激光驱动气体等离子体发射太赫兹波的研究

It is great interesting for terahertz(THz) wave because its special characteristic , and its playing important roles in many scientific and application fields. In this project, we will study the qualities of THz wave emission of gas plasma drived by laser fields.By relying on numerically solving time-denpendent Schrodinger equation of atom (or molecule) in laser fields, we will investigate the properties of the exicitation and ionization of atoms(or molecules) in gas, and understand the discontinuum and continuum THz emission of plasma.Based on the excitation of atoms(or molecules) and the Einstein coefficients equation,we study the relation between the frequancy of the discontinuum THz wave emission and the different gases; Based on the ionization of atoms(or molecules) and the statistic average method, we study the residual current in plasma as a function of time and space, and understand the relation between the emission intensity of the continuum THz wave and the different kind of gases, and the parameters of lasers. Finally, by numerically solving Maxwell equation, we investigate the phase matching of THz wave propagation in plasma in order to enhance the efficiency of the THz wave emission, and achieve the control of the THz wave emission. In this project, we wish to provide the theoretical basis for selective frequency of the discontinuum THz wave, and for high power output source of the continuum THz wave emission from plasma.

由于太赫兹(THz)波具有独特的性能并在许多科学领域和应用领域发挥重要作用而引起人们的重视.本项目研究激光作用在气体上形成等离子体发射太赫兹波的性质。通过数值求解气体原子(或分子)在激光场中的含时Schrodinger方程，研究气体中原子(或分子)的激发和电离特性，由此了解等离子体中发射不连续和连续太赫兹波辐射特点.由气体原子(或分子)的激发特性和爱因斯坦系数方程研究不连续太赫兹发射频率与气体种类之间的关系；由气体原子(或分子)的电离特性结合统计平均的方法，研究等离子体中的离化电流随时间和空间的变化，了解连续太赫兹波发射的强度随气体种类、激光参数之间的变化关系.最后通过求解Maxwell方程，研究太赫兹波在等离子体中传播的相位匹配情况，以提高太赫兹波的发射效率和对太赫兹波发射的控制.我们期望实现对不连续太赫兹波的频率可选择、对连续的太赫兹波能输出强度高的等离子体波源提供理论依据。