圆偏振激光附加太赫兹场作用下的高次谐波发射和孤立阿秒脉冲的产生

摘要

We theoretically solve the two-dimensional time-dependent Schrödinger equation to investigate the high-order harmonic generation and isolated attosecond pulse generation of H 2+in a circularly polarized laser pulses with Terahertz field.We find that no matter add the Terahertz field to x or y direction , a continuum spec-trum can be obtained.We find that only the short trajectory contributes to high -order harmonic generation by means of time-frequency analysis.By superposing a properly selected range of the harmonic spectrum , an isola-ted attosecond pulse with a duration of 129 as or 83 as are obtained.%本文通过数值求解二维含时薛定谔方程，研究了圆偏振激光和太赫兹组合场作用下， H2＋的高次谐波发射和孤立阿秒（1 as ＝10－18 s）脉冲的产生。研究发现，无论在圆偏振激光场的x或y方向附加一个太赫兹场，都可以产生一个比较平滑的连续谐波谱。通过时频分析我们发现，高次谐波的贡献主要来自于短轨道。适当选取一些级次的连续谐波进行叠加，可以得到129 as或83 as的孤立阿秒脉冲。