阿秒科学前沿开拓与强场量子相干控制研究

李儒新

摘 要：该研究产生更短脉宽、更高光子能量与更高亮度的阿秒相干光源以及原子分子中阿秒电子波包的探测和控制，预期目标主要包括：（1）实现亚飞秒时间尺度和原子级空间尺度内实时观测和控制电子动力学行为；（2）在多电子弛豫过程中，电子重排、电子-电子碰撞动力学等多电子复杂动力学研究中取得若干突破；（3）揭示有重要意义的化学反应的电子动力学物理本质。探索阿秒脉冲作用下物质的电子动力学新规律及其应用。开展中红外激光与气体介质相互作用产生高次谐波的实验和理论研究，采用双色场方法获得高次谐波连续谱，为进一步将阿秒脉冲宽度测量和光子能量推进到“水窗”做准备。从理论上深入了解分子结构和反应通道和分子高次谐波之间的联系，以及和激光参数之间的关系，为实验研究做准备。获得了一些系列研究成果，包括发现太赫兹辐射波形可以通过改变驱动激光脉冲的CEP而实现控制，在光丝等离子体中太赫兹辐射发生极性反转，利用周期量级极端超快激光脉冲光场自身的不对称性获得增强的太赫兹辐射；发现基于独立电子近似的遂穿模型不能解释次序双电离中的许多现象等。

关键词：阿秒 超快 量子控制

Abstract： This project work on the generation of the attosecond pulse of shorter pulse width， higher photon energy with higher brightness and the detection and the control of the attosecond electron wavepacket in the atoms and molecules including： （1） achievement of real-time observation and control of the electron dynamics during the sub-femtosecond timescale in the atomic-level spatial scales； （2） detection of the multielectron dynamics， e.g. multi-electron relaxation process， electronic rearrangement， e - e collision dynamics， etc； （3） revealing the electron mechanicsm of the chemical reaction kinetics. To explore the new mechanism and the application of the electron dynamics during its interaction with the attosecond pulse. We have carried out the study of the high order hamonics generation with mid-infrared laser experimentally and theoretically， by using the two color scheme to obtain high harmonic continuous spectrum， for further attosecond pulse width measurement and pushing the photon energy to the "water window" region. We also study the relationship beteween the molecular structures and reaction pathways and molecular harmonics theoretically， as well as the parameters of the laser pulse， for the future experimental study. We have obtained some results including the discovery of terahertz waveform control by changing the CEP of the laser pulse， polarity reversal of the terahertz electric field during the filamentation and the plasma， using the asymmetry of the few-cycle laser pulse to enhance terahertz radiation； discovering that the independent elecctron tunneling model can not explain many phenomena during the sequential double ionization.

Key Words： Attosecond； Ultrafast； Quantum control

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