Simulations of femtosecond laser excitation in bulk silica

Abstract

A model to simulate the interaction between ultrashort light pulses and bulk fused silica is presented. Starting from Maxwell's equations, an equation for computing light propagation is derived using the slowly varying envelope approximation. Two third order nonlinear effects, the Kerr effect and Raman scattering, are taken into account. The model also takes into account the generation of an electron plasma by strong ?field ionization and impact ionization. To describe this process Rethfeld's multiple rate equation is used. The transmission profiles predicted by the simulations are compared with experimental transmission images of electron plasma in silica.