为了了解核运动对H+2和T+2谐波辐射强度及产生阿秒脉冲的影响, 采用数值求解薛定谔方程的方法, 理论研究了10fs和20fs激光驱动下H+2和T+2谐波截止能量附近强度的变化。结果表明, 短脉宽驱动下谐波强度满足H+2>T+2, 而长脉宽驱动下谐波强度满足T+2>H+2, 根据谐波强度变化规律, 在最佳谐波辐射强度下引入半周期激光场可以获得高强度、高能量的谐波平台区, 进而获得脉宽为37as的阿秒脉冲。该研究为探测同位素分子及产生高强度及高能量的阿秒脉冲提供了一种新的方案, 对激光光学的发展有一定帮助。

In order to understand the effect of nuclear motion of H+2 and T+ 2on harmonic intensity and attosecond pulse generation, the intensity changes in the harmonic cutoff region from H+2 and T+2 driven by a 10fs and 20fs lasers were theoretically studied by numerically solving the time-dependent Schrdinger equation. The results show that the harmonic intensity follows as H+2 > T+2 under shorter pulse duration case; it follows as T+2 > H+2 under longer pulse duration case. According to the changing law of harmonic intensity, the high intensity and high energy harmonic plateau can be obtained by introducing the half-cycle laser pulse under the optimal harmonic emission intensity, and then the attosecond pulse with pulse duration of 37as can be obtained. The study provides a new way to detect isotopic molecules and generate high intensity and high energy attosecond pulses.