分子超激发态（激发能在分子电离能以上的态）的光解动力学和光谱对于了解分子的电子结构、电子运动和核振动的相互作用等有非常重要的意义。本申请将利用两束激光四波混频方法产生可调谐的VUV/XUV激光，将分子激发到能量11-18 eV的超激发态，同时用另一束激光电离超激发态解离后处于Rydberg态的碎片，测量碎片速度成像和产生效率谱，以获得碎片的角分布、平动能分布、电子态分布等解离动力学和光谱信息。另外，利用多通道量子亏损理论结合高精度的量化计算对实验光谱进行归属和分析，通过光谱、动力学实验结果和理论分析相结合来理解超激发态解离机制。本项目集成了VUV/XUV激光泵浦-可见/紫外激光探测和离子速度成像等先进实验手段，类似的研究方法还未见文献报道。拟研究的分子有：O2，H2，Cl2，F2, HCl，H2S和H2O等。有5名博士生将参加本工作，他们将由此受到良好的科研训练。

The spectroscopy and dynamics of molecular superexcited states are very important in understanding the electronic structure and vibronic interaction of moleucles.In this proposal, we will employ four-wave mixing method to produce VUV/XUV laser to excite the molecule to superecited states (11 - 18 eV) and employ another visible/UV laser beam to probe the highly excited neutral fragments dissociating from the superexcited states. The fragment yield spectra and velocity map imagings of the fragments will be measured.The experimentally obtained results will be analyzed based on the quantum defect theory and ab initio quantum chemistry calculation method. The application of VUV/XUV pump-Visble/UV probe experimental method in combination with the ion velocity map techqiues to study the molecular superexcited states has not bee reported in the literatures. We will use this method to study some benchmark molecules O2，H2，Cl2，F2, HCl，H2S and H2O. At least five Ph.D students will work in this project and be trained to master the techniques of lasers, single particle detection and imaging, and theories of highly excited molecules.