摘要
为了调控谐波辐射过程,采用数值求解3维薛定谔方程的方法,进行了啁啾激光对调控谐波辐射截止能量及强度的理论分析。通过分析激光包络图、电子电离几率、谐波辐射时频分析图,给出了谐波截止能量延伸以及谐波强度增强的原因。结果表明,在负向啁啾场下,谐波截止能量附近的强度与无啁啾参量相比增强了1个数量级;当引入半周期调控激光场后,谐波截止能量得到有效延伸;适当叠加谐波谱上的谐波,可获得一个46as的脉冲;该脉冲强度比无啁啾参量下获得的脉冲强1个数量级。该研究对调控谐波的辐射过程及阿秒脉冲的输出是有帮助的。
In order to control the harmonic emission process, the chirp pulse control on the harmonic cutoff and the harmonic intensity was theoretically investigated by using 3-D Schr(o)dinger equation.Laser profiles, ionization probabilities, time-frequency analyses of the harmonic spectra were shown to explain the extension and the enhancement of harmonic spectra.The results show that the intensity of the harmonic cutoff region in the presence of the down-chirp pulse is enhanced by one order of magnitude in comparison with the chirp-free pulse case.By properly adding a half-cycle controlling pulse, the harmonic cutoff is remarkably extended.By superposing a properly selected harmonics, a 46as pulse can be produced.The intensity of the generated pulse is one order of magnitude higher than that from the chirp-free case.The investigation is helpful to control the harmonic emission and to produce the attosecond pulse.
出处
《激光技术》
CAS
CSCD
北大核心
2017年第5期708-711,共4页
Laser Technology
基金
国家自然科学基金资助项目(11504151)
辽宁省博士科研启动基金资助项目(201501123)
辽宁省教育厅基金资助项目(L2014242
JL201615405)
关键词
激光光学
3维薛定谔方程
高次谐波
半周期激光场
阿秒脉冲
laser optics
3-D Schr(o)dinger equation
high-order harmonic generation
half-cycle pulse
attosecond pulse
