Simple model for calculating photoionization rate in AVLIS system-2. Photoionization in mixed medium

In AVLIS system, the laser pulses propagate through an atomic vapor for a long distance. It has been shown by computer simulation that the laser interactions with target and non-target atoms modify the laser pulse shape and propagation velocity, resulting in the degradation of photoionization rate of target atom. In the previous paper, a simple model was proposed for calculating photoionization rate without computer simulation in the resonant media. In order to apply this method to the mixture of resonant and near-resonant atoms, the model was modified by introducing the decrease of laser propagation velocity by a near-resonant interaction. Based on this model, a simple formula was derived to connect the effective propagation distances in the resonant media and the mixture. It was found that, for the different incident laser conditions, the dependence of photo-ionization rate calculated by using the simple formula represent well the simulation results. (author)