Waveform Synthesis of Attosecond Optical Pulses: A Common Route to Attosecond Pump-Probe Spectroscopy and Nanoscopy in Aqueous Solution

当分子吸收光时，它的电子云几乎瞬间发生反应，随后在飞秒(fs=10-15s)内发生旋转核动力学。至皮秒(PS=10-12s.)时间刻度。例如，在光合作用中，叶绿素分子对紫外光的吸收引起电子偶极振荡，其周期在1飞秒范围内，随后其较慢的衰减和能量重新分配到核的自由度。在过去的几十年里，时间分辨光谱学展示了几个周期的飞秒激光脉冲可以用来引导核波包和控制基本反应的结果。然而，由于缺乏更短的脉冲，使得对亚振荡周期时间尺度上的电子波包的控制还没有被探索出来。是否有可能跟踪并最终更有效地控制反应动力学，从电子偶极力引发核运动的最早时刻开始？

When a molecule absorbs light, its electronic cloud reacts almost instantaneously followed by rovibrational nuclear dynamics on the femtosecond (fs=10-15s.) to picosecond (ps=10-12s.) timescale. In photosynthesis, for example, the absorption of ultraviolet light by chlorophyll molecules induces an electronic dipole oscillation, which has a period in the range of 1 fs, followed by its slower decay and energy redistribution to the nuclear degrees of freedom. Over the last decades, time-resolved spectroscopy showed how few-cycle femtosecond laser pulses can be used to steer nuclear wave packets and control the outcome of elementary reactions. The lack of shorter pulses, however, has left control of the electron wave packets on the sub-oscillation period timescale unexplored. Would it be possible to follow and, ultimately, more efficiently control reaction dynamics right from the earliest moments when electron dipole forces initiate nuclear motion?