Electron impact single and double ionization of argon

Stable two-mode, and three-mode oscillations due to the spatial hole burning effect were observed experimentally with the increase of the pump power ratio in a laser-diode pumped sub-nanosecond microchip Cr,Yb:YAG self-Q-switched multimode laser. The stability of the output pulse trains was attributed to the mode coupling through antiphase dynamics between different modes. Modified multimode rate equations including the spatial hole-burning effect in the active medium and the non-linear absorption of the saturable absorber were proposed. Numerical simulations of the antiphase dynamics of such a laser were in good agreement with the experimental data, and the antiphase dynamics were explained by the evolution of the inversion population and the bleaching and recovery of the inversion population of the saturable absorber.