Analysis of avalanche mechanisms in short-pulses laser-induced damage

A theory based on the rate equation of free electron is used to analyze the process of free electron multiplication in optical materials under the laser irradiation, specially researching on the effect of avalanche ionization on the electron multiplication and material damage threshold. Numerical investigation with SiO2 is processed using this theoretical model, and damage thresholds under different avalanche models are analyzed. The result shows that during research on the energy charge between electron and electromagnetic field, the probability of avalanche ionization should be considered. Under this assumption, the numerical threshold gets well with the experimental result.