双色脉冲场量子调控H_2^+的光电离动力学  

Quantum control of ionization dynamics of H_2^+ with an intense two-color field

作　　者：张季[1] 姚洪斌[1] 

机构地区：[1]新疆工程学院新能源材料重点实验室,乌鲁木齐830091

出　　处：《科技导报》2016年第7期90-93,共4页Science & Technology Review

基　　金：新疆维吾尔自治区自然科学基金项目(2013211B32)

摘　　要：利用精确求解核与电子运动的三维含时量子波包法,理论研究了双色激光脉冲场(790-395 nm)量子调控H_2^+的光电离动力学方案。与单色场790 nm和395 nm相比,H_2^+在双色脉冲场(790-395 nm)中的电离几率明显增强。通过改变双色脉冲场的初始相位差,H_2^+的光电离产物的空间非对称性分布几率可达52%。该调控方案的理论机理是通过精确操控激光场的瞬间波形,使其电场强度在正、负方向上的非对称性达到最大值,进而达到对光电离动力学过程的高效调控。通过系统分析活跃电子在强场缀饰势阱中的运动,阐明了H_2^+的光电离几率和产物空间分布随电场强度的变化关系。该研究结果将为后续的量子调控光电离动力学实验提供科学的理论预测和指导。An efficient scheme for controlling the photoionization of H_2^＋ is investigated by using an accurate 3D time-dependent wavepacket method. Compared with the one-color filed, the ionization probability of H_2^＋ is greatly enhanced in the two-color（790-395 nm） field.By manipulating the relative carrier- envelope phase of the two- color field, the highest asymmetry modulation relative to the laser polarization reaches up to 52% in the ionization of H_2^＋. In our control scheme, the subcycle waveform of the two-color field is manipulated to control the maixmum field amplitudes in the positive and negative directions. The sensitive dependence of the subcycle waveform in the asymmetric ionization of H_2^＋ is explained by tracing the laser-driven motion of the electron in the dressed double well potential. In addition,the basic mechanism behind the enhanced ionization of the molecule is revealed, which provides a practical guide for the optical control of the ionization dynamics in future experiments.

关 键 词：量子调控 含时波包法 光电离 激光场 

分 类 号：O43[机械工程—光学工程]