Optical breakdown in dielectrics induced by high intensity femtosecond laser pulse and simulation of breakdown footprint

摘要

In this paper the dynamics of optical breakdown in dielectrics induced by femtosecond laser pulses was simulated numerically. Using rate equation and time and space dependent intensity for laser pulse the free electron density in focusing volume was calculated. In the calculations propagation of laser pulse through the focusing volume was considered. The temporal and spatial free electron density was used for simulating the footprint of the breakdown region in the focusing volume. In these calculations the influence of the laser power was investigated. The results and simulation show that lower laser power can generate asymmetric breakdown trace while the trace becomes more symmetric if the breakdown is generated by higher laser powers.