Saturation of nonlinear susceptibility

摘要

The nonlinear susceptibility of atoms interacting with an intense laser field has been investigated using numerical solution of the time-dependent Schrodinger equation. It was found that the behavior of nonlinear susceptibility strongly depends on the intensity; it increases linearly in low intensity regime (Kerr nonlinearity), then saturates at higher intensity. Furthermore, it has also been found that the nonlinear susceptibility is substantially influenced by the onset of ionization.