He atom driven by the combined field, we could obtain shorter attosecond pulses. Fi- nally, by adjusting the time delay between two laser pulses, we can effectively suppress the contribution of the short electron trajectories to HHG, and obtain an isolated attosecond pulse with duration 33.7 as.

关 键 词：组合场 高次谐波 阿秒脉冲 

分 类 号：O437[机械工程—光学工程] O562[理学—光学]