激发态在分子高次谐波辐射中的效应

项目名称： 激发态在分子高次谐波辐射中的效应

项目编号： No.11274090

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 陈彦军

作者单位： 陕西师范大学

项目金额： 75万元

中文摘要： 分子的高次谐波辐射是目前强场物理研究的热点问题之一。分子的谐波辐射和分子的基态轨道有紧密的关系，因此利用谐波辐射人们可能在超快时间尺度内探测分子的结构。然而最近的研究表明不仅分子的基态，分子离子的激发态（具有比基态更高的电离能）和分子的激发态（具有比基态更低的电离能）都可能对谐波辐射产生重要的影响。本项目拟通过数值模拟和理论分析，系统地研究这两种不同类型的激发态在对称分子以及不对称分子高次谐波辐射中的效应。研究这两种激发态对谐波辐射的贡献与分子取向的关系，与激光强度和激光波长的关系，以及这两种激发态贡献之间的竞争机制。另外，本项目还将详细研究不对称分子的固有偶极子对这两种激发态贡献的影响。这些研究将为利用谐波辐射在超快时间尺度内探测分子的结构和动力学提供一定的理论支持。

中文关键词： 分子谐波辐射；激发态效应；固有偶极子；极化；

英文摘要： High-order harmonic generation (HHG) from molecules is a hot issue in strong-field physics. It has been known that the HHG is closely associated with the ground state of the molecule. Accordingly, one can image the molecular structure using HHG with high resolution. However, recently, it is shown that not only the ground state of the molecule, but also the excited state of the molecular ion (with the higher ionization potential than the ground state) as well as the excited state of the molecule (with the lower ionization potential than the ground state) can contribute importantly to the HHG. In this work, we will explore the roles of these two excited states in the HHG from both symmetric and asymmetric molecules numerically and analytically. We will study the influence of the molecular and laser parameters, such as the orientation angle, the laser intensity and the laser wavelength, on the contributions of these two excited states in detail. We will make efforts to clarify the competition between the contributions of the two excited states to the HHG. In addtion, the influence of the permenant dipole of the asymmetric molecule on the contributions of the two excited states will also be investigated detailedly. These studies are expected to provide suggestions on probing the molecular structure and dynamics u

英文关键词： Molecular high-order harmonic generation；Effects of excited states；Permanent dipole；Ellipticity；