摘要
提出一种直接得到脉宽稳定的单个宽谱阿秒脉冲的新方法.利用波长为800 nm脉宽为5 fs的超短脉冲叠加上偏振方向与主脉冲成π/3,脉宽同样为5 fs的二次谐波脉冲驱动氦原子,可以得到宽度达到50 eV的超连续谱.当二次谐波的强度大于1014W/cm2时,超连续谱的位置以及谱宽几乎不会随着二次谐波脉冲的强度的改变而改变.对85—125 eV的超连续谱进行滤波可以直接得到100 as左右的单个阿秒脉冲,这个性质对于实验上获得单个宽谱阿秒脉冲而言是非常有利的.
A new method to generate isolated broadband attosecond pulses with stable pulse duration is proposed. By adopting a fewcycle driving pulse combined with its second harmonic field, of which the polarization angle is π/3 to the driving pulse, the short path is well selected and a smooth supercontinuum with the bandwidth of about 50 eV is observed. For the intensity of the second harmonic field higher than 1014 W/cm^2 , the intensity variation of the second harmonic field can hardly affect the location and the bandwidth of the generated supercontinuum. Pure isolated attosecond pulses with the duration of about 100 as can be generated by directly filtering out a supercontinuum from 85--125 eV, which facilitates the experimental implement for the isolated attosecond pulse generation.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2009年第7期4914-4919,共6页
Acta Physica Sinica
基金
教育部博士点基金(批准号:20040487023)
国家自然科学基金(批准号:10774054)资助的课题~~
