An improved multi-step one-photon-absorption method for analyzing laser induced damage mechanisms of materials

the method of treating multi-photon ionization as some one-photon-absorption processes by introducing transition states has achieved good applications. In this paper, this method has been improved to extend its application scope of laser pulse width. In the improved model, some parameters without explicit physical meaning have been removed. For example, the parameter of energy fraction used for evaluating lattice temperature has been discarded, and the lattice temperature was evaluated according to an electron-phonon scattering process. Besides, more ionization mechanisms have been considered in calculating the electron density. The model described in this paper is suit for analyzing the damage processes induced by laser pulses with pulse width from femtosecond to nanosecond.