The generalized kinetics model for the description of the photoprocesses induced by ultrashort laser pulses

To explain the dynamics of the population of a quantum system excited by an ultrashort laser pulse, the generalized kinetic model is proposed and tested. It is shown that this model is accurate within the constraints of the applicability of the perturbation theory for any values of the laser pulse's duration and carrier frequency. By comparing the outcomes of our model to the two conventional methods and by precisely resolving the Bloch equations, we can assess the effectiveness of them. It is demonstrated that the usual techniques considerably overestimate the population values of the higher state of the excited quantum system outside the boundaries of their applicability. When using the Bloch equations is problematic or impossible, the suggested model can be utilized to characterize the population kinetics in the general situation.