Study On The Response Function Of Absorption For Atomic Hydrogen Induced By Laser Fields

Laser pumping is an efficient way to study structure of atom(molecule).In this way,we can study those structures via detecting the energy distribution of photoelectrons which come from ionizing atoms by a high-frequency laser.But the environment has greater effect on the photoelectrons and precision of experiments.in order to deduct the effect of environment,a new method was development.In that way,absorption spectrum of atom was used to replace the energy distribution of photoelectrons.The reason why we can use the absorption spectrum is that the atom can transition from the low level to the high level when ultraviolet photons interact with atoms and we can use a infrared laser to study the exciting atoms.In this thesis,we mainly investigation:Firstly,Split-operator method is used to the numerical solution of time-dependent Schr?dinger equation of one-dimensional hydrogen atom.The response function of absorption of atomic hydrogen driven by one-color extreme ultraviolet(XUV)light is studied.Compared the influence of results from empirical Gaussian and calculated exponential decay function,it is found that the response functions of absorption have no obvious change,except the quantitative values.Secondly,the response function of absorption for atomic hydrogen driven by an infrared(IR)laser and a XUV light are calculated.The results are similar to ones for hydrogen driven by XUV light.It suggests the usual Gaussian decay function is simple,which does not need to calculate the excited lifetime of atom.