中红外啁啾激光驱动CO分子产生单个软X射线阿秒脉冲  

Generation of isolated soft X-ray attosecond pulse from CO molecule driven by a mid-infrared chirped laser

作　　者：赵松峰[1] 李大军 景文泉 管仲[1] 焦志宏[1] ZHAO Song-feng;LI Da-jun;JING Wen-quan;GUAN Zhong;JIAO Zhi-hong(College of Physics and Electronic Engineering,Northwest Normal University,Lanzhou 730070,Gansu,China)

机构地区：[1]西北师范大学物理与电子工程学院,甘肃兰州730070

出　　处：《西北师范大学学报（自然科学版）》2020年第2期51-57,共7页Journal of Northwest Normal University(Natural Science)

基　　金：国家自然科学基金资助项目(11664035,11765018)。

摘　　要：采用中红外啁啾激光和单极脉冲组合场驱动定向的CO分子产生了能量高达6 keV(~0.2 nm)的软X射线高次谐波.研究结果表明,用啁啾激光可实现谐波平台的显著展宽,加入单极脉冲使得谐波截止位置大幅度拓展,更重要的是在非常宽的能量范围内产生了超连续谐波.对平台区不同阶次范围的谐波进行叠加都可以合成出单个阿秒(as)脉冲,最短脉宽为26 as.结合经典轨迹模拟和量子时频分析,展示了如何通过引入啁啾和单极脉冲实现对量子路径的有效控制.The 6 keV(~0.2 nm)soft X-ray high-order harmonics from the oriented CO molecule exposed to the combination of an intense mid-infrared chirped laser and a unipolar pulse are created theoretically.The harmonic plateau can be broadened significantly using the chirped laser field and the cutoff of harmonic spectra are dramatically extended by adding a unipolar pulse.More importantly,supercontinuum harmonic spectra is obtained in a very wide energy range.By superposing some supercontinuum harmonics centered at several different central frequencies,the isolated attosecond(as)pulses out of which the shortest one is 26 as can be produced directly.Combined with the classical trajectory simulation and the quantum time-frequency analysis,quantum paths can be efficiently controlled by introducing the laser chirp and a unipolar pulse.

关 键 词：中红外啁啾激光 单极脉冲 软X射线高次谐波 单个阿秒脉冲 

分 类 号：O562.4[理学—原子与分子物理]