Dynamic Stabilization Of Alkali Metal Atoms In Intense Laser Pulse

In recent years,with the rapid development and improvement of laser technology,the study of atomic stabilization has become a hot topic.Atoms are affected by the laser field,and the ionization of atoms is usually positively correlated with the laser intensity,when the laser intensity increases to a certain threshold value,the ionization probability will not increase,but will decrease and then increase.This phenomenon is so called atomic stabilization.In this thesis,the time-dependent pseudospectrum method is used to numerically solve the three-dimensional time-dependent Schr?dinger equation with an accurate model potential containing angular momentum l to study the dynamic stabilization of alkali metal Li,K,Rb atoms.The main contents are as follows:1.By repeatedly solving the three-dimensional time-independent Schr?dinger equation,the model potential parameters of these alkali metal Li,K,Rb atoms are obtained.In order to check the reliability of our fitted potential parameters,the calculated energy levels were compared with the values in the NIST database.The results show that the calculated eigenvalues are in very good agreement with the values in the NIST database,the maximum discrepancies are about 0.15%,0.12%,and 0.13%,respectively.It can be seen that the model potential parameters of alkali metal atoms determined in this paper have high accuracy,which lays the foundation for the subsequent investigation of the stabilization research of alkali metal atoms.2.Based on the above work,dynamic stabilization of alkali metal Li,K,Rb atoms in the strong laser field is studied theoretically.The results show that the ionization probability of alkali metal atoms in different initial states shows a trend of first increasing,then decreasing and finally increasing as laser intensity increases;with the increasing of wavelength,the stabilization window of alkali metal atoms gradually moves to the direction of lower laser intensity.The origin of stabilization is interpreted by analyzing the population distributions of alkali metal atoms,we shows that electrons oscillate rapidly between the continuous state and the lower excited states.In addition,stabilization of Li atoms in the chirped laser field is also studied,and it is found that the ionization probability has an obvious dependence on the chirp rate.