Wang Baoning, He Lixin, Yuan Hua, Zhang Qingbin, Lan Pengfei, Lu Peixiang
Opt Express. 2018 Dec 10;26(25):33440-33452. doi: 10.1364/OE.26.033440.
Carrier-envelope phase (CEP) dependence of high-order harmonic generation (HHG) from H2+ in a multi-cycle laser pulse is investigated by solving the non-Born-Oppenheimer time-dependent Schrödinger equation (TDSE). It is found that high harmonics in the plateau exhibit counterintuitive frequency modulation (FM) as the CEP of the multi-cycle laser varies. Based on the classical electron trajectories and time-frequency analysis, this multi-cycle CEP-dependent FM is demonstrated to result from the interference of half-cycle HHG radiations, which is modulated by laser-driven nuclear motion. The mechanism of the CEP-dependent FM is further confirmed by simulations based on a simple algorithm in the time domain, which satisfactorily reproduces the TDSE results. The CEP-dependent FM encodes rich information on the correlated electron and nuclear dynamics, which paves the way for probing nuclear motion with attosecond resolution.
通过求解含时非玻恩-奥本海默薛定谔方程（TDSE），研究了多周期激光脉冲作用下H₂⁺产生的高次谐波（HHG）的载波包络相位（CEP）依赖性。研究发现，随着多周期激光的CEP变化，平台区的高次谐波呈现出违反直觉的频率调制（FM）。基于经典电子轨迹和时频分析，证明这种多周期CEP依赖的FM是由半周期HHG辐射的干涉引起的，该干涉由激光驱动的核运动调制。基于时域中的简单算法进行的模拟进一步证实了CEP依赖FM的机制，该模拟令人满意地再现了TDSE结果。CEP依赖的FM编码了关于相关电子和核动力学的丰富信息，这为以阿秒分辨率探测核运动铺平了道路。
